The finned dart sabot rounds have been some of the most difficult things for me to get to work and I'm dealing with half the scale you are. You can't put a wad behind the fins because that will just crush the fins. The sabots double as the gas seal. Most of the darts we have tested (CanaDart, Anferov bullet, Dynaslug, and Sauvestre) have lugs on the shaft that match up with lugs on the sabots. Almost all the pressure acts on the sabots and pulls the dart down the barrel as the dart is locked onto the sabots. A common failure was when we tried to push the rounds too hard - it stripped the lugs right off and the sabots went flying at a high speed and the dart followed along at a very low velocity. The video we just did with the CanaDarts used very brittle 3d printed parts. I had to use a small 25 grain charge of Pyrodex and a spoonful of coffee as an inert buffer to fill the space. They worked OK but we were only getting about 500 to 600 fps.
Oh snap! Wow! Thanks for tuning in! I just recently found your channel and subscribed and your sabot dart made me realize that the rods were supposed to be threaded(and why 🤣😂) like two days before this video came out. I’ve so appreciated the knowledge that you share on how to cushion rounds and the ways you load them and the gas seal ideas. I hope you truly know how much I appreciate your channel and I didn’t expect this to even make it anywhere near a comment from you! I will for sure take your tips into account and get a working V2 version in the future. I greatly appreciate the tips and you tuning in in the first place! Keep making those amazing videos.
@@TheCannoneer One of my viewers left a comment saying you were having trouble with your sabot darts so I had to check it out. The viewer-created projectiles have been fun to do and I've been surprised at the creative ideas people have sent. People have been telling me that we need to scale things up to something like you are doing so it is great that you are taking that opportunity. The 12ga. stuff keeps me busy.
@@taofledermaus I was checking out the back catalog and there's some seriously weird things folks come up with. I have a hard enough time making a big round lead ball half the time!
Your problem is simple, the sabot is supposed to lock on to the penetrator and is used to accelerate the penetrator down the barrel with the sabot releasing and flying free once the penetrator exits the barrel. Your base was is crushing the stabilizing fins upon ignition.
ok, so here is my suggestion: Since you 3d printed the fins I think that you could/ might consider printing a hollow mold of those same fin designs for the rear portion and then using perhaps a resin filled with carbon fiber fibers mixed in and applied as evenly as you can. Perhaps a mold design that would snap together and allow excess material to flow out of tiny port holes that when cured could be cut or filed off. I would also be interested if you used the same method to cast a set of concrete fins and again allowing the discarding front portion of your sabot to simply be 3d printed out of the current materials. Only suggestions so please do not listen to me, but I think that it may work.
I think the molded fins are a good idea so I’ll have to figure out how to get that working or weld them on! I’ll probably make a few different versions from everyone’s suggestions!
Well I was in Armor.. The petals are only there to keep the penetrator center in the bore and nothing else, so try to leave the petals completely loose so they separate the instant they leave the bore.
It seems to me the PLA fins might shatter before leaving the breach, due to the base plate being slammed into the much more massive steel penetrator rod. Try metal fins? Or redesign the fins so the rod touches the plate, that way they won't be crushed between the rod and the plate on firing.
Me aswell as some of the discord from SIMULATION BROS will try to help you by putting together a design, i'm thinking of making a lugged sleeve for the sabot
Your biggest problem right now is your APFSDS projectile is getting left behind by the sabots because there's nothing really holding them together. Real APFSDS rounds are held mechanically to the sabot by a series of machined grooves in the sabot and projectile locking them together. The sabot has the majority of the surface area and is where the majority of the "push" from the gunpowder goes and it pulls the APFSDS projectile down the barrel along with it. What might work best in your case is to make the metal rod go down to the base of the fins and have an additional base to push the projectile from behind. That way the majority of the force is the new base pushing on the rod from behind instead of trying to pull the rod from the front. You would have to redesign your sabot a little to make sure it could also hold up to getting pushed from behind, but that should be mostly making the rear section thicker. You could also try printing your fins thicker and from Carbon Fiber TPU, which is significantly tougher against sudden shock and impacts while still being pretty stiff. It's pretty abrasive on brass nozzles so you would need to get at least a hardened steel nozzle.
I don’t know if I can print carbon fiber on my printers! I’ll have to look for sure! I was wondering what the all thread was about inside them but that makes complete sense. Keeps everything together.
@@TheCannoneer All you really need is a hardened steel nozzle for your printer(Short term) and hardened steel/replacement extruder gears(Long term) if yours are brass. If yours is a threaded removable nozzle it's almost certainly a standard size nozzle that's widely available anywhere that sells 3d printers and accessories. If its something more proprietary, like from Bambulabs, they usually sell hardened nozzles or may come standard on their high end models.
@@tu-jx6wh there are also tungsten carbide nozzles as well, they don't wear at all, they will basically last a lifetime unless you're extruding filament loaded with diamond powder, which I don't think exists...
The easiest answer for the rod is to make it from a threaded steel rod and have the three print sapo interact with that you could also easily machine a metal tip that you could then screw on to that rod
@@TheCannoneer Using a section of all-thread as your projectile might be a quick and dirty way for your sabot to retain the penetrator rod as it goes down the bore. Keep the sabot pulling by threading its inner section to match the rod.
Taufladermaus did a video like last week shooting some flechette rounds. It seemed like the sabot fully encased the flechette and had a cup shape at the tip above the tip of the projectile so once it's out of the barrel it catches air and splits instantly. I feel like that would work well here.
I shall have to check his channel out some more. I didn’t even know he existed until recently when y’all started suggesting it and he’s got some many cool designs! Thanks for the tip!
@@TheCannoneer I was going to suggest that channel but figured you knew. The 12ga designs would translate well to your barrel I bet. The other comment re a concave cup leading the sabot parts sounds right on. Clean separation
1. Don't make pressure push on the fins with the pad 2. add grooves on the rod so the sabots have tight grip 3. Add aerodynamic surfaces on the front of sabots that will better push them apart after leaving barrel - I really like your creativity 🙂
Much appreciated! I didn’t know these rounds were pushed by the sabot and not the fins when I made these but yall have wonderfully explained that so I was unknowingly putting pressure on the wrong parts. We will be a redesign and get these working! Thanks for the tips!
Here is an image of what Martin is talking about. I believe these sabots are normally split lengthwise into three pieces. pbs.twimg.com/media/DmcwFhqVsAAGF3C.jpg
The sabot needs to pull the dart from the front. Not be pushed from the back. In all APDFS rounds from 7.62x51 DU to 120mm. The sabot pulls from the front. It's also cupped at the front to catch the air and separate from the dart as quickly as possible after it leaves the barrel. I'm sure people have mentioned the grooves normally found on darts so the sabot doesn't slip. An interesting fact. Surplus 7.62x51mm DU has made it onto the civilian market. It's really rare but cool.
4. Keeping it subsonic also helps. Typical black powder shot is transonic -the worst possible speed for this purpose. I've tested this kind of things with air rifles. Just a half gram piece of florists wire with rice paper vanes and a wood plug seal. From a low power target rifle , ca. mach .4 speed, they work fine, consistently stick point first on 4" board at 10 paces. From full power mach 1.2 vermin rifle they come out sideways.
On APFSDS, dart shaft's positive ribbed while Sabots' interior's negative ribbed so the sabot grips the dart shaft and doesn't blow out. Current construction is a soft "rubber gas check" then delicate plastic fins, then metal dart. On firing, the rubber and plastic fins probably give some or shatter. Maybe rag packing over powder then a short wood cylinder behind the dart as a rigid pressure bearing point. The solid shaft should carry all the way back to the bearing point - wood dowel -( the fins should end at the back of the dart). The sabots look sound, they only need center the dart, elastics alone should do. ..just a idea... besides, wood is cheap ! ..cheaper...
@TheCannoneer Definitely check out how shotguns use a wad with a bit of spring-like material instead of a solid puck to push the round. It should help with the fins breaking on firing! Loved the video btw
Someone pointed out the TPU base is probably was just piercing a hole through and blowing everything apart in the barrel which makes total sense. I’ll have to revisit the metal fins idea and a few harder base plate materials….
Don't put wadding of any kind behind the fins, that's only going to load them and destroy them. Serrate the penetrator and have the sabot grip the serrations to pull it through. If spacing and a smaller charge doesn't help then you'll have to go with an all metal dart. Normally the fins are in the propellant explosion, they are NEVER pushed.
There's another guy on youtube called flasutie id hit him up and ask him for ideas since it's one of his specialties and he might be able to help i hope you get it to work and i can't wait for the next video.
taofledermaus is another good resource if you haven’t discovered him yet. He basically does the same thing just with 12 ga shotgun loads. There are several videos of “apfsds” rounds going through iterations to find what works. I imagine it would be a good resource since I think people have gotten them to work, though on a smaller scale with about the same acceleration. Idk how that scales to a small cannon though.
@@rofllcats I just recently found his channel since yall mentioned it! His loading techniques with the cork seems super handy and I will be sure watching more of his videos for some tips!
Thank you guys so much for all your wonderful ideas on how to improve this round! We will get this working in the future with all of your improvements. Thanks for your support!
For a muzzle loaded apfsds you need a flat bottom piece that goes behind the flechete and support the sabot extrude a rod enveloping the flechete 30% of it is the base or the piston this is a single piece the remaining 70% is the sabot and you cut it in 2,3or 4 parts from the top and the head need a cup or c shape to catch the air to peal apart And attach a pvc tube to the reloading rod so it doesn’t touch the flechete only the sabot Edit and use paper strips to hold it instead of ruber or tape
And I don’t know if it’s will be useful but I shot a “apds” on my air rifle using a mold to envelop half of a nail in compressed wet toilet paper it works well both as a single solid piece or as a solid base and 2 peals apart mid ,it’s shrink a little wen dried but you can umidify (don’t wet it again)before shooting
Two options for making the penetrator better. Either make the overall length of the penetrator shorter or the fins longer. That would help it as far as staying on the flight path
1) I'd try a different 3d printed material- I've used PETG sabot rounds in my muzzleloader, they don't seem to break up at all (less brittle) 2) I'd try a softer wad- maybe felt layered or t-shirts layered 3) That penetrator needs to be nose-heavy and tail-light. The first 1/4-1/3 of the penetrator should be lead or steel, the body should be composite, and the fins 3D printed Love this channel dude, keep up the great work! I hope these suggestions make it to you!
I dont think the 3D printed fins are going to hold up to the forces involved. An alternative design would be a yo-yo style to generate the spin. Sounding rockets use a yoyo to despin, but a modified design could also spin up the projectile. There are two ways. The first design is simpler, you attach a wire to the Sabot petals and spool the wire around the projectile. As the petals are flung outwards, they unwrap from the projectile, spinning it up. The second way would be harder but more similar to rocket designs, you would need to have some small weights on the end of wires with a slight rotation already present, if the wires are winched inwards to bring the weights closer to the projectile, the moment of inertia will decrease and the projectile will exponentially increase in rotational speed to keep the angular momentum constant. Having the wires pass through holes in the projectile and anchored back to the cannon or the sabot could winch the wires inwards if done right, the other ends of the wires just having some weights attached to them. The best way to think of this second idea is a figure skater pulling their arms in to spin very fast, the same principle will apply to the sabot if you can pull mass inwards to the center of rotation somehow.
You could also just try to make something more aerodynamically stable. The idea of the fins, besides spin stabilization, is to put the center of drag behind the center of mass. Alternatively, if you were to cast lead onto the nose of the projectile, it would be nose heavy and much more stable. Lead is over 50% more dense than steel, and very easy to cast. Real APFSDS rounds use tungsten or depleted uranium for the penetrator because of the increased density.
Several people have made one suggestion of cupping the front flange as an air catch when it leaves the barrel the air will catch the fina pulling them away from the penetrator. But the biggest thing for stability is not using a pusher behind the penetrator. The sabot needs to pull the core out of the barrel. This is because without a perfectly balanced core any slight instability is amplified by the pusher. One of the easiest ways to get the sabot to lock in to the core is cut a small groove around the shaft of the penetrator. The with the sabot add a small lip on the inner diameter to fit into the groove.
OH YEAH jsyk, real APFSDS rounds have ledges / steps on the penetrator that interface with some on the sabot, so the sabot actually drives the central projectile. here, the sabot may just slide off the penetrator during firing as there is no mechanical interface
I see good comments here. Mainly I would just make the discarding part of it a chunky cylinder that fills the bore and encapsulates the fins in addition to the penetrator to support everything as well as possible. 3D printing lends itself to chunky designs and your fins are too flimsy to be carrying all that acceleration by themselves. You might even see about adding a steel cross pin into the penetrator a little further up that can also key into the discarding sabot to take some of the stress off the fins. This would allow the sabot to pull directly on the penetrator taking some of the force away from the back. I imagine that even if the fins are surviving, the penetrator is getting driven back through the fins and through your TPU pushers like the penetrator that it is lol
For old school artillery, you need old school ammunition. Forget the 3D printed fins, just make a nice penetrator spike and fit it with a suitable discarding sabot. Bore a hole through the end of the spike and tie some hemp line with a monkey fist ball knot made a few thousandths shy of diameter of the barrel. Leave about 4 - 6 inches of line between the spike and the knot. Soak the line in water over night, this will keep it from combusting when fired. Ensure the monkey fist knot is still about the same size as the sabot outside diameter, dry it out a little if its swelled with water, coil the line to butt the knot up to the sabot then load the lot with a wad to keep the monkey fist off the powder. The ball should trail on the line when fired, inducing drag and stabilizing your penetrator. With some fine tuning on the size and weight of the rope ball, you should be successful.
If you look at the tank's APFSDS, it's the back "bulge/ring" of the sabot that seals the case and is pushed by expanding gases (the front one keeps penetrator straight). The fins are actually inside the propellant when loaded. I think in your case those TPU disks simply push through stripping fins, because the penetrator is not supported well enough. Maybe redesigning the sabot in a way that it is pushed directly (so the sealing bulge/ring is behind the fins), and adding on the inside something that would grip the penetrator along its length would help. Anyway - great video.
That makes total sense and when I found one of those discs it did have a hole in it. I bet you’re totally right as to what’s happening inside there. I didn’t realize how those rounds really worked until y’all explained it and that makes total sense. We’re pushing from the wrong part and the stress is on the wrong piece. Much appreciated for the tips!
@@TheCannoneer yeah apfsds is really cool in its simple science. my countoured fin base cap idea was more of a solution geared towards your current design layout. but if you actually redesign entirely and aim for the proper shell mechanics i think youll see much more success and much easier than trying to improve your current one.
As much as we love 3D printed projectiles, they have limits as far as surviving violent acceleration as you would see in a black powder cannon. It's not impossible, but requires additional design improvements to prevent the projectile from being obliterated to avoid the plastic from being destroyed during firing.
Oh snap! Thanks for tuning in! You guys have great videos too! I’m hoping to get a working version with some of the tips everyone here has been suggesting. I truly appreciate you guys checking us out! If you guys are up from some exploding cannonballs…. Hahaha.
The sabot of the round itself is suppossed to be exposed to the pressure gasses, not a baseplate behind the round. the fins were clearly not strong enough to hold all the force. The problem with your round is that the sabot will get launched out without the dart if you had no baseplate. To fix that you need grooves on the dart and the sabot so they get locked together while still in the barrel.
That makes complete sense when you look at the cross section. I’ve got to make it work the other way around… as it’s being pushed from behind on the fins now. I didn’t put that together until now. Thanks!
Plastic guides should be attached to a steel rod, the easiest way to do this is with the help of ribs around it, the parts should not be attached to each other and come off immediately after the projectiles exit the barrel, then about the metal bar itself, it does not represent anything, there is no armor-piercing cap, core, shell made of soft metal...
You might try TIG welding some steel fins onto your penetrators. You might need a jig to hold the fins in place wile you weld though, to keep the heat from warping them out of alignment.
The sabot must be metal. Let me explain. If you look at the m1 abrams, the whole entire system doesn’t have any buffers between the shell and the casing. The sabot must also be metal if the projectile is metal, that way the cannon pressure wont make the projectile sheer off any metal holding the projectile in place. I recommend CNC aluminum, it should be strong enough, plus you can print it into whatever you want. Edit: if not already, it should be properly held together on the inside. That way the projectile cant move forward or backward in the sabot, so then the sabot can cleanly release after the cannon fires and it has left the barrel.
You need to create break groves and only have the thinnest pieces of material holding them together. The tape & bands are flexible and do not break apart. You need to guide the break apart and weaken the material along those break up sections so the force of the wind is stronger and more than enough to break the material. You’d better off using a more brittle material like dried cardboard or very brittle plaster. You’re not using even close the power of a shot real sabots experience when fired so you need to compensate by using material that’s more brittle to get the proper break away affect you’re after
It seems like the main issue is the power of the Canon is pushing the fins of the Sabo through the shaft basically destroying the fins before it's even leaving the barrel to fix this it would be better for the shaft of the Sabo to go all the way through the fins
Theres alot of good information in the comments to recap the main changes that you need to make if you want this to work 1. you cannot pit wadding behind the fins bc the fins cannot be made strong enough to be load bearing and will be crushed by the wadding 2. In a normal sabot round the petals interlock with grooves on the projectile and the petals are responsible for pulling the projectile down the barrel and obturating the barrel (thus taking the load of the fragile fine) Also a note on terminology, what you refer to as the "petals" the parts the hold the projectile are called the "sabot", and the part you refer to as the "sabot" is the projectile
OMG you actually did it, amazing! sad that they didn't work. maybe having metal fins welded to the penatrator would work? Also nice voice over and always great camera work. If you get the APFSDS rounds to work ill send you a nice bottle of Dutch liqueur!
I try to make sure I keep my promises! I’ve still got the flechettes lined up but I can’t shoot them at our normal ranges. Only one will let us and it’s an hour from my house so I don’t get there often but they will be one of these days. I’ll raise you a glass on the working video one of these days hopefully!
Gotta be honest, I would really like to see some explosive rounds, but the risks to you and the cannon would probably be too high. Also probably very illegal…
The problem is the sabot petals and fins are being shattered by the force of the blast, the obturation you are using is getting blasted around the fins and petals Make the fins stronger, make the dart body do to the base, support the base with stronger obturator pads something that the dart metal won't penetrate. The petals are normally mechanically connected to the dart body you could do this with a few pins sticking out about 5mm each side about 5 or 6 at one inch intervals midway down the dart body.
Technically it’s an “antique” and the reproductions, as long as they fall under the black powder, muzzleloading, non cased ammunition, the reproductions are classified the same. Very similar to the black powder rifles and you can make one or buy one online and have it shipped to your door no paperwork needed. Now the ammunition can be a DD if it’s explosive or if the cannon is breach loaded the ATF will come calling you. Good question!
Try extending the penetrator to the Base of the fins, so it is in contact with the wad, and can absorb the brunt of the "g" forces. The fins are probably being compressed to failure.
No worries at all! As far as I can tell 3,6, and 9 pound cannons were the norm in the revolutionary war. Ones Our size would have been fielded but as an anti personal cannon at closer ranges than the big guns. As for the civil war they had all kinds of different sizes but 3” rifles guns and 12 pound smooth bores were their go to. I hope to get a 3”rifles gun if the channel gets big enough. Thanks for tuning in!
I'll go with what the others have mentioned, the finas will never support being the part receiving the force, the penetrator needs a way to lock it to the sabot while in the bore, abd the fins need to be a tougher material.
Food for thought... The APFSDS has grooves which lock it into the sabot. Maybe if you turned a few grooves into the rod, or use a peice of allthread, it may adhere better to the sabot. Also, you need a pushing charge, not a forcing charge. Perhaps loading your cannon to the training load specs might change the pressure dynamic. 😉 And yes, pin the fins. They want for a mechanical connection to the rod.
I’ve realized that I’m trying to reengineer the design to be pushed from the base and not from the sides and y’all have wonderfully explained that to me which I much appreciate. I’ll pin the fins! If I’d have quite known how they are supposed to work I’d probably have done some rethinking!
I hope you manage to get the APFSDS running. Why don't you build your own cannon in the future ? Made from a super alloy, 2.5 inch wall thickness so you can use fast burning NC powder for extreme muzzle velocity. For the APFSDS rounds, heavy tungsten alloy would be better, maybe even with a carbide tip and a TICN coating. I would love to see that. No one on UA-cam has ever tried this and I think it would get you a million clicks👍
We actually built our current cannon but we didn’t have the channel in mind so we didn’t film it… I’ll have to make a new one at some point and film the process! Sadly cannons have to be black powder or they are considered destructive devices and then the ATF gets involved…
Try using a stabilizing cone instead of fins. Tank training ammunition is cone-stabilized rather than fin-stabilized. Without machining the penetrator to lock onto the sabot petals, that might be the most durability you can get out of this design. Also, ensure that your rear TPU disk ("wad"?) is applying pressure directly to the metal rod, and not the cone or fin stack. Mounting the cone or fins a bit forward of the base of the penetrator will help ensure that the bulk of the force is absorbed by the metal rod and not the printed part, which should leave aerodynamic forces after the round leaves the blast envelope as the only thing the printed part needs to withstand.
You’re not supporting the penetrator. When you fire the shot, the plastic/resin is way lighter than the steel, the plastic is accelerating faster than the steel thusly totally destroying the fins and sabot. It’s a physics problem. Just like no seatbelt on a crash test dummy in a 300 mph crash, the dummy goes flying(the sabot) car doesnt
isnt the main problem the weight of the projectile? because the point of APFSDS is to have big force in small area but your looks a bit light and maybe thats the problem? im just guessing but you should try heavier material or just APCR. (i understand that you try to replicate the APFSDS but for such a small cannon it doesnt even make much sense) but still pretty cool project!
I THINK i figured out the 2 key issues. 1.) The Dart itself, is Notched into the Sabots, And they "Pull" the Dart down the Bore. 2.) Nothing staying intact Because you 3D Printed everything. You cant put Plastic with Ballistic Pressures and Heat.
You can’t use PLA and expect it to work, let alone the design- you should be using something with some flex like Carbon Fibre PETG, ABS or maybe TPU is best
I think you have two big problems, one of which is related to PLA being very brittle. There is no way that the PLA fins survived being pushed by the wad. One thing I would suggest is making fins out of sheet steel and either cutting fins and welding them to the rod or bending the sheet to make two find and spot welding in the middle (like mortar rounds). The second problem was apparent when you pulled out the rod from the sabot. You shouldn't need the TPU wad, the seal should be provided by the petals and they should "pull" the rod along. You need to cut some interlocking surfaces on the rod so you can't pull it out of the petal. So: 1- welded metal fins 2- grooves to fix the sabot Or: Dispense with the sabot, use the wad and weld front and back fins to keep the rod centered. If the wad is providing the seal, there's no need for sabots. Hope this wall of text helped.
One of your problems is sabot drag. For this more is better as it provides the force that causes separation. Black powder is likely to give you little more than 1000ft/s. An MBT sabot round exits the barrel at more like 6000fy/s. IE 36 times more sabot drag. The front of the sabot is a higher drag design too.
I'm not sure what plastic you are using, but I would look into what you could use that can take the heat and pressure of the black powder. Sabot's are one piece, fin and dart. And they're all made of the most dense material available. (Tungsten, uranium, etc.)
Can you print a 38mm x 40mm plug with a short, centered protrusion the same diameter as the penetrator? Then print the fins with a center hole the same size so you can set the pin against the rod? This would direct the propellant's force somewhat more directly through the rigid centerline. Hopefully the plug will even out the force of the detonation on the round. Super interesting, folks are on to something with the material durability question. When you get this sussed build a HEAT round. 😉
This is a learning experience, and it's great fun watching your imagination. There will be many suggestions, and the fun of it will be in watching which paths you choose. But whichever path you choose, be sure to get married & have children.
a few things I see that can be improved: first APFSDS Penetrators and the Sabot have some sort of grooves that basically are supposed to do what you did at the end with the rubber band as well as giving the sabot enough friction the keep them on the penetrator before firing , second: you souldn't strip the sabot parts together to allow them to seperate easily after leaving the muzzle, and third: dont use that base plate at the back. you basically replace the actual sabot with that thing, which causes a lot of issues. Probably it also would help to try a material with a slightly better durability like ABS instead of the PLA.
Both the penetrator and the sabot need to be threaded so that they grib each other (i.e. a matching interlocking thread), otherwise the sabot (which is trapping the gasses) will simply slide straight off and out ahead of the penetrator, transfering little to no forward momentum to it. The first goal therefore is to make sure the sabot gribs the penetrator tight until it has left the barrel, where wind resistance (drag) then forces it to seperate from the penetrator. I'd suggest trying with a thread that is slanted away from path of travel on the penetrator itself, also refered to as a buttress or sawtooth thread, so as to facilitate a smoother seperation of the sabot from the penetrator as soon as it leaves the barrel,. In other words imagine a penetrator rod surface looking like below (path of travel to the right): I\ I\ I\ I\ I\ I\ I\ I\ I\ I\ I\ I\ I/ I/ I/ I/ I/ I/ I/ I/ I/ I/ I/ I/
So I'm 12 days late. But I immediately noticed one thing. From what I've seen modern APFSDS round the penetrator has like a backwards groove to them. As others have commented, I assume this is do that the discarding portion of the round more so drags the penetrator along the barrel rather than the penetrator pushing the entire round down range. Might explain the fins reaching the target first before the main bit is even half way.
I would cast your sabot petals out of aluminum or use a plastic that is more malleable. HDPE might work if you can print it. I would even try plaster or cement, it just has to survive until the muzzle. The acceleration is too much for the plastic and it is shattering. The fin design you have looks good but I would at least sand cast it in aluminum or weld steel ones on. The aluminum casting would probably deform under the acceleration of the shot so might not be worth bothering with.
NO NO NO NO NO!!! Your fins are destroyed a picosecond after the charge goes off! Your plastic material, what ever it is, is destroyed before your steal penetrator ever gets into motion. The penetrator MUST be put in motion at the same time as the fins! Design your fins so that the penetrator slides through the fins from the bottom but are prevented from sliding through the the fins by a head on the back side of the penetrator, kind of like a head on a nail. The penetrator and the fins should come evenly in contact with the "wadding" that will push them down the barrel. I would design the sabot "wadding" more like a shotgun shell's wadding. The base needs to be rugged so it can get the mass of the penetrator and fins in motion with out being destroyed but with a cushion built in to absorb the shock of being put in motion. Make your "peddles" an integrated part of the base "wadding", again like a shotgun shell, so your projectile stays in one piece as you put it down the gun barrel. Only put a rubber band around the "peddles" to hold them together during shipping and remove it as the projectile is placed down the barrel. I want the "peddles" separating from the penetrator as soon as possible, right as it comes out of the barrel. The "peddles" will have to be ridged enough not to buckle as the projectile is put in motion so as not to interfere with the directional control of the fins. Good Luck.
There are detail images service rod munition and their sabot. Maybe copy one of their design. Your projectile is most likely way too heavy for your propellent. Maybe something like 40mm cta design, minus the slip ring as you are not dealing with rifled tube. I mean there are many research paper talks about sabot seperation.
Perhaps replace the fins with a threaded metal piece and make the rod thick with machined ridges to hold the sabot. The sabot needs to be stronger. Perhaps nylon, abs or phenolformalderhide. If you could find out what propellant is usually used for this type of shell in a tank, it may also help. The penetrater may need to be heavier than steel also. Not an expert but as an industrial chemist with some exposure to engineering my 2c worth. Have fun and be safe.
Extend the petals behind the fins, or just braze/weld on some metal fins. Military designs have gripping feature inside the petals that lock into the penetrator.
Looking at the video and applying common sense your fins are being shattered by the charge going off. When the charge goes off it's like hitting the projectile with a big ass hammer shattering the fins. If you extend the penetrator through the fins and add a steel push plate to the end of the penetrator to spread the shock load over a wider area you should have better luck. As I remember from photos the penetraters of the M1 Abrams rounds are 6 or 7 caliber long including the push plate.
@@TheCannoneer i dont know if you have ever seen paul harrell and his "meat target" but id love to see you shoot a "human like" object with grapeshot so we could get an understanding of how deadly these loads were
Looking at the video and applying common sense your fins are being shattered by the charge going off. When the charge goes off it's like hitting the projectile with a big ass hammer shattering the fins. If you extend the penetrator through the fins and add a steel push plate to the end of the penetrator to spread the shock load over a wider area you should have better luck. As I remember from photos the penetraters of the M1 Abrams rounds are 6 or 7 caliber long including the push plate.
If everything is rigid somethings probably going to fail. It's an old school cannon but its the exact same thing as a modern cannon, a controlled explosion. I would add a couple discs whose sole purpose in this life is to be crushed and absorb some of the shock from being fired, but not be blown to pieces so they can be pushed down the entire length of the barrel..kinda like a spring that compresses real quick but then never actually releases
The PLA fins are never going to stand up to pushing that rod out the barrel; extend the rod all the way to the pusher plate, make the pusher [wad] out of a more rigid material [nylon perhaps] than TPU and then attach the fins to the rod. If you use threaded rod, you can screw a nut on near the front that will provide a rigid drive interface for the discarding sabot, and all thread is common and cheap.
maybe try putting the fins slightly higher up ( by like a quarter inch) so that the force of powder burning isn't going directly into the easily damaged plastic. or use metal fins.
Your penitrator needs to be your pressure point. All your pressure is being forced onto the fins destroying them. Add a metal nail head and move the fins up the steel so the pucks make contact with metal. Your fins might be better machined which is probably outside of your vision.
Need to machine grooves further down the projectile to lock into the sabot, spreading the energy and mechanical stress evenly onto the projectile. Metal fins would work better too.
That baseplate disc is transferring the entire pressure load of the black powder charge to the fin assembly, and the damage is multiplied by the difference in weight between the fins and the metal penetrator. What I would do to redesign this is modify the baseplate and fin assy to where the baseplate disc can support the pressure load and transfer it directly to the penetrator rod, which seems to be the most difficult object to get up to speed quickly. The disc can be done away with entirely, however, if you cut a ribbed pattern into the penetrator rod and a matching one into the inside of the sabot so it can "grip" the sub-caliber round itself and so that the pressure load is dispersed into the sabot, which drags the penetrator and fins along with as it travels out of the barrel. You might also want to toy with the size of the powder charge. Too much powder means too high of a pressure spike, which means the sabot or baseplate disc would be more likely to shatter under the strain of such a sudden acceleration. I hope this advice is good enough to make a difference, preferably for the better.
Ramjet Engine style round would maybe have a chance of working at those speeds but it’s just an idea. Although there’s probably a reason they’re not already in use
Hey, it´s a great project but here is the thing, the pressure in the barrel goes through and around the Tpu wad, although it has a good seal, which causes the sabots to fly off the penetrator, which then can not be stabilized and just spins through the air. Also somewhere in the process, it shears off the fins. I would say try making the fins thicker and maybe try printing some ring that you can secure on the penetrator, that will ensure that the sabot does not fly off.
You have to support the main pin in the center. If you’re pushing the fins, you’re gonna push those fins off of that pin. If you have some thing pushing on the back end of that steel pin just as much as you have it pushing on those fins, you should get a better shot with your Round. Otherwise, you’re just pushing all the plastic past the steel rod and then the steel rod has no correction because the fins aren’t attached anymore. Try something supporting and shoving on the pin that is your penetrator as well as the fins.
Ditch the fins, use a solid cone 30-40 degree angle. Need to turn grooves into the shaft and have matching grooves in the petals. Lastly the front and rear petal supports need to be further apart to improve the stability
The fletching can not support of the penetrator. when you place the disk behind the the round, all the weight then is focused on the fins. Then fins get smashed in the 500G acceleration. The Sabot has to support the penetrators' mass during that rapid acceleration.
I think you should put some more thought and effort into this I mean right off the bat I can see what's going on You have a flaw in your design Just as you slide your pallet ring on your dart during shooting it gets ripped off ahead of the dart because nothing is holding it together Which is kinda obvious if you just this once on a paper My reccomendation would be making a custom dart with a step off on it and make pallets to hold onto it that way
The finned dart sabot rounds have been some of the most difficult things for me to get to work and I'm dealing with half the scale you are.
You can't put a wad behind the fins because that will just crush the fins. The sabots double as the gas seal. Most of the darts we have tested (CanaDart, Anferov bullet, Dynaslug, and Sauvestre) have lugs on the shaft that match up with lugs on the sabots. Almost all the pressure acts on the sabots and pulls the dart down the barrel as the dart is locked onto the sabots. A common failure was when we tried to push the rounds too hard - it stripped the lugs right off and the sabots went flying at a high speed and the dart followed along at a very low velocity. The video we just did with the CanaDarts used very brittle 3d printed parts. I had to use a small 25 grain charge of Pyrodex and a spoonful of coffee as an inert buffer to fill the space. They worked OK but we were only getting about 500 to 600 fps.
It's great to see you here, i love both channels !
Colab!
Oh snap! Wow! Thanks for tuning in! I just recently found your channel and subscribed and your sabot dart made me realize that the rods were supposed to be threaded(and why 🤣😂) like two days before this video came out. I’ve so appreciated the knowledge that you share on how to cushion rounds and the ways you load them and the gas seal ideas. I hope you truly know how much I appreciate your channel and I didn’t expect this to even make it anywhere near a comment from you! I will for sure take your tips into account and get a working V2 version in the future. I greatly appreciate the tips and you tuning in in the first place! Keep making those amazing videos.
@@TheCannoneer One of my viewers left a comment saying you were having trouble with your sabot darts so I had to check it out. The viewer-created projectiles have been fun to do and I've been surprised at the creative ideas people have sent. People have been telling me that we need to scale things up to something like you are doing so it is great that you are taking that opportunity. The 12ga. stuff keeps me busy.
@@taofledermaus I was checking out the back catalog and there's some seriously weird things folks come up with. I have a hard enough time making a big round lead ball half the time!
Your problem is simple, the sabot is supposed to lock on to the penetrator and is used to accelerate the penetrator down the barrel with the sabot releasing and flying free once the penetrator exits the barrel. Your base was is crushing the stabilizing fins upon ignition.
I will admit I didn’t know why the rods were threaded but that makes total sense…
This is the correct answer.
@@TheCannoneerThey are ribbed*
for her pleasure
I was hoping someone said this.
Grooved not threaded but yes. This.
"My name is Jonathan, this is my canon."
Your intro have no right to go this hard
🤣😂 thanks!
Never would have I imagined seeing an old canon, be fitted with an APFSDS round 😅
🤣😂🤣
I'm sure if you were able to look deep enough, some unit from the Confederacy probably at one time said " Hey, y'all watch this".
@@jaxonboys3366this made me laugh
ok, so here is my suggestion: Since you 3d printed the fins I think that you could/ might consider printing a hollow mold of those same fin designs for the rear portion and then using perhaps a resin filled with carbon fiber fibers mixed in and applied as evenly as you can. Perhaps a mold design that would snap together and allow excess material to flow out of tiny port holes that when cured could be cut or filed off. I would also be interested if you used the same method to cast a set of concrete fins and again allowing the discarding front portion of your sabot to simply be 3d printed out of the current materials. Only suggestions so please do not listen to me, but I think that it may work.
I think the molded fins are a good idea so I’ll have to figure out how to get that working or weld them on! I’ll probably make a few different versions from everyone’s suggestions!
Well I was in Armor.. The petals are only there to keep the penetrator center in the bore and nothing else, so try to leave the petals completely loose so they separate the instant they leave the bore.
We shall find out!
You should name the series of viewer submitted designs as "Send It"
I added your suggestion to the list and I’ll run a pole one of these days! I like it a bunch though!
It seems to me the PLA fins might shatter before leaving the breach, due to the base plate being slammed into the much more massive steel penetrator rod. Try metal fins? Or redesign the fins so the rod touches the plate, that way they won't be crushed between the rod and the plate on firing.
Metal fins for sure! Some folks have suggested TPU so we shall try both!
Me aswell as some of the discord from SIMULATION BROS will try to help you by putting together a design, i'm thinking of making a lugged sleeve for the sabot
Much much appreciated!!! Let me know if you guys need anything!
You should call it you make we create
Oh a real apfsds round they have prependicular grooves that the pedals fit into so they dont slide off, if its clear what i said😅 hope it helps
For sure!
I want that cannon so bad now lol
You should build one!
maybe you could try using a piece of threaded rod instead of a smooth one
For sure. Edit #1!
Your biggest problem right now is your APFSDS projectile is getting left behind by the sabots because there's nothing really holding them together. Real APFSDS rounds are held mechanically to the sabot by a series of machined grooves in the sabot and projectile locking them together. The sabot has the majority of the surface area and is where the majority of the "push" from the gunpowder goes and it pulls the APFSDS projectile down the barrel along with it. What might work best in your case is to make the metal rod go down to the base of the fins and have an additional base to push the projectile from behind. That way the majority of the force is the new base pushing on the rod from behind instead of trying to pull the rod from the front. You would have to redesign your sabot a little to make sure it could also hold up to getting pushed from behind, but that should be mostly making the rear section thicker.
You could also try printing your fins thicker and from Carbon Fiber TPU, which is significantly tougher against sudden shock and impacts while still being pretty stiff. It's pretty abrasive on brass nozzles so you would need to get at least a hardened steel nozzle.
I don’t know if I can print carbon fiber on my printers! I’ll have to look for sure! I was wondering what the all thread was about inside them but that makes complete sense. Keeps everything together.
@@TheCannoneer All you really need is a hardened steel nozzle for your printer(Short term) and hardened steel/replacement extruder gears(Long term) if yours are brass. If yours is a threaded removable nozzle it's almost certainly a standard size nozzle that's widely available anywhere that sells 3d printers and accessories. If its something more proprietary, like from Bambulabs, they usually sell hardened nozzles or may come standard on their high end models.
@@tu-jx6wh there are also tungsten carbide nozzles as well, they don't wear at all, they will basically last a lifetime unless you're extruding filament loaded with diamond powder, which I don't think exists...
The easiest answer for the rod is to make it from a threaded steel rod and have the three print sapo interact with that you could also easily machine a metal tip that you could then screw on to that rod
@@TheCannoneer Using a section of all-thread as your projectile might be a quick and dirty way for your sabot to retain the penetrator rod as it goes down the bore. Keep the sabot pulling by threading its inner section to match the rod.
Oh man, a collab between this channel and Kentucky Ballistics would be amazing
My name is Jonathan and welcome to the Kentucky ballistics range!
@@TheCannoneer you really need a collab with the channel morecannonfab
Taufladermaus did a video like last week shooting some flechette rounds. It seemed like the sabot fully encased the flechette and had a cup shape at the tip above the tip of the projectile so once it's out of the barrel it catches air and splits instantly. I feel like that would work well here.
I shall have to check his channel out some more. I didn’t even know he existed until recently when y’all started suggesting it and he’s got some many cool designs! Thanks for the tip!
@@TheCannoneer Some think his channel existed before UA-cam......
He did have the test tube torture tests (say that five times fast) before he went totally to the shotgun ballistics@@clangerbasher
@@davidjernigan8161 I was making a joke. Nothing more.
@@TheCannoneer I was going to suggest that channel but figured you knew. The 12ga designs would translate well to your barrel I bet.
The other comment re a concave cup leading the sabot parts sounds right on. Clean separation
1. Don't make pressure push on the fins with the pad
2. add grooves on the rod so the sabots have tight grip
3. Add aerodynamic surfaces on the front of sabots that will better push them apart after leaving barrel
- I really like your creativity 🙂
Sounds good and checks out
Much appreciated! I didn’t know these rounds were pushed by the sabot and not the fins when I made these but yall have wonderfully explained that so I was unknowingly putting pressure on the wrong parts. We will be a redesign and get these working! Thanks for the tips!
Here is an image of what Martin is talking about. I believe these sabots are normally split lengthwise into three pieces.
pbs.twimg.com/media/DmcwFhqVsAAGF3C.jpg
The sabot needs to pull the dart from the front. Not be pushed from the back. In all APDFS rounds from 7.62x51 DU to 120mm. The sabot pulls from the front.
It's also cupped at the front to catch the air and separate from the dart as quickly as possible after it leaves the barrel.
I'm sure people have mentioned the grooves normally found on darts so the sabot doesn't slip.
An interesting fact. Surplus 7.62x51mm DU has made it onto the civilian market. It's really rare but cool.
4. Keeping it subsonic also helps. Typical black powder shot is transonic -the worst possible speed for this purpose.
I've tested this kind of things with air rifles. Just a half gram piece of florists wire with rice paper vanes and a wood plug seal.
From a low power target rifle , ca. mach .4 speed, they work fine, consistently stick point first on 4" board at 10 paces.
From full power mach 1.2 vermin rifle they come out sideways.
On APFSDS, dart shaft's positive ribbed while Sabots' interior's negative ribbed so the sabot grips the dart shaft and doesn't blow out. Current construction is a soft "rubber gas check" then delicate plastic fins, then metal dart. On firing, the rubber and plastic fins probably give some or shatter. Maybe rag packing over powder then a short wood cylinder behind the dart as a rigid pressure bearing point. The solid shaft should carry all the way back to the bearing point - wood dowel -( the fins should end at the back of the dart). The sabots look sound, they only need center the dart, elastics alone should do. ..just a idea... besides, wood is cheap ! ..cheaper...
Good ideas! I was thinking about wooden darts and different materials if we got them working at all! Much appreciated for the improvement ideas!
@TheCannoneer Definitely check out how shotguns use a wad with a bit of spring-like material instead of a solid puck to push the round. It should help with the fins breaking on firing! Loved the video btw
@@charliegarrison9688 Thanks so much on both accounts!
Name the Segment “You Cannon not be serious”
I like it!
@@TheCannoneer try making HEAT-FS rounds next!
You're definitely crushing the fins.
Either metal fins or having the rod go right through to the back would be the quick and dirty solution.
Someone pointed out the TPU base is probably was just piercing a hole through and blowing everything apart in the barrel which makes total sense. I’ll have to revisit the metal fins idea and a few harder base plate materials….
Don't put wadding of any kind behind the fins, that's only going to load them and destroy them. Serrate the penetrator and have the sabot grip the serrations to pull it through. If spacing and a smaller charge doesn't help then you'll have to go with an all metal dart. Normally the fins are in the propellant explosion, they are NEVER pushed.
I had the idea of how these worked completly backwards when I put these together! Now I know why the threads are there. All thread on V2 for sure!
There's another guy on youtube called flasutie id hit him up and ask him for ideas since it's one of his specialties and he might be able to help i hope you get it to work and i can't wait for the next video.
Love that guy
I’ll check him out and see what we can make happen! Thanks!
Another channel worth checking out for ballistics is Taofledermaus. They’ve done some darts
taofledermaus is another good resource if you haven’t discovered him yet. He basically does the same thing just with 12 ga shotgun loads. There are several videos of “apfsds” rounds going through iterations to find what works. I imagine it would be a good resource since I think people have gotten them to work, though on a smaller scale with about the same acceleration. Idk how that scales to a small cannon though.
@@rofllcats I just recently found his channel since yall mentioned it! His loading techniques with the cork seems super handy and I will be sure watching more of his videos for some tips!
Thank you guys so much for all your wonderful ideas on how to improve this round! We will get this working in the future with all of your improvements. Thanks for your support!
This might sound like a war crime do you think you could fire glass shards? Would be interesting to see what it does to a melon.
Love seeing this pop up :)
For a muzzle loaded apfsds you need a flat bottom piece that goes behind the flechete and support the sabot extrude a rod enveloping the flechete 30% of it is the base or the piston this is a single piece the remaining 70% is the sabot and you cut it in 2,3or 4 parts from the top and the head need a cup or c shape to catch the air to peal apart
And attach a pvc tube to the reloading rod so it doesn’t touch the flechete only the sabot
Edit and use paper strips to hold it instead of ruber or tape
And I don’t know if it’s will be useful but I shot a “apds” on my air rifle using a mold to envelop half of a nail in compressed wet toilet paper it works well both as a single solid piece or as a solid base and 2 peals apart mid ,it’s shrink a little wen dried but you can umidify (don’t wet it again)before shooting
Two options for making the penetrator better. Either make the overall length of the penetrator shorter or the fins longer. That would help it as far as staying on the flight path
1) I'd try a different 3d printed material- I've used PETG sabot rounds in my muzzleloader, they don't seem to break up at all (less brittle)
2) I'd try a softer wad- maybe felt layered or t-shirts layered
3) That penetrator needs to be nose-heavy and tail-light. The first 1/4-1/3 of the penetrator should be lead or steel, the body should be composite, and the fins 3D printed
Love this channel dude, keep up the great work! I hope these suggestions make it to you!
They for sure did! I’ll be sure to give some of them a try in the revisit and we will get these working for sure! Much appreciated!
steel fins welded might help and mayby an aluminium bore sabot. Cool stuff.
I’ll have to figure out how to get those working made!
I dont think the 3D printed fins are going to hold up to the forces involved.
An alternative design would be a yo-yo style to generate the spin. Sounding rockets use a yoyo to despin, but a modified design could also spin up the projectile. There are two ways. The first design is simpler, you attach a wire to the Sabot petals and spool the wire around the projectile. As the petals are flung outwards, they unwrap from the projectile, spinning it up. The second way would be harder but more similar to rocket designs, you would need to have some small weights on the end of wires with a slight rotation already present, if the wires are winched inwards to bring the weights closer to the projectile, the moment of inertia will decrease and the projectile will exponentially increase in rotational speed to keep the angular momentum constant. Having the wires pass through holes in the projectile and anchored back to the cannon or the sabot could winch the wires inwards if done right, the other ends of the wires just having some weights attached to them. The best way to think of this second idea is a figure skater pulling their arms in to spin very fast, the same principle will apply to the sabot if you can pull mass inwards to the center of rotation somehow.
You could also just try to make something more aerodynamically stable. The idea of the fins, besides spin stabilization, is to put the center of drag behind the center of mass. Alternatively, if you were to cast lead onto the nose of the projectile, it would be nose heavy and much more stable. Lead is over 50% more dense than steel, and very easy to cast. Real APFSDS rounds use tungsten or depleted uranium for the penetrator because of the increased density.
Watermelon.
Beautiful.
I love to watch them mistify….
We now have "Taufladermaus" style content but with a Friggin' Cannon!! Sweet!!
Hopefully we get some weird rounds from some viewers too!
@@TheCannoneer If you want a shape that just WORKS, consider the "diabolo" air rifle pellet shape. It self stabilizes without spin.
@taofledermaus I printed one but I didn’t shoot it! I need to get some in lead and give them a shot one of these days too! Much appreciated!
This sounds like an AK-50 style project that will become the core of the channel and will be solved in like 10 years xD
Bring the base of the steel to the base of the fins... Don't allow the fins to be pushed along the rod.
That seems like the first thing that will help for sure!
Several people have made one suggestion of cupping the front flange as an air catch when it leaves the barrel the air will catch the fina pulling them away from the penetrator. But the biggest thing for stability is not using a pusher behind the penetrator. The sabot needs to pull the core out of the barrel. This is because without a perfectly balanced core any slight instability is amplified by the pusher. One of the easiest ways to get the sabot to lock in to the core is cut a small groove around the shaft of the penetrator. The with the sabot add a small lip on the inner diameter to fit into the groove.
OH YEAH
jsyk, real APFSDS rounds have ledges / steps on the penetrator that interface with some on the sabot, so the sabot actually drives the central projectile. here, the sabot may just slide off the penetrator during firing as there is no mechanical interface
I’ll have to take that into account and maybe use some all thread and the threads on the petals and see what happens!
@@TheCannoneer all thread is an ingenious solution. this solves your fin mounting porblem as well as the pedal to penetrator friction.
Coffee grounds are a good space filler for some of this stuff too
And they should be a soft shock absorber! Thanks!
I see good comments here. Mainly I would just make the discarding part of it a chunky cylinder that fills the bore and encapsulates the fins in addition to the penetrator to support everything as well as possible. 3D printing lends itself to chunky designs and your fins are too flimsy to be carrying all that acceleration by themselves. You might even see about adding a steel cross pin into the penetrator a little further up that can also key into the discarding sabot to take some of the stress off the fins. This would allow the sabot to pull directly on the penetrator taking some of the force away from the back. I imagine that even if the fins are surviving, the penetrator is getting driven back through the fins and through your TPU pushers like the penetrator that it is lol
Weld the fins on the rod.
I’ll have to see if I can get some steel ones!
For old school artillery, you need old school ammunition. Forget the 3D printed fins, just make a nice penetrator spike and fit it with a suitable discarding sabot. Bore a hole through the end of the spike and tie some hemp line with a monkey fist ball knot made a few thousandths shy of diameter of the barrel. Leave about 4 - 6 inches of line between the spike and the knot. Soak the line in water over night, this will keep it from combusting when fired. Ensure the monkey fist knot is still about the same size as the sabot outside diameter, dry it out a little if its swelled with water, coil the line to butt the knot up to the sabot then load the lot with a wad to keep the monkey fist off the powder. The ball should trail on the line when fired, inducing drag and stabilizing your penetrator. With some fine tuning on the size and weight of the rope ball, you should be successful.
If you look at the tank's APFSDS, it's the back "bulge/ring" of the sabot that seals the case and is pushed by expanding gases (the front one keeps penetrator straight). The fins are actually inside the propellant when loaded. I think in your case those TPU disks simply push through stripping fins, because the penetrator is not supported well enough. Maybe redesigning the sabot in a way that it is pushed directly (so the sealing bulge/ring is behind the fins), and adding on the inside something that would grip the penetrator along its length would help. Anyway - great video.
That makes total sense and when I found one of those discs it did have a hole in it. I bet you’re totally right as to what’s happening inside there. I didn’t realize how those rounds really worked until y’all explained it and that makes total sense. We’re pushing from the wrong part and the stress is on the wrong piece. Much appreciated for the tips!
@@TheCannoneer yeah apfsds is really cool in its simple science. my countoured fin base cap idea was more of a solution geared towards your current design layout. but if you actually redesign entirely and aim for the proper shell mechanics i think youll see much more success and much easier than trying to improve your current one.
As much as we love 3D printed projectiles, they have limits as far as surviving violent acceleration as you would see in a black powder cannon. It's not impossible, but requires additional design improvements to prevent the projectile from being obliterated to avoid the plastic from being destroyed during firing.
Oh snap! Thanks for tuning in! You guys have great videos too! I’m hoping to get a working version with some of the tips everyone here has been suggesting. I truly appreciate you guys checking us out! If you guys are up from some exploding cannonballs…. Hahaha.
The sabot of the round itself is suppossed to be exposed to the pressure gasses, not a baseplate behind the round.
the fins were clearly not strong enough to hold all the force.
The problem with your round is that the sabot will get launched out without the dart if you had no baseplate. To fix that you need grooves on the dart and the sabot so they get locked together while still in the barrel.
That makes complete sense when you look at the cross section. I’ve got to make it work the other way around… as it’s being pushed from behind on the fins now. I didn’t put that together until now. Thanks!
Plastic guides should be attached to a steel rod, the easiest way to do this is with the help of ribs around it, the parts should not be attached to each other and come off immediately after the projectiles exit the barrel, then about the metal bar itself, it does not represent anything, there is no armor-piercing cap, core, shell made of soft metal...
You might try TIG welding some steel fins onto your penetrators. You might need a jig to hold the fins in place wile you weld though, to keep the heat from warping them out of alignment.
early sabot projectiles used tapered sabots to act as a way of holding and pushing the projectile down the barrel
The sabot must be metal. Let me explain. If you look at the m1 abrams, the whole entire system doesn’t have any buffers between the shell and the casing. The sabot must also be metal if the projectile is metal, that way the cannon pressure wont make the projectile sheer off any metal holding the projectile in place. I recommend CNC aluminum, it should be strong enough, plus you can print it into whatever you want.
Edit: if not already, it should be properly held together on the inside. That way the projectile cant move forward or backward in the sabot, so then the sabot can cleanly release after the cannon fires and it has left the barrel.
Awesome video. 👏
Thank you so much for tuning in! I greatly appreciate it!
PLA is too brittle.
People's liberation army?😂
You need to create break groves and only have the thinnest pieces of material holding them together.
The tape & bands are flexible and do not break apart. You need to guide the break apart and weaken the material along those break up sections so the force of the wind is stronger and more than enough to break the material. You’d better off using a more brittle material like dried cardboard or very brittle plaster. You’re not using even close the power of a shot real sabots experience when fired so you need to compensate by using material that’s more brittle to get the proper break away affect you’re after
Failure is always a welcome option. Looking forward to the next set of tests.
I’d hoped y’all would still like to see the failure!
It seems like the main issue is the power of the Canon is pushing the fins of the Sabo through the shaft basically destroying the fins before it's even leaving the barrel to fix this it would be better for the shaft of the Sabo to go all the way through the fins
Theres alot of good information in the comments to recap the main changes that you need to make if you want this to work
1. you cannot pit wadding behind the fins bc the fins cannot be made strong enough to be load bearing and will be crushed by the wadding
2. In a normal sabot round the petals interlock with grooves on the projectile and the petals are responsible for pulling the projectile down the barrel and obturating the barrel (thus taking the load of the fragile fine)
Also a note on terminology, what you refer to as the "petals" the parts the hold the projectile are called the "sabot", and the part you refer to as the "sabot" is the projectile
OMG you actually did it, amazing! sad that they didn't work. maybe having metal fins welded to the penatrator would work? Also nice voice over and always great camera work. If you get the APFSDS rounds to work ill send you a nice bottle of Dutch liqueur!
I try to make sure I keep my promises! I’ve still got the flechettes lined up but I can’t shoot them at our normal ranges. Only one will let us and it’s an hour from my house so I don’t get there often but they will be one of these days. I’ll raise you a glass on the working video one of these days hopefully!
Hah! You beat me to it! I've been itching to turn some custom tank sabot penetrator rounds for one of my cannons.
Gotta be honest, I would really like to see some explosive rounds, but the risks to you and the cannon would probably be too high. Also probably very illegal…
Me too…. Me too…. I think we can make some that have the primer tips but I’ll have to see what we can get up to….
The problem is the sabot petals and fins are being shattered by the force of the blast, the obturation you are using is getting blasted around the fins and petals
Make the fins stronger, make the dart body do to the base, support the base with stronger obturator pads something that the dart metal won't penetrate.
The petals are normally mechanically connected to the dart body you could do this with a few pins sticking out about 5mm each side about 5 or 6 at one inch intervals midway down the dart body.
I’ve got a bunch to redesign! I didn’t know anything about these but we will get them working!
What's that canon legally speaking? Is it a destructive device? A curio? Not-a-firearm?
Technically it’s an “antique” and the reproductions, as long as they fall under the black powder, muzzleloading, non cased ammunition, the reproductions are classified the same. Very similar to the black powder rifles and you can make one or buy one online and have it shipped to your door no paperwork needed. Now the ammunition can be a DD if it’s explosive or if the cannon is breach loaded the ATF will come calling you. Good question!
Try extending the penetrator to the Base of the fins, so it is in contact with the wad, and can absorb the brunt of the "g" forces.
The fins are probably being compressed to failure.
I 100% agree. They just compressed into nothing sadly. :(
Dumb question: is that the typical size of a cannon used in say the revolutionary and or civil war? Thanks
No worries at all! As far as I can tell 3,6, and 9 pound cannons were the norm in the revolutionary war. Ones Our size would have been fielded but as an anti personal cannon at closer ranges than the big guns. As for the civil war they had all kinds of different sizes but 3” rifles guns and 12 pound smooth bores were their go to. I hope to get a 3”rifles gun if the channel gets big enough. Thanks for tuning in!
I'll go with what the others have mentioned, the finas will never support being the part receiving the force, the penetrator needs a way to lock it to the sabot while in the bore, abd the fins need to be a tougher material.
I’ll get them working one of these days!
Food for thought...
The APFSDS has grooves which lock it into the sabot. Maybe if you turned a few grooves into the rod, or use a peice of allthread, it may adhere better to the sabot.
Also, you need a pushing charge, not a forcing charge. Perhaps loading your cannon to the training load specs might change the pressure dynamic. 😉
And yes, pin the fins. They want for a mechanical connection to the rod.
I’ve realized that I’m trying to reengineer the design to be pushed from the base and not from the sides and y’all have wonderfully explained that to me which I much appreciate. I’ll pin the fins! If I’d have quite known how they are supposed to work I’d probably have done some rethinking!
I hope you manage to get the APFSDS running. Why don't you build your own cannon in the future ? Made from a super alloy, 2.5 inch wall thickness so you can use fast burning NC powder for extreme muzzle velocity. For the APFSDS rounds, heavy tungsten alloy would be better, maybe even with a carbide tip and a TICN coating. I would love to see that. No one on UA-cam has ever tried this and I think it would get you a million clicks👍
We actually built our current cannon but we didn’t have the channel in mind so we didn’t film it… I’ll have to make a new one at some point and film the process! Sadly cannons have to be black powder or they are considered destructive devices and then the ATF gets involved…
@@TheCannoneer I didn't know that cannons in the US have to be black powder or the ATF gets involved. I am from Europe. Good luck with your project
Try using a stabilizing cone instead of fins. Tank training ammunition is cone-stabilized rather than fin-stabilized. Without machining the penetrator to lock onto the sabot petals, that might be the most durability you can get out of this design. Also, ensure that your rear TPU disk ("wad"?) is applying pressure directly to the metal rod, and not the cone or fin stack. Mounting the cone or fins a bit forward of the base of the penetrator will help ensure that the bulk of the force is absorbed by the metal rod and not the printed part, which should leave aerodynamic forces after the round leaves the blast envelope as the only thing the printed part needs to withstand.
You’re not supporting the penetrator. When you fire the shot, the plastic/resin is way lighter than the steel, the plastic is accelerating faster than the steel thusly totally destroying the fins and sabot. It’s a physics problem. Just like no seatbelt on a crash test dummy in a 300 mph crash, the dummy goes flying(the sabot) car doesnt
isnt the main problem the weight of the projectile? because the point of APFSDS is to have big force in small area but your looks a bit light and maybe thats the problem? im just guessing but you should try heavier material or just APCR. (i understand that you try to replicate the APFSDS but for such a small cannon it doesnt even make much sense) but still pretty cool project!
I’ve got a bunch of changes to play around with and that might be one is to lose the fins! Thanks for tuning in!
@@TheCannoneer no problem mate!
You should get a Slow mo camera in the future to really see what is actually happening.
I’m putting aside some $$ for one!
I THINK i figured out the 2 key issues.
1.) The Dart itself, is Notched into the Sabots, And they "Pull" the Dart down the Bore.
2.) Nothing staying intact Because you 3D Printed everything. You cant put Plastic with Ballistic Pressures and Heat.
Imagine being a criminal and robbing a guy then he hits you with the apfsds
🤣😂🤣😂
You can’t use PLA and expect it to work, let alone the design- you should be using something with some flex like Carbon Fibre PETG, ABS or maybe TPU is best
I dont care about no laws
I made a tank cannon that shoots apfsds in my backyard
Become UNGOVERNABLE
I think you have two big problems, one of which is related to PLA being very brittle. There is no way that the PLA fins survived being pushed by the wad. One thing I would suggest is making fins out of sheet steel and either cutting fins and welding them to the rod or bending the sheet to make two find and spot welding in the middle (like mortar rounds).
The second problem was apparent when you pulled out the rod from the sabot. You shouldn't need the TPU wad, the seal should be provided by the petals and they should "pull" the rod along. You need to cut some interlocking surfaces on the rod so you can't pull it out of the petal.
So:
1- welded metal fins
2- grooves to fix the sabot
Or:
Dispense with the sabot, use the wad and weld front and back fins to keep the rod centered. If the wad is providing the seal, there's no need for sabots.
Hope this wall of text helped.
One of your problems is sabot drag. For this more is better as it provides the force that causes separation. Black powder is likely to give you little more than 1000ft/s. An MBT sabot round exits the barrel at more like 6000fy/s. IE 36 times more sabot drag. The front of the sabot is a higher drag design too.
I'm not sure what plastic you are using, but I would look into what you could use that can take the heat and pressure of the black powder. Sabot's are one piece, fin and dart. And they're all made of the most dense material available. (Tungsten, uranium, etc.)
Can you print a 38mm x 40mm plug with a short, centered protrusion the same diameter as the penetrator? Then print the fins with a center hole the same size so you can set the pin against the rod? This would direct the propellant's force somewhat more directly through the rigid centerline. Hopefully the plug will even out the force of the detonation on the round. Super interesting, folks are on to something with the material durability question. When you get this sussed build a HEAT round. 😉
This is a learning experience, and it's great fun watching your imagination.
There will be many suggestions, and the fun of it will be in watching which paths you choose.
But whichever path you choose, be sure to get married & have children.
a few things I see that can be improved: first APFSDS Penetrators and the Sabot have some sort of grooves that basically are supposed to do what you did at the end with the rubber band as well as giving the sabot enough friction the keep them on the penetrator before firing , second: you souldn't strip the sabot parts together to allow them to seperate easily after leaving the muzzle, and third: dont use that base plate at the back. you basically replace the actual sabot with that thing, which causes a lot of issues.
Probably it also would help to try a material with a slightly better durability like ABS instead of the PLA.
Both the penetrator and the sabot need to be threaded so that they grib each other (i.e. a matching interlocking thread), otherwise the sabot (which is trapping the gasses) will simply slide straight off and out ahead of the penetrator, transfering little to no forward momentum to it.
The first goal therefore is to make sure the sabot gribs the penetrator tight until it has left the barrel, where wind resistance (drag) then forces it to seperate from the penetrator.
I'd suggest trying with a thread that is slanted away from path of travel on the penetrator itself, also refered to as a buttress or sawtooth thread, so as to facilitate a smoother seperation of the sabot from the penetrator as soon as it leaves the barrel,. In other words imagine a penetrator rod surface looking like below (path of travel to the right):
I\ I\ I\ I\ I\ I\ I\ I\ I\ I\ I\ I\
I/ I/ I/ I/ I/ I/ I/ I/ I/ I/ I/ I/
So I'm 12 days late. But I immediately noticed one thing. From what I've seen modern APFSDS round the penetrator has like a backwards groove to them.
As others have commented, I assume this is do that the discarding portion of the round more so drags the penetrator along the barrel rather than the penetrator pushing the entire round down range.
Might explain the fins reaching the target first before the main bit is even half way.
Everybody above is saying it, your projectile is a little too fragile and too light.
Freakin' awesome though........
Thanks haha. We will get these working with all y’all’s suggestions!
@@TheCannoneer I am amazed by it all.
I would cast your sabot petals out of aluminum or use a plastic that is more malleable. HDPE might work if you can print it. I would even try plaster or cement, it just has to survive until the muzzle. The acceleration is too much for the plastic and it is shattering. The fin design you have looks good but I would at least sand cast it in aluminum or weld steel ones on. The aluminum casting would probably deform under the acceleration of the shot so might not be worth bothering with.
NO NO NO NO NO!!!
Your fins are destroyed a picosecond after the charge goes off! Your plastic material, what ever it is, is destroyed before your steal penetrator ever gets into motion. The penetrator MUST be put in motion at the same time as the fins! Design your fins so that the penetrator slides through the fins from the bottom but are prevented from sliding through the the fins by a head on the back side of the penetrator, kind of like a head on a nail. The penetrator and the fins should come evenly in contact with the "wadding" that will push them down the barrel. I would design the sabot "wadding" more like a shotgun shell's wadding. The base needs to be rugged so it can get the mass of the penetrator and fins in motion with out being destroyed but with a cushion built in to absorb the shock of being put in motion. Make your "peddles" an integrated part of the base "wadding", again like a shotgun shell, so your projectile stays in one piece as you put it down the gun barrel. Only put a rubber band around the "peddles" to hold them together during shipping and remove it as the projectile is placed down the barrel. I want the "peddles" separating from the penetrator as soon as possible, right as it comes out of the barrel. The "peddles" will have to be ridged enough not to buckle as the projectile is put in motion so as not to interfere with the directional control of the fins. Good Luck.
There are detail images service rod munition and their sabot. Maybe copy one of their design.
Your projectile is most likely way too heavy for your propellent.
Maybe something like 40mm cta design, minus the slip ring as you are not dealing with rifled tube. I mean there are many research paper talks about sabot seperation.
The petals should be discarding in exit from the barrel....trying to keep them attached is counter to what a SABOT is...
Perhaps replace the fins with a threaded metal piece and make the rod thick with machined ridges to hold the sabot. The sabot needs to be stronger. Perhaps nylon, abs or phenolformalderhide. If you could find out what propellant is usually used for this type of shell in a tank, it may also help. The penetrater may need to be heavier than steel also. Not an expert but as an industrial chemist with some exposure to engineering my 2c worth. Have fun and be safe.
Extend the petals behind the fins, or just braze/weld on some metal fins. Military designs have gripping feature inside the petals that lock into the penetrator.
Looking at the video and applying common sense your fins are being shattered by the charge going off.
When the charge goes off it's like hitting the projectile with a big ass hammer shattering the fins.
If you extend the penetrator through the fins and add a steel push plate to the end of the penetrator to spread the shock load over a wider area you should have better luck.
As I remember from photos the penetraters of the M1 Abrams rounds are 6 or 7 caliber long including the push plate.
you popped up on my homepage out of nowhere...
I see cannon.. i see big poof.. i watch.. i like.. me happy
Hahahaha! Much appreciated! If you have any ideas about stuff you’d like to see let us know!
@@TheCannoneer i dont know if you have ever seen paul harrell and his "meat target" but id love to see you shoot a "human like" object with grapeshot so we could get an understanding of how deadly these loads were
Looking at the video and applying common sense your fins are being shattered by the charge going off.
When the charge goes off it's like hitting the projectile with a big ass hammer shattering the fins.
If you extend the penetrator through the fins and add a steel push plate to the end of the penetrator to spread the shock load over a wider area you should have better luck.
As I remember from photos the penetraters of the M1 Abrams rounds are 6 or 7 caliber long including the push plate.
If everything is rigid somethings probably going to fail. It's an old school cannon but its the exact same thing as a modern cannon, a controlled explosion. I would add a couple discs whose sole purpose in this life is to be crushed and absorb some of the shock from being fired, but not be blown to pieces so they can be pushed down the entire length of the barrel..kinda like a spring that compresses real quick but then never actually releases
The PLA fins are never going to stand up to pushing that rod out the barrel; extend the rod all the way to the pusher plate, make the pusher [wad] out of a more rigid material [nylon perhaps] than TPU and then attach the fins to the rod. If you use threaded rod, you can screw a nut on near the front that will provide a rigid drive interface for the discarding sabot, and all thread is common and cheap.
maybe try putting the fins slightly higher up ( by like a quarter inch) so that the force of powder burning isn't going directly into the easily damaged plastic. or use metal fins.
Your penitrator needs to be your pressure point. All your pressure is being forced onto the fins destroying them. Add a metal nail head and move the fins up the steel so the pucks make contact with metal. Your fins might be better machined which is probably outside of your vision.
Need to machine grooves further down the projectile to lock into the sabot, spreading the energy and mechanical stress evenly onto the projectile. Metal fins would work better too.
That baseplate disc is transferring the entire pressure load of the black powder charge to the fin assembly, and the damage is multiplied by the difference in weight between the fins and the metal penetrator. What I would do to redesign this is modify the baseplate and fin assy to where the baseplate disc can support the pressure load and transfer it directly to the penetrator rod, which seems to be the most difficult object to get up to speed quickly. The disc can be done away with entirely, however, if you cut a ribbed pattern into the penetrator rod and a matching one into the inside of the sabot so it can "grip" the sub-caliber round itself and so that the pressure load is dispersed into the sabot, which drags the penetrator and fins along with as it travels out of the barrel. You might also want to toy with the size of the powder charge. Too much powder means too high of a pressure spike, which means the sabot or baseplate disc would be more likely to shatter under the strain of such a sudden acceleration. I hope this advice is good enough to make a difference, preferably for the better.
Ramjet Engine style round would maybe have a chance of working at those speeds but it’s just an idea. Although there’s probably a reason they’re not already in use
Hey, it´s a great project but here is the thing, the pressure in the barrel goes through and around the Tpu wad, although it has a good seal, which causes the sabots to fly off the penetrator, which then can not be stabilized and just spins through the air. Also somewhere in the process, it shears off the fins. I would say try making the fins thicker and maybe try printing some ring that you can secure on the penetrator, that will ensure that the sabot does not fly off.
You have to support the main pin in the center. If you’re pushing the fins, you’re gonna push those fins off of that pin. If you have some thing pushing on the back end of that steel pin just as much as you have it pushing on those fins, you should get a better shot with your Round. Otherwise, you’re just pushing all the plastic past the steel rod and then the steel rod has no correction because the fins aren’t attached anymore. Try something supporting and shoving on the pin that is your penetrator as well as the fins.
Ditch the fins, use a solid cone 30-40 degree angle. Need to turn grooves into the shaft and have matching grooves in the petals. Lastly the front and rear petal supports need to be further apart to improve the stability
The fletching can not support of the penetrator. when you place the disk behind the the round, all the weight then is focused on the fins. Then fins get smashed in the 500G acceleration. The Sabot has to support the penetrators' mass during that rapid acceleration.
I think you should put some more thought and effort into this
I mean right off the bat I can see what's going on
You have a flaw in your design
Just as you slide your pallet ring on your dart during shooting it gets ripped off ahead of the dart because nothing is holding it together
Which is kinda obvious if you just this once on a paper
My reccomendation would be making a custom dart with a step off on it and make pallets to hold onto it that way
Easy fix, make the projectile out of metal instead of plastic. Shooting plastic with an explosive is clearly ganna shatter the plastic
Make back side (feathers) from metal same and that's it!!! Simple!!!😊 Greetings from Serbia 🇷🇸!!!😊
Welded fins for sure on V2! Thanks for tuning in! I see your country a lot UA-cam thanks to Zastava arms and its beautiful from what I can see!
Simple guess, 'hide' the fins in the discarding part and make it so that the wadding pushes on the exterior of the round, not the final projectile.