I used to work for Rocketdyne in the 60’s where we made the attitude control thrusters 25, 75, and 100 pounders. We made them out Ablative material with a Graphit throat. In those days we used tracer lathes. Those were the days.
Great video. I worked in a graphite shop for 16 years turning graphite on both CNC and manual lathes. And NEVER once wore a respirator or even a dust mask. I'm 62 now with no respiratory problems at all and all the dozen or so guys I worked with have had no problems. Not saying it was smart (definitely not smart) an ounce of prevention worth a pound of cure. I so enjoyed the video this is great tv please keep it up.
Bernoulli's genius can only be matched by Newton and his famous description of the 3rd Law of Motion: "Alright, so check this out bro; It's like, for every action there's a freakin' equal and opposite reaction, dude! So, like, if you pushin' sumthin', it's gonna push back just as hard. For real, bruh...no cappin" Isaac Newton, 1687
Add in Charles, Hook, Boyle… they were all contemporaries, regularly spoke to each other, and most of them were founders of the Royal Society. Oh, and with the exception of chemistry, invented all the science you learned up until university out of whole cloth in a single 30 year period. Scary smart dudes. At least as smart as Einstein’s clade.
Joe, your work and videos are great! Keep it up and I can’t wait for the next one! When you had the lathe outside I imagined what was being said at neighbor’s house, “ I’m bored. I think I’ll look out the window and see what Joe is up to and what kind of costume he’s wearing today”.
Nicely done! While "ring of bolts" is popular among amateur motor makers, I always preferred internal snap rings. Might not work in your case, though. Also, I think I've mentioned before that using a *cheaper* graphite grade (the extruded stuff) will often result in a nozzle that is less prone to thermal shock on start-up. I learned this the hard way. Bought the highest-density iso-moulded graphite I could afford, turned some gorgeous nozzles. They all popped at start-up. Did the same profile in extruded grade, and that problem went away. The more you know...
hydraulics can leak down over time, so you'll have to babysit it and monitor the pressure My suggestion would be to just find an old arbor press that's large enough to fit most of this stuff, mount it on a heavy bench that will allow the passthrough to reach the ground, and then you can either put things that fit on the bench, or larger things under the bench for clamping. to clamp with an arbor press, you just hang a weight on the lever arm. it's a mechanical press that will get you enough push to get friction fit parts together without going overboard
"The worst of both worlds, a hybrid." Those of use who work with hybrids like to think we enjoy the challenge. :) Excellent video. I will definitely be making this part of our high school rocket engineering curriculum. FYI we build hybrids. Thank you for your content and your passion.
Love your content man. Just a machinist here giving you a potential tip. If you need to turn something bigger on your lathe you can try using a boring bar upside down and running the machine in reverse. I had to do it a few times at work because it was at the machine's capacity lol. We actually had to modify the guards on the lathe to fit the part in.
Also as a machinist, all the things he claims are "stupid" are perfectly normal machining shenanigans. Figuring out how to hold weird shaped things that are just slightly too big for your equipment is what separates actual machinists from mere CNC-Go-Button-Pressers.
As the primary machinist on my school's robotics team, I can relate to lathe troubles. The lathes we use are literally WWII surplus (or came with the school when it was built in the 50s), with the original leather drive belts. This is compounded by the fact that all our drill bits are pretty dull, which makes for a wonderful combination
im not asking to turn this channel into a machining channel, but can you show more machining? its very entertaining to see you machine parts outside in the nice weather. awesome video.
Great video series, it takes me back to the 1960s when a kid couldn't buy an Estes rocket engine in california... without an adult, a stack of paper work and a sign off by the local fire department chief. Firing them was a whole 'nuther layer of misery... Yes we made our own; yes I do have all my digits.
I remember the hazzle also! But we had a science teacher that in the 5th and 6th grade we would have rocket launches once a month! He taught us Trigonometry so we would have highest rocket launch. With a wooden triangle with a screw eye on top and bottom of one dide of triangle, and a protactor on the bottom with a sharpen popscile stick we'd sight the smoke trail and when it reached apogee we'd press the popscile stick and write down that angle. With that and the lenght from the rocket pad we'd get height of rocket! I knew trig in the fifth grade. School launches didnt need all the required permission. I didnt get it on my private launches at the park. But I do remembet reading the ruled. Thanks for reminding me of it. I was in elementry school in the 60's also. A great science teacher for sure. Mr Smith from Cloverland Elementry in Oakdale Cailf. Good times.
Pro tip from a tool room worker when turning larger stock than your lathe can handle. Use a boring bar from the back side of the part turning backwards. Also makes chamfers and tapers on external flanges easier.
I get using equipment outside. Pro tip: high velocity fan. Scorching summer heat = not a problem when there's a constant 15mph breeze blowing across you. Bugs can't fight it, heat no longer matters, plenty of light for whatever you're working on. Unbeatable.
Having followed along for a long while I find that what I enjoy most about these latest videos on the process you are developing.... Is You having a blast in the videos! 😊 It's great to see that side of development too since so much of your other videos have me biting my nails and sitting on the edge of my seat. Thank you for doing this. It's great to see your constant progression and that you remember to have some fun too 🎉
Little tip for the cross slide on the lathe, you can 3d print a drill attachment and get a smooth surface finish with minimal sanding. Try it out next time!
i am making a bioprepellant pressure fed rocket, and i also just picked some numbers: 30 degrees entry angle, 15 exit angle, 6mm throat. Chatgpt also helped me :)
Graphite isn’t abrasive; it’s actually used as a lubricant in numerous mechanical appliances. When I worked for a company that specialized in injection molding tools, I would just smother the graphite on the guiding pins of the machines. I have to tell you, it works like a charm, often better than grease even. There are also spring-loaded brass bolts that have graphite pressed into them. When there’s mechanical stress, the housing is abraded and releases the graphite for lubrication. But you're right, it's really messy and can pose a threat to certain types of electronics. And it's impossible to get your shop clean afterwards :D
Graphite is a lubricant and an abrasive. Turns out they aren't mutually exclusive properties. The key is the shape and orientation of the graphite particles. It's like a bunch of little pancakes. When they slide across surface to surface, it greatly reduces friction. When the edge slides across the surface of your material, it creates a little scratch, abrading it. But wait, graphite has a hardness of 1-2, so how can it abrade harder materials? Well, graphite is so soft because of how easily the layers break apart. Get down to a single layer and it has the same hardness as other crystalline allotropes of carbon (think diamonds).
Hey I’m a machinst when you’re boring you can rough out with big cuts .03” depending on chatter from your boring bar but once you get down to final cuts slow is smooth .001-.004” but this is assuming your lathe has enough rigidity to stay accurate. Also a machinist handbook will tell you your slip and press fit sizes (among every other thing on earth) which can help avoid tolerance issues as you know exactly what you need. A tight concentric bore gives you more accuracy this inherent efficiency
If you’re going to keep making more of these you can get a concrete boring drill which is a hole saw that is deep enough to cut 6” deep or more. You can also use isopropyl alcohol to lubricate the o-rings and leave no residue. It doesn’t damage viton or most other common materials.
If this were an 80's concert in a backroom of a crappy oyster bar, I would be the older guy with a mullet screaming "More, we want MORE!!!" TLDR I like these videos. 😃
If you use an 85 degree chamfer the inner edge of the rocket casing, it might be easier to insert the o-rings and nozzle carrier without nicking the o-rings. In addition, I couldn’t tell if you were using lube. Parker makes a silicon lube I have had good results with. Glycerin is another good possibility as long as your materials are compatible.
Machiniste trick, if you want to archive high tolerance, leave a little bit of material ( 0.001" or 0.002" ) and do the rest with sand paper ( turn your piece with the lathe and apply pressure with the sand paper), start with 80 grit and move to 120 grit. That way you can archive a good tolerance.
They make cnc China mini lathe replamcnet motors with ball threads too for under 40 bucks 10 years ago last time I could afford mini lathes. Buy alot of it is rigidity m that said if the lathe is anythkjt at all should hlbe able to adjust/replace the ways bearing pads. The factory ones are horrible hell again ack 2hen I coild sfford it my mini mill the collet tool holder was 8mm out of round from enter had a rig fab shop lathe it straight for me so I could make swarf ASAP 🤣 Looks like the way adjustment screwed are way too tigjt they take very precise and tedious fiddling to get just right but should end up butter smooth and be able to be turned with just 2 fingers and no backlash
From the book Solid Rocket Motor Design, the convergence half angle is chosen between 30-60, if too big it will cause a lost in thrust, if too small then the nozzle will be too long, 45 degree is usually chosen. The optimum divergence half angle is 15 degree, to shorten the diverging section , it is best to be chosen 18 degree. Just as a reference for people who want to design solid motors.
🙃 explanations @1:22 - @1:42 . Pressure begins to drop at @2:10 where and when velocity of gases begins to exit the previous high pressure area which is where the gases hit mach 1+ . A fun thing happens when a high pressure gas is given a tiny exit ➡➡ Because the exit is small at the entrance to the exit the pressure is still high but once the gases begin to leave their velocity jumps way up and the pressure at that point on drops to lower pressure. I understand you understand what is happening but sometimes the explanations are a bit twisted from what is actually happening. 👏👏 If there was not a reduction in the exit vs the diameter of the area where the high pressure gas was at to begin with then there would be no drop in pressure and no high velocity thrust because all the gas would get dumped out the back in mere moments without a high velocity thrust . It is the ratio difference from high pressure to low pressure that enables the velocity thrust we all seek and that special mojo is done via the exits size vs motor/gas area😘. There now I feel better. #Cheerios 🤣😇👊 #Whispers btw its not space its heaven🙏. 🤭🤫. . . 👉🧠👈
G'day Joe. For fitting your nozzle carrier with O rings installed into a liner. You might consider using a tool called a 'ring compressor'. Although the device is primarily intended for inserting piston and ring assemblies into the cylinders/liners of big diesel engines it might meet your needs too.
For getting smoother tapers with the compound, of you put both small handles back on rhe wheel (looks like they were removed), you can chuck the base of a T-shaped piece of metal into a drill, and use that to turn the handles. As long as you have the drill in low gear and keep thr speed fairly consistent, it should work better and give a more consistent surface finish than turning the knob by hand.
Been watching for years. Amazing to see how far you've come and how driven you've remained through the failures and successes. Also, very impressive how far you've come in engineering especially since I believe you got your degree in music, right? Anyways, I know you'll go on to accomplish great things. Keep the vids coming!!
Just finished my phenolic graphite nozzel that will go into my 4in carbon fibre composite motor, Kno3 srb fuel. Might see you in the Mojave desert one day.🚀🙂
A small press would help with your nozzle assembly (no dancing required)...a taller press would help installing the o-ring parts. I never thought about all the uses of a press until I spent time with a friend of mine with a really nice shop--he constantly uses his...basically a frame with cross tables and a bottle jack.
We needed long hole saws at my shop and what we did was weld a piece of steel pipe into a cut in half holesaw, worked perfectly. You could do that for the phenolic insulation
Suggest getting an arbor press. Small 1/2 ton, and a larger 3-5 ton. Probably the most usefull tool in the shop. Saves dancing on top of critical one-off parts.
Your nozzle angles are within reason. One thing to consider is a smaller divergent angle reduces cosine losses, aka some of the thrust being wasted going somewhat sideways out of the nozzle and not pushing the rocket up. By lower I mean something like 10 degrees vs your 15. Although a lower angle means a longer nozzle, and thus more weight, so it’s a trade off.
0:48 "A rocket motor that is solid, liquid, or-the worst of both worlds-hybrid..." Wow that's so offensive to hybrid motors (I 100% agree with this statement)
Suggestion: for future grain packing, 1, when you think you have all of your propellant in there, place a weight [or springs, or air pressure in a cylinder] on it with some packing material [such as beeswax or modeling clay in a ramming tube, and then 2, put a vibrator or ultrasonic horn under it to ensure all of the bubbles expel while none of the propellant fluffs, spalls, climbs, creeps or ripples. All of that would be using a fitted removable sleeve, something like PVC pipe is fine for this, and its cheap, and can be resized with heat if it is not a perfect fit. Be sure to clamp it though, so even if its a perfect fit, the pressure does not squeeze anything out, or pop the sleeve off. This should only take between 30 and 60 minutes but it should really clean out all of the voids. What will happen if there is entrapped gas is, just like with concrete, it will work its way to the top and exit. Since the clay [most modeling clay is actually quite light, but beeswax is much lighter if you can get it, say like off the internet] is somewhat lighter than the propellant it will continue to float on the top but the bubbles will float through it. I suppose you could mix up some flour and water into a sort of a dough, but it could have too many elasticity issues and make it impossible for bubbles to pass through it, or, on the other hand, you could use wet or dry sand, but then sand is kinda heavy and would certainly mingle and embed in the propellant, unless you had an excess of propellant with the intended goal of just cutting off the excess as waste, so that would be a decision to be made at that time. Honestly, either way, it would be good to have maybe an inch or two of extra propellant on top of the mold anyhow, because when the bubbles escape, you want to refill that void with propellant, not packing material.
Oh boy! You are making history here! As usual your videos are very detailed and at same time direct to the point! Please keep doing this amazing work! You "rocket"!!!
Watching these videos in public places (like I have any freaking idea what is going on) is my new favourite hobby. I’ve secretly never felt so intellectually inadequate in all my life; but that doesn’t stop me from enjoying following the story! 🚀
11:30 I can’t help worrying about the O rings getting damaged by the way that you brute-forced the nozzle carrier into the motor casing. Have you thought about using the same type of tool that car mechanics use when they install the pistons into the engine block? It’s called a piston ring compressor, and I believe that using something similar, could greatly reduce the risk of damaging your O-rings. (And make the install a lot easier.) Cheers from Vejle, Denmark 🇩🇰
Good to see you both back. I too play with all different kinds of electronics. At the moment the TomTom 550 is on but just got a mount to fit the bmw navigator fitting.
"Tolerance errors can stack up." I have a picture somewhere that demonstrates this really well. Steel lattice tower welding jig was off very slightly. For an individual 3m section, you couldn't see anything wrong, but getting the pieces to mate was somewhat difficult. Once it was stacked to 100m? You could look up the leg and see the entire structure was twisted. Ended up being something like $150k insurance claim to cover the labor of dismantling the structure and putting in a new one.
Dude you are such a legend. Have you thought about sharing your knowledge and process of iteration with students? You will without doubt inspire even more minds.
Have you tried wet pouring your mix into the casing, tooling installed, pull the vacuum on the pre-cast material that’s already in the case. Maintain the vacuum through the cure and then remove the tooling. No voids, perfect cast, tooling form is removed and you have a near perfect motor casting ready to shit and git.
Attach a cordless drill to the lathe carriage. You'll be able to move it smoother and easier on your hand after a while. Wouldnt nessecarily reccomend it for metals, but softer materials will work fine.
You might have seen or heard of them before, but you should look into getting some form taps/roll taps! They take some time to get familiar with and require somewhat specific drill sizes for your target thread form % (between 65-75% is where I've been getting fast reliable results), but you can look up the ideal drill diameter on a form tap chart as a starting point and then order a few sizes +/- the nominal drill diameter to dial things in for specific applications. I find if I'm cnc or drill-press drilling, the "correct" diameter typically works best, but for a hand-drilled hole, going slightly undersized seems to help account for inaccuracies from hand holding the drill which typically results in oversized holes compared to being drilled perfectly rigid and square to the surface as with a cnc/drillpress. With the optimal drill diameter figured out, I find that I can run m3 to m6 form taps with a hand drill and knock them out in quick succession(...but maybe don't try this immediately, getting familiar with the feel of the form tap going in is important too). These taps also have some unique benefits/tricks/quirks, the first of which I think would save you some headache with your nozzle carrier: - No chips to clear! It's a huge time saver. Depending on your lubricant/material, you may occasionally have to clean away finely powdered debris which builds up in the relief slot. Isopropyl alcohol as a lubricant for aluminum is amazing - not sure on specifically why, but it lubricates aluminum extremely well and also washes away any fine debris between holes with no oily residue to clean up afterwards. - The threads are typically stronger due to being cold formed rather than cut into the material. (ymmv depending on material and the depth of the hole though, brass is a nightmare in my experience lol, and I'm sure there are other materials which don't like being cold formed) - Form taps can last an extremely long time compared to cutting taps, assuming you don't snap them first or run them through undersized holes and gall material to them. 😂 - You can get "extra" threads from an open bottom form-tapped hole which can be used to your advantage. By using a slightly undersized drill diameter on thinner stock materials, when you run the tap, the threads bulge down/out as the tap exits which gives the fastener a bit more thread length to engage with. This can be problematic if you're tapping a tube wall where an internal and removable slip fit might be required. If you tap both the tube and the part within, it can also effectively lock that internal part in place with the displaced material. You could use this to your advantage though for extra part retention force too, it all depends on how you use it. Conversely if the material is too thin and too soft, then you might not get any threads at all as it might not have enough resistance against the tap, and just moves aside entirely as the tap slides through. If you do decide to try form tapping, I find that the polished/uncoated taps from Mcmaster work best with aluminum/isopropyl for every day applications. The TiN or TiAlN coatings can get 'sticky' with aluminum, and that's just a recipe for disaster with a form tap. For harder materials, Loctite LB8012 moly-paste works great with the polished/uncoated taps as well. I've tapped both titanium and stainless steel with that combo and the threads came out really nice. Hope some of this is useful info! Excited for the next video in this series! -Mike
You might think about making a piece with a conical inside bore to help you slide the cap with o-rings into the case, rather than risking pinching and compromising an o-ring. IC engine builders use them to compress piston rings during insertion of the pistons into the bores of the block.
Regarding the phenolic, why not build a jig with a bandsaw to get it round first? You're going to bore the center out of it anyway. You could drill a 5mm hole in the middle of one face, and pivot it around that on the saw. then turn it as normal on the lathe? This is how Frank Howarth does big bowl blanks in his woodshop.
Damn, I'm a turner by trade and it's still seriously impressive how far you're taking that little lathe. It's a shame I'm in the UK, or I'd happily turn some parts for you on my cnc if you needed it
Man i know nothing about rockets and i don't want to know either but for a long time i watch your video's and i laugh my ass off and i have immensely respect for your skills and ...humor ... a fan from The Netherlands ... keep it up and good sailing!!
5:45 "machining outside is a beautiful peaceful experience" said no neighbor ever
😂😂
🤭🤭🤭🤭🤭
This dust is really, really dangerous. So i'm doing it outside so everyone can feel how dangerous it is.
I think between this and his parachute tests their used to it by now
@@O5MO It's just graphite, not dangerous to the environment but definitely dangerous to your lungs in large quantities.
I used to work for Rocketdyne in the 60’s where we made the attitude control thrusters 25, 75, and 100 pounders. We made them out Ablative material with a Graphit throat. In those days we used tracer lathes. Those were the days.
To be able to work at Rocketdyne in the 60s, literally putting men on the moon. Definitely seems like one of the most rewarding jobs in history!
How old are you mr.?
@@leonardoraz6375 at least 85 I guess
@@leonardoraz6375 84 I went to work at Rocketdyne in 1963
Legend! Thank you for your work, sir.
This video is beautifully shot. Impressive work! Rockets are cool.
Thanks Destin!
No way smarter every day is here!!!!!!!!
@@BPSspace hey can you send me all the 3d models associated with simplex
script: "with a ton of clamping force" scene: 4 quickgrips trying their best.
Great video. I worked in a graphite shop for 16 years turning graphite on both CNC and manual lathes. And NEVER once wore a respirator or even a dust mask. I'm 62 now with no respiratory problems at all and all the dozen or so guys I worked with have had no problems. Not saying it was smart (definitely not smart) an ounce of prevention worth a pound of cure. I so enjoyed the video this is great tv please keep it up.
Love this format, shorter but more videos. Keeping in the errors is really a great way to teach too. Keep up the excellent work.
This is my new favorite series. Such great quality production and info from a passionate presenter. Thank you for your channe! I love it.
Buy a larger lathe, your time is valuable, you won't regret the upgrade. A Shars style quick change tool post is well worth the additional cost.
Bernoulli's genius can only be matched by Newton and his famous description of the 3rd Law of Motion:
"Alright, so check this out bro; It's like, for every action there's a freakin' equal and opposite reaction, dude! So, like, if you pushin' sumthin', it's gonna push back just as hard. For real, bruh...no cappin"
Isaac Newton, 1687
Add in Charles, Hook, Boyle… they were all contemporaries, regularly spoke to each other, and most of them were founders of the Royal Society. Oh, and with the exception of chemistry, invented all the science you learned up until university out of whole cloth in a single 30 year period. Scary smart dudes. At least as smart as Einstein’s clade.
Joe, your work and videos are great! Keep it up and I can’t wait for the next one! When you had the lathe outside I imagined what was being said at neighbor’s house, “ I’m bored. I think I’ll look out the window and see what Joe is up to and what kind of costume he’s wearing today”.
I'm really just here to put on a show for my neighbors :)
Nicely done! While "ring of bolts" is popular among amateur motor makers, I always preferred internal snap rings. Might not work in your case, though. Also, I think I've mentioned before that using a *cheaper* graphite grade (the extruded stuff) will often result in a nozzle that is less prone to thermal shock on start-up. I learned this the hard way. Bought the highest-density iso-moulded graphite I could afford, turned some gorgeous nozzles. They all popped at start-up. Did the same profile in extruded grade, and that problem went away. The more you know...
What diameter nozzles?
@@chrisnorth3458 various. Including 75mm and 100mm
13:25, I think, you need a hydraulic press in the shop 🙂
Harbour Freight sells: "12 ton H-Frame Floor Shop Press" for $170 (Instore Only, must be heavy to ship)
hydraulics can leak down over time, so you'll have to babysit it and monitor the pressure
My suggestion would be to just find an old arbor press that's large enough to fit most of this stuff, mount it on a heavy bench that will allow the passthrough to reach the ground, and then you can either put things that fit on the bench, or larger things under the bench for clamping. to clamp with an arbor press, you just hang a weight on the lever arm. it's a mechanical press that will get you enough push to get friction fit parts together without going overboard
Awesome, thank you for all the work you put into this series
Indeed, thank you!
"The worst of both worlds, a hybrid."
Those of use who work with hybrids like to think we enjoy the challenge. :)
Excellent video. I will definitely be making this part of our high school rocket engineering curriculum. FYI we build hybrids. Thank you for your content and your passion.
Love your content man. Just a machinist here giving you a potential tip. If you need to turn something bigger on your lathe you can try using a boring bar upside down and running the machine in reverse. I had to do it a few times at work because it was at the machine's capacity lol. We actually had to modify the guards on the lathe to fit the part in.
As a machinist i appreciate your machine struggles. Good looking work, I've made worse looking nozzles with nicer machines!
Also as a machinist, all the things he claims are "stupid" are perfectly normal machining shenanigans. Figuring out how to hold weird shaped things that are just slightly too big for your equipment is what separates actual machinists from mere CNC-Go-Button-Pressers.
As the primary machinist on my school's robotics team, I can relate to lathe troubles. The lathes we use are literally WWII surplus (or came with the school when it was built in the 50s), with the original leather drive belts. This is compounded by the fact that all our drill bits are pretty dull, which makes for a wonderful combination
im not asking to turn this channel into a machining channel, but can you show more machining? its very entertaining to see you machine parts outside in the nice weather. awesome video.
Great video series, it takes me back to the 1960s when a kid couldn't buy an Estes rocket engine in california... without an adult, a stack of paper work and a sign off by the local fire department chief. Firing them was a whole 'nuther layer of misery...
Yes we made our own; yes I do have all my digits.
I remember the hazzle also! But we had a science teacher that in the 5th and 6th grade we would have rocket launches once a month! He taught us Trigonometry so we would have highest rocket launch. With a wooden triangle with a screw eye on top and bottom of one dide of triangle, and a protactor on the bottom with a sharpen popscile stick we'd sight the smoke trail and when it reached apogee we'd press the popscile stick and write down that angle. With that and the lenght from the rocket pad we'd get height of rocket! I knew trig in the fifth grade. School launches didnt need all the required permission. I didnt get it on my private launches at the park. But I do remembet reading the ruled. Thanks for reminding me of it. I was in elementry school in the 60's also. A great science teacher for sure. Mr Smith from Cloverland Elementry in Oakdale Cailf. Good times.
Pro tip from a tool room worker when turning larger stock than your lathe can handle. Use a boring bar from the back side of the part turning backwards. Also makes chamfers and tapers on external flanges easier.
I get using equipment outside. Pro tip: high velocity fan. Scorching summer heat = not a problem when there's a constant 15mph breeze blowing across you. Bugs can't fight it, heat no longer matters, plenty of light for whatever you're working on. Unbeatable.
I love the characteristics of your method of picking nozzle geometry! :D
Having followed along for a long while I find that what I enjoy most about these latest videos on the process you are developing.... Is You having a blast in the videos! 😊
It's great to see that side of development too since so much of your other videos have me biting my nails and sitting on the edge of my seat. Thank you for doing this. It's great to see your constant progression and that you remember to have some fun too 🎉
4:43 There is a whole episode on how to deal with procrastination hidden in that little bit and I'd love to watch it.
Little tip for the cross slide on the lathe, you can 3d print a drill attachment and get a smooth surface finish with minimal sanding. Try it out next time!
i am making a bioprepellant pressure fed rocket, and i also just picked some numbers: 30 degrees entry angle, 15 exit angle, 6mm throat. Chatgpt also helped me :)
These episodes are so well done, thank you Joe
"A rocket motor, whether it's liquid, solid, or - the worst of both worlds - hybrid [...]"
Solid opener! :D
I used to do hobby rockets when I was a kid... like 6-7 years old. Your channel makes me regret not sticking with it.
Graphite isn’t abrasive; it’s actually used as a lubricant in numerous mechanical appliances. When I worked for a company that specialized in injection molding tools, I would just smother the graphite on the guiding pins of the machines. I have to tell you, it works like a charm, often better than grease even. There are also spring-loaded brass bolts that have graphite pressed into them. When there’s mechanical stress, the housing is abraded and releases the graphite for lubrication.
But you're right, it's really messy and can pose a threat to certain types of electronics. And it's impossible to get your shop clean afterwards :D
Graphite is a lubricant and an abrasive. Turns out they aren't mutually exclusive properties.
The key is the shape and orientation of the graphite particles. It's like a bunch of little pancakes. When they slide across surface to surface, it greatly reduces friction. When the edge slides across the surface of your material, it creates a little scratch, abrading it.
But wait, graphite has a hardness of 1-2, so how can it abrade harder materials? Well, graphite is so soft because of how easily the layers break apart. Get down to a single layer and it has the same hardness as other crystalline allotropes of carbon (think diamonds).
Hey I’m a machinst when you’re boring you can rough out with big cuts .03” depending on chatter from your boring bar but once you get down to final cuts slow is smooth .001-.004” but this is assuming your lathe has enough rigidity to stay accurate. Also a machinist handbook will tell you your slip and press fit sizes (among every other thing on earth) which can help avoid tolerance issues as you know exactly what you need. A tight concentric bore gives you more accuracy this inherent efficiency
If you’re going to keep making more of these you can get a concrete boring drill which is a hole saw that is deep enough to cut 6” deep or more.
You can also use isopropyl alcohol to lubricate the o-rings and leave no residue. It doesn’t damage viton or most other common materials.
If this were an 80's concert in a backroom of a crappy oyster bar, I would be the older guy with a mullet screaming "More, we want MORE!!!" TLDR I like these videos. 😃
If you use an 85 degree chamfer the inner edge of the rocket casing, it might be easier to insert the o-rings and nozzle carrier without nicking the o-rings. In addition, I couldn’t tell if you were using lube. Parker makes a silicon lube I have had good results with. Glycerin is another good possibility as long as your materials are compatible.
Machiniste trick, if you want to archive high tolerance, leave a little bit of material ( 0.001" or 0.002" ) and do the rest with sand paper ( turn your piece with the lathe and apply pressure with the sand paper), start with 80 grit and move to 120 grit. That way you can archive a good tolerance.
I appreciate the details and and the great explanations!
6:15 Pro tip for getting smooth results from your cross slide, knock up a tool that let's you drive it with a cordless drill.
They make cnc China mini lathe replamcnet motors with ball threads too for under 40 bucks 10 years ago last time I could afford mini lathes. Buy alot of it is rigidity m that said if the lathe is anythkjt at all should hlbe able to adjust/replace the ways bearing pads. The factory ones are horrible hell again ack 2hen I coild sfford it my mini mill the collet tool holder was 8mm out of round from enter had a rig fab shop lathe it straight for me so I could make swarf ASAP 🤣
Looks like the way adjustment screwed are way too tigjt they take very precise and tedious fiddling to get just right but should end up butter smooth and be able to be turned with just 2 fingers and no backlash
The ammount of calculation you have done through this channel is insane. rockets are super cool!
From the book Solid Rocket Motor Design, the convergence half angle is chosen between 30-60, if too big it will cause a lost in thrust, if too small then the nozzle will be too long, 45 degree is usually chosen. The optimum divergence half angle is 15 degree, to shorten the diverging section , it is best to be chosen 18 degree. Just as a reference for people who want to design solid motors.
🙃 explanations @1:22 - @1:42 . Pressure begins to drop at @2:10 where and when velocity of gases begins to exit the previous high pressure area which is where the gases hit mach 1+ . A fun thing happens when a high pressure gas is given a tiny exit ➡➡ Because the exit is small at the entrance to the exit the pressure is still high but once the gases begin to leave their velocity jumps way up and the pressure at that point on drops to lower pressure. I understand you understand what is happening but sometimes the explanations are a bit twisted from what is actually happening. 👏👏 If there was not a reduction in the exit vs the diameter of the area where the high pressure gas was at to begin with then there would be no drop in pressure and no high velocity thrust because all the gas would get dumped out the back in mere moments without a high velocity thrust . It is the ratio difference from high pressure to low pressure that enables the velocity thrust we all seek and that special mojo is done via the exits size vs motor/gas area😘. There now I feel better. #Cheerios 🤣😇👊 #Whispers btw its not space its heaven🙏. 🤭🤫. . . 👉🧠👈
G'day Joe.
For fitting your nozzle carrier with O rings installed into a liner.
You might consider using a tool called a 'ring compressor'.
Although the device is primarily intended for inserting piston and ring assemblies into the cylinders/liners of big diesel engines it might meet your needs too.
For getting smoother tapers with the compound, of you put both small handles back on rhe wheel (looks like they were removed), you can chuck the base of a T-shaped piece of metal into a drill, and use that to turn the handles. As long as you have the drill in low gear and keep thr speed fairly consistent, it should work better and give a more consistent surface finish than turning the knob by hand.
Been watching for years. Amazing to see how far you've come and how driven you've remained through the failures and successes. Also, very impressive how far you've come in engineering especially since I believe you got your degree in music, right? Anyways, I know you'll go on to accomplish great things. Keep the vids coming!!
Just finished my phenolic graphite nozzel that will go into my 4in carbon fibre composite motor, Kno3 srb fuel. Might see you in the Mojave desert one day.🚀🙂
1:07 shock diamonds! ! Awesome
I restored a 1926 South Bend Model C 9” Lathe and it’s been great! Still on its original motor too
A small press would help with your nozzle assembly (no dancing required)...a taller press would help installing the o-ring parts. I never thought about all the uses of a press until I spent time with a friend of mine with a really nice shop--he constantly uses his...basically a frame with cross tables and a bottle jack.
We needed long hole saws at my shop and what we did was weld a piece of steel pipe into a cut in half holesaw, worked perfectly. You could do that for the phenolic insulation
Finally! Been waiting for the motors part for years, great work!
Suggest getting an arbor press. Small 1/2 ton, and a larger 3-5 ton. Probably the most usefull tool in the shop. Saves dancing on top of critical one-off parts.
Check out old South Bend lathes! They are phenomenal
I have a 1926 South Bend model C 9” lathe I restored and it’s still cutting great to this day!
Loving this series. Just enough information that it explains it without getting too bogged down in the lingo/details
just as a recommendation for rocket flights, you should put the flight duration/motor burn time up the top. Your channel is the best!
Another excellent video. It's great to see the process. Can't wait to see Simplex soar. Keep up the great work. Ad Astra! :)
I love this simplex series
Your nozzle angles are within reason. One thing to consider is a smaller divergent angle reduces cosine losses, aka some of the thrust being wasted going somewhat sideways out of the nozzle and not pushing the rocket up. By lower I mean something like 10 degrees vs your 15. Although a lower angle means a longer nozzle, and thus more weight, so it’s a trade off.
0:48 "A rocket motor that is solid, liquid, or-the worst of both worlds-hybrid..."
Wow that's so offensive to hybrid motors (I 100% agree with this statement)
Suggestion: for future grain packing, 1, when you think you have all of your propellant in there, place a weight [or springs, or air pressure in a cylinder] on it with some packing material [such as beeswax or modeling clay in a ramming tube, and then 2, put a vibrator or ultrasonic horn under it to ensure all of the bubbles expel while none of the propellant fluffs, spalls, climbs, creeps or ripples.
All of that would be using a fitted removable sleeve, something like PVC pipe is fine for this, and its cheap, and can be resized with heat if it is not a perfect fit. Be sure to clamp it though, so even if its a perfect fit, the pressure does not squeeze anything out, or pop the sleeve off.
This should only take between 30 and 60 minutes but it should really clean out all of the voids.
What will happen if there is entrapped gas is, just like with concrete, it will work its way to the top and exit.
Since the clay [most modeling clay is actually quite light, but beeswax is much lighter if you can get it, say like off the internet] is somewhat lighter than the propellant it will continue to float on the top but the bubbles will float through it.
I suppose you could mix up some flour and water into a sort of a dough, but it could have too many elasticity issues and make it impossible for bubbles to pass through it, or, on the other hand, you could use wet or dry sand, but then sand is kinda heavy and would certainly mingle and embed in the propellant, unless you had an excess of propellant with the intended goal of just cutting off the excess as waste, so that would be a decision to be made at that time.
Honestly, either way, it would be good to have maybe an inch or two of extra propellant on top of the mold anyhow, because when the bubbles escape, you want to refill that void with propellant, not packing material.
"that's my nozzle. And it's a pretty good fit"
my new pickup line
Thanks Joe. You're sort of single handedly making rocketry cool again.
"thank the sponsor of this video, which is brilliant" made me smile a bit.
Fascinating journey so far, I'm so glad you're making these videos. Thank you!
This guy feels like the next amateur spacex
"amateur" is honestly an insult to the type of batshit crazy stuff Joseph Bizzlington is doing here.
@@mirandahw well, he is a amateur, he has a degree in music not in aerospace. Being a amateur does not mean you can not do awesome things
@@ekkekrosing8454 Technically, he makes money doing it through the channel. So, you could consider him a professional... But that's just semantics.
You can’t say he doesn’t look a little bit like Elon musk too…
Who do you think was the first Amateur SpaceX. :D
Very great, i really like the effort, pusing the ebay lathe to make this Nozzle😅
New video and New Amazing Video from Jr. Musk👏👏
Thank you Joe! Your vids are awesome!
This is intense! Serious work.
Oh boy! You are making history here! As usual your videos are very detailed and at same time direct to the point! Please keep doing this amazing work! You "rocket"!!!
Watching these videos in public places (like I have any freaking idea what is going on) is my new favourite hobby.
I’ve secretly never felt so intellectually inadequate in all my life; but that doesn’t stop me from enjoying following the story! 🚀
Very impressive. And filming it while working on it makes the task about 10X harder.
Its both crazy and amazing how much work goes into making a rocket motor
Great work. Currently learning in Collage how to design a rocket nozzle. Nice to see this in a real world example ;)
For those slow increments on the lathe, This Old Tony has the solution.
Use two small T-welded iron bars and a screwdriver with speed control.
11:30 I can’t help worrying about the O rings getting damaged by the way that you brute-forced the nozzle carrier into the motor casing.
Have you thought about using the same type of tool that car mechanics use when they install the pistons into the engine block?
It’s called a piston ring compressor, and I believe that using something similar, could greatly reduce the risk of damaging your O-rings.
(And make the install a lot easier.)
Cheers from
Vejle, Denmark 🇩🇰
Good to see you both back.
I too play with all different kinds of electronics. At the moment the TomTom 550 is on but just got a mount to fit the bmw navigator fitting.
Dude forgot to stop... You have to admire the passion in the man. Please don't change.
"Tolerance errors can stack up."
I have a picture somewhere that demonstrates this really well. Steel lattice tower welding jig was off very slightly. For an individual 3m section, you couldn't see anything wrong, but getting the pieces to mate was somewhat difficult. Once it was stacked to 100m? You could look up the leg and see the entire structure was twisted.
Ended up being something like $150k insurance claim to cover the labor of dismantling the structure and putting in a new one.
"Wood on a metal lathe! Absolute disgrace!........ I mean there is nothing wrong with wood on a metal lathe is ok?" - Ewan 2023
Dude you are such a legend. Have you thought about sharing your knowledge and process of iteration with students? You will without doubt inspire even more minds.
Great work on the machining Joe!
Thanks Brice!
Absolutely loving this series, can't wait for Ep 4.
3:35 I am sure the neighbors agree with you 😂
Have you tried wet pouring your mix into the casing, tooling installed, pull the vacuum on the pre-cast material that’s already in the case. Maintain the vacuum through the cure and then remove the tooling. No voids, perfect cast, tooling form is removed and you have a near perfect motor casting ready to shit and git.
Attach a cordless drill to the lathe carriage. You'll be able to move it smoother and easier on your hand after a while. Wouldnt nessecarily reccomend it for metals, but softer materials will work fine.
For safety you might want to get a positive air pressure mask to keep the bad stuff from your lungs.
On turning those tapers: Don't you watch This Old Tony? Power-drill cross-slide attachment!
The parts turned out great considering the machining troubles. Looking forward to the next part :)
Rocket since: "Why i do this? Don,t know, it's just look right":)
Good luck with your experiments!
12:50 next time i recommend 3d printing a tap alignment guide as well
You might have seen or heard of them before, but you should look into getting some form taps/roll taps! They take some time to get familiar with and require somewhat specific drill sizes for your target thread form % (between 65-75% is where I've been getting fast reliable results), but you can look up the ideal drill diameter on a form tap chart as a starting point and then order a few sizes +/- the nominal drill diameter to dial things in for specific applications. I find if I'm cnc or drill-press drilling, the "correct" diameter typically works best, but for a hand-drilled hole, going slightly undersized seems to help account for inaccuracies from hand holding the drill which typically results in oversized holes compared to being drilled perfectly rigid and square to the surface as with a cnc/drillpress. With the optimal drill diameter figured out, I find that I can run m3 to m6 form taps with a hand drill and knock them out in quick succession(...but maybe don't try this immediately, getting familiar with the feel of the form tap going in is important too).
These taps also have some unique benefits/tricks/quirks, the first of which I think would save you some headache with your nozzle carrier:
- No chips to clear! It's a huge time saver. Depending on your lubricant/material, you may occasionally have to clean away finely powdered debris which builds up in the relief slot. Isopropyl alcohol as a lubricant for aluminum is amazing - not sure on specifically why, but it lubricates aluminum extremely well and also washes away any fine debris between holes with no oily residue to clean up afterwards.
- The threads are typically stronger due to being cold formed rather than cut into the material. (ymmv depending on material and the depth of the hole though, brass is a nightmare in my experience lol, and I'm sure there are other materials which don't like being cold formed)
- Form taps can last an extremely long time compared to cutting taps, assuming you don't snap them first or run them through undersized holes and gall material to them. 😂
- You can get "extra" threads from an open bottom form-tapped hole which can be used to your advantage. By using a slightly undersized drill diameter on thinner stock materials, when you run the tap, the threads bulge down/out as the tap exits which gives the fastener a bit more thread length to engage with. This can be problematic if you're tapping a tube wall where an internal and removable slip fit might be required. If you tap both the tube and the part within, it can also effectively lock that internal part in place with the displaced material. You could use this to your advantage though for extra part retention force too, it all depends on how you use it. Conversely if the material is too thin and too soft, then you might not get any threads at all as it might not have enough resistance against the tap, and just moves aside entirely as the tap slides through.
If you do decide to try form tapping, I find that the polished/uncoated taps from Mcmaster work best with aluminum/isopropyl for every day applications. The TiN or TiAlN coatings can get 'sticky' with aluminum, and that's just a recipe for disaster with a form tap. For harder materials, Loctite LB8012 moly-paste works great with the polished/uncoated taps as well. I've tapped both titanium and stainless steel with that combo and the threads came out really nice.
Hope some of this is useful info! Excited for the next video in this series!
-Mike
You might think about making a piece with a conical inside bore to help you slide the cap with o-rings into the case, rather than risking pinching and compromising an o-ring. IC engine builders use them to compress piston rings during insertion of the pistons into the bores of the block.
Very interesting, but my inner space-nerd-fan-boy really wanted to see it go bang!
I'm learning every time I watch your vids!
I love the name Simplex. it's a simple name, but the deeper meaning is still complex.
Thank you for sharing, your video is very good and amazing
Awesome stuff. Good job!!!
Does your mom know how dangerous your toys are?
Regarding the phenolic, why not build a jig with a bandsaw to get it round first? You're going to bore the center out of it anyway. You could drill a 5mm hole in the middle of one face, and pivot it around that on the saw. then turn it as normal on the lathe? This is how Frank Howarth does big bowl blanks in his woodshop.
3d printed drill guide is a nice idea. Even for a production environment if you don't have full CNC
Yeah! It worked better than I thought - an indexing head would be more accurate, but this was good enough
Damn, I'm a turner by trade and it's still seriously impressive how far you're taking that little lathe. It's a shame I'm in the UK, or I'd happily turn some parts for you on my cnc if you needed it
Man i know nothing about rockets and i don't want to know either but for a long time i watch your video's and i laugh my ass off and i have immensely respect for your skills and ...humor ... a fan from The Netherlands ... keep it up and good sailing!!