@@ChrisRosser unfortunately it doesn't to me mate, its a great category don't get me wrong!! Here in Australia our limit is 100grams before alot of laws, rego and stuff are starting to really kick in. FPV is technically illegal anyways even on private land with hundred LOS observers in this country. So I've been just chasing to ultimate flying fun under that weight. To me once I go above 2.5inch I just go full size as sound attracts same amount of Karen's etc around. Google wing delivery drone fly constantly over my house and my flying nature reserves they want us hobbyist out of there way asap.
Great video. Finally someone tackles carbon layup for FPV. I always wondered why no one used 0,+45,-45,0 or +30, 0, -30 or similar layups for arms. But it seems they are not readily available as plates, so that may be the explanation.
We at Madkwads have done that since 2018 and I suspect Chris got the idea from us because I explained the concept to him in a private chat. After that he started looking for other manufacturers that could make plates for him leaving out the part with IM-fibers and TeXtreme spread tow fabric.
I remember Bob Roogi put us in touch early on when I spoke with him about optimizing CF layups. I know we spoke about simulating different layups in FEA and it motivated me to create the code I now use to calcualte the coposite porperties of different layups. Unfortunately the cost of Textreme (particularly for larger thicknesses) was prohibitive. Fortunately the tool can be used to optimize layups for any material set. Cheap or expensive!
@@ChrisRosser Yes, But we have reduced that now by investing in a high pressure press and a cnc machine. This way we can reduce labor and shipping cost that earlier was a big part of production cost.
I have flown frames from Madkwads which reminds alot of what you are talking about. They fly very good and have great durability. Also exceptional stiffness with just 2 mm arms.
I believe MadKwads use their own carbon fibre fabric "Textreme" which is certianly a high grade material but I'm not sure they have the layup optimized specifically for each part (I've been speaking to them about this as recently as a few months ago). The software I've written allows optimization of any carbon fibre material set so perhaps there is some overlap there.
@@ChrisRosser they most definitely have optimised the layup of the CF per part. I've seen the way they do it first hand. Reach out to Johan and Oscar and they'll for sure be able to confirm or deny this claim
Back in the '80s I was a bicycle geek who was learning about the new-fangled carbon fiber frames that were coming to market. Part of the promise of this then-expensive-and-new material was the ability to customise the lay-up of the build. Here's Our Chris, fulfilling prophecy. Dang, ain't engineers wonderful?
I'm really pleased the cost didn't go up too much when customising the layup. Higher grade materials are 2x the cost for 20% more performance. Now we can get the same benefit with the cheaper material for only ~25% more. 😁😁😁
Hey, Chris. Solid video as always. My opinion on the t700 carbon is you should absolutely offer it as an option for the AOS frames. Personally, I would like to have all of the body plates be t700, while the arms remain t300. This is because I would rather snap and replace arms than ever have to replace a body or camera plate. I don't speak from any experience with frame design, so if what I said isn't necessarily correct, please advise :)
Madkwads took the approach of using higher grade and more expensive materials to get more performance. The nice thing about optimizing the layup is it makes any materials set 20% better! So you can improve cheap CF and expensive CF as well without adding any material cost.
@@ChrisRosser having helped production of MadKwads CF during a weekend I can assure you that they have put a lot of effort into optimising their CF layout. Just putting their achievement to more exotic materials is selling it short. They have done the work with material spec and it's layout, maximizing the performance to the expense of higher cost.
@@selaI3 Yep, you are quite right looking back through my conversations with them I calculated their layup design added 30% torsional stiffness and 6% bending stiffness over standard layup.
Great video Chris. Just couple questions for you. 1) What is the process to manufacture those cfrp? Is it standard room temperature vac bag process, autoclave or out of autoclave (OOA) method? 2) Did you use Unidirectional cfrp in your new design? 3) Why don't you use standard mechanical properties testing like tensile and bending stiffness? Whatever it is, you did a great job and appreciate your effort.
1. The material is made exactly the same way as cncmadnesses standard layup by the same company out of the same materials only the fibre direction is different. I think its a vacuum infusion process and then cured in a heated hydraulic press. 2. AOS Arm carbon uses only Unidirectional carbon fibre in the layup to maximise the fibre volume and the straightness of the fibres. The UD layers are oriented in different directions to provide the right balance of stiffness. 3. I do what testing I can. I don't have access to expensive test equipment, I'm just a hobbyist. I do flight testing and blackbox to confirm the simulation results and my sims are currently within 5% of test results. This gives me good confidence in the approach but I'm not a big company, just one guy doing his best.
My thought on price for frame material is that since the cost of electronic components as gone up so much, the cost of frames is relatively low. Paying 85% more for the frame would still only drive up the cost of the build by around 10-15% assuming you are using premium components. If you took it further and only used the T800 for the arms, the relative increase of the build would be even smaller. So I would definitely be willing to pay more for more out of my frame.
Great new videos Chris. Definitely agree with the increased engineering on Quadcopter structures that opens up more room for the FC behavior to operate at a lower delay 👍🏼
I'd love to see the performance of a crazy strong carbon like t800 or t1000 for the arms (both reduce the resonance and strength during a crash) with this weave method. And maybe a more stiff carbon fiber on the frame (stronger than 3k but also going to reduce a lot of resonance). It might be expensive as hell but it'd be pretty cool to see the results. I'm sure some people would drop $200 on a frame if it meant it was borderline invincible and flew amazing.
I'm working to make T700 available for my frames. T800 or T1000 is something that I might be able to do as part of special editions with limited runs due to the incredible cost of stocking the material.
I believe Madkwads achieve their performance through use of high grade and expensive materials. I don't think they do layup optimization for their quad parts (I was speaking with them about this a few months ago and they were asking if I could work with them on that). My approach uses standard materials rather than proprietary fabrics so its much cheaper and I think more suitable for mass production.
@@ChrisRosser layup optimization is 90% of what they do. The higher quality carbon they use sure plays a part but it's not as easy as just throwing more money on the CF itself to achieve what they have
@@ChrisRosser We do use higher grade material then most others but it is not proprietary. To reduce the cost and speed up production we have recently invested in a high pressure press and a cnc machine. This way we can reduce labor and shipping cost that earlier was a big part of production cost.
@@LongcatFPV The layup is not a major contribution in stiffness and bending strength in cf mechanical properties. The process such as higher pressure curing machine and hi-stiffness material (obviously expensive) is the major contribution. If you said 2mm is hard to bend, it is 90%+ manufacturing process and material. *Just got little experience in manufacturing and testing cf panels/parts for A320, A350, B787 and A400M.
@@madmanjohan Thanks for clarifying that Johan. From other comment threads it sounds like you do layup optimization for each part. Do you use different layups for arms and plates?
love the fpv specific material science. I work with high end carbon bicycle frames and love to see the effort to push fpv frames into that realm of manufacturing. I want to see a molded carbon fpv frames and parts. Like the Iflight morgoth! I liked mine it was low drag and light weight but broke very easily.
I am currently running modified stackups for the arms on some of my quads. Also toyed with rohacell-cored material and an extra skin to regain torsional stiffness. Also made a frame with tubular arms. They all are far better than plain 0/90 regarding bending stiffness and ultimate strength, but the drawback is lower crashability. In the end the crash energy must be distributed through the frame to keep it in one piece. Maybe more elongation before break would be better. Aramid+glass seems promising
That is probably because rohacell can't handle the shear forces in the center of the laminate. That is also the reason why anisotropic laminates can handle more load. In a 0/90 layup you normally end up with delamination in the center 90deg layer because in that layer shear forces are highest and all load has to be handled by the resin. Aramid and glass are/can be just as strong as carbon but they both have far lower modulus. That is why we all use carbon - it's stiffer. The other downside with glass is that it is heavier.
I would, but I would definitely would if you used different material on different layers. What would be ideal would be semi quasi-isotropic (biased for 0deg) layer-up using an alternating combination of M30Sc (int Modules - 294Gpa\5.94GPA tensile modules\strength) and T700 (standard Module - 235Gpa\5.3GPa) layers. This combination would give the best stiffness and strength for the price and will as this will raise the resonance frequency significantly. I also believe the outer Weave can make a significant difference. For example, Textreme Spread Toe used as the outer layer is far better than standard twill for dealing compression and expansion forces. I believe the Karearea Tora uses T700 CF I look forward to something like this being available in 5mm or 5.5mm thickness for my AOS 5.5". (Fingers crossed)
It's a great idea! Using different materials for different layers would be a big change to the manufacturing process and might add a lot of cost needing extra reels for the different materials and extra QC for verifying that the right material was used on each layer. It would probably be cheaper just to use a higher grade fibre throughout to keep the manufacturing simple. I would be interested to learn why textreme is better than a standard woven fabric for the outer layer. I guess they are using a higher grade fibre so the material is stronger (but also 2x the price!) A spread tow weave is pretty common for CF and makes the outer fabric layer thinner and gives a different look but I'm not sure there is a mechanism to give an enormous performance benefit.
We at Madkwads do use T700S for the middle of the laminate to build thickness and M30SC on the second outermost layers where they make the biggest difference to performance. There are several advantages to TeXtreme. One is that it is much thinner so for a set thickness, say 5mm, you can fit more T700 and M30SC UD layers that improve the perfomance compared to a thicker 3K weave. The angle the fibers have to take to get over eachother inside the weave is much lower compared to thicker weaves. This improves the compression strength of the weave. Finally - it looks spectacular! With a mirror finish on the plate it is just stunning.
Oh this is the stuff madkwads uses! They are the absolute best in the carbon game! We use their carbon on our frames and its game changer. How ever is that stuff not proprietary. I know they make stuff for huge car brands and more.
Madkwads have their own carbon fibre materials set and its quite a lot more expensive at around 2x the cost of standard CF I think. This is a layup optimization so it can be used with any grade of CF from any manufacturer that can make standard layup. This makes it potentially much more economical for mass production.
@@ChrisRosser yeah well I have used theirs and its done wonders for my frames. I dont mind spending a bit more to get the absolute best. But I guess many people here want to be cheap and get stuff as cheap as possible. Since I like to have stuff that lasts i dont mind paying 100euros for a frame when its much better then the 50€ frame. Its all about how long will it last and how much less time do I have to spend on repairs. Also they have been doing this for so long they know their stuff. I would recommend them to any one who wants stuff that lasts and not who wants the absolute cheapest way to get something sort of like it ;-) But cool that your talking about new types of carbon. Its always interesting.
When an aerospace-engineer friend visited me and stared at my quads, his first question was "why aren't you using carbon specifically aligned to the arm directions? I feel there is a bit of potential left here." I couldn't answer better than just saying "yeah, they just cut it out of standard sheets." It seems he was right after all ;)
I've made a lot of custom racing frames. I've broken a lot of these frames. T700 is the best - it's a lot stronger - you can cut about 30% of your arm width using it and get the same durability as T300. What I would like to see for racing frames - isn't strength or stiffness - but a material with a much greater plasticity - where it can take a hit and not break or turn into a "noodle arm". All my race frames a 5MM. There are some really interesting composites that an aerospace fabricator had scrap of that I never dived into - PEKK and PPS composites.
I'm working on bringing thermoplastic carbon composites to FPV. They have most of the strength of epoxy CF but are much more durable. They bend rather than break and you can straighten them out with a heat gun!
I developed a frame where the lay-up and shape is optimized. I used T700 UD / T700 Twill / Inegra and Aramid in later versions. Commercally it was impossible to get get any profit out of it (even at $119 for a frame) but it was a very nice (but expensive) hobby project. From an engineering perspective I think you would like it very much. I still have a few laying around, if you want one let me know I will send it out to you.
ill be interested to see the crash data on this and how the very separate layers although joined, act on impact. as the 45 deg. layers are sandwiched in the middle i will be curious to see how they delaminate on impact. I would assume that having the 45deg. fibers be spread out more uniformly in the layers would provide superior strength then them being positioned only in the middle {ie quasi isotropic), however, this is an assumption based only on my limited experience i am not a schooled engineer.
Yes, I am interested to see how these arms break when crashed really hard. You can be sure that if there is room for further improvement I will adjust the layup design! As far as I am aware the 45 degree layers are best placed in the middle because they have the same effect on stiffness wherever they are. The UD layers are better further out so they go on the outside. Quasi isotropic is a sepcific layup with 25% 0/90/45 and -45. AOS Arm carbon is an anisotropic layup not quasi.
Yes please Chris! I love my AOS 5.5 and build the Falcon 7 right now ... As next project I would like to take on your AOS 7 Mantis. If you offer frames in higher quality CFRP would be really great! 👍🏻 Also I would love to have forged carbon on the outside for cosmetics. 🙏🏻 please Maybe an option to choose between satin or high gloss finishes would be nice especially for forged carbon finishes. Do you think this might be possible to request to your supplier? My understanding is that they custom cut for each order anyways, hence there should be no issue with slow moving or dead stock when offering more options.
Hi Matt, I'll certainly look into it for you. You can always ask Nick yourself when ordering an AOS frame from CNC madness if he can use a higher grade. It really depends on what material he has in stock as its stocking a material that costs money (both to buy the material and the space to store it).
@@ChrisRosser Dear Chris, I was reaching out to Nick under the mail address you shared above. Unfortunately I could not get a reply. I really would be happy to have the forged carbon option. The option choosing higher quality carbon for my AOS 7 build would also be nice. I am waiting to order the frame and hope options are made available sometime soon. Thank you for all your time taking a look at this. Have a good day!
Great video Chris. I would like a 7" dead cat frame for video work? not able to see the props and use the DJI air unit, will you be making aframe like this?
I haven't looked into Kevlar. Because Kevlar is less stiff and less strong than CF you wouldn't want to mix them. The stiffer CF fibre would end up taking nearly all the load. The failure mode of kevlar is more stretchy so it might be more durable in crashes.
As always i got a lot to learn about what carbon fibre is and what one can do with it. it serves for very good morning motivation for me to learn more about technology and sets me up for a day full of scientific discoveries about things around me. Added to all of this I have always wondered why do companies cut frames from different sheets of carbon and why not mould them into shape like how top supercar companies like koenigsegg kind of bake individual parts. Does it add more labour into the process that way? is it good to waste some material and reduce labor that way ?
Moulding carbon fibre is very labour intensive and labour is a huge part of the cost of carbon fibre parts. Also you need to make a mould for every part out of aluminium which is tremendously expensive. With flat sheet you can cut out any part from the sheet with no tooling cost.
Hey Chris, is there any chance to make arm carbon standard (or optional) for all AOS frames. Or more specifically: as a standard (or option) for the AOS Falcon frame?
It is something I'm actively looking into. It will take some time to get manufacturing set up for the material. At the moment I only have 5mm in stock at CNCMadness.
@@ChrisRosser that would be awesome, in that case I have no doubt what frame to go for for my upcoming 7" LR build (referring to my comment on the other video). Please let us know if/when it is implemented on the AOS (Falcon) Frame(s)!
Chris excellent video as usual! Iv’e noticed that %95 percent of the quadcopter arm frames I’ve seen are solid carbon fiber. If one wanted to use T800 or T1100 carbon fiber wouldn’t it be beneficial to adopt a design for the arms with a hollow center to run the motor wires through? This way the aerodynamics will increase and in theory be similar strength to a solid rectangular T300 or T700 carbon fiber arm with less weight 🤔. I’m not an engineer but it was a thought that ran through my head for additional weight savings.
Hollow arms are a great idea and some larger quads do use tubular CFRP. However, the mounts for the arms are very heavy so its not beneficial for smaller frames. Also tubes are very stiff but not super durable compared to solid CF. For quads that must crash well solid CFRP is much better.
Now that arm cross-sections are getting squarish, is it time to use hollow tube arms to save weight and maintain rigidity in a 5" quad? Also since carbon is conductive and can block transmission from short antennas, should frames be made from S2 glass?
the issue with tube arms is mounting, performance wise they would be great, but they are much harder to incorporate into the design of a frame and also come with manufacturing challenges.
Hollow arms are tricky. You risk crushing them in the mounting and the mounts tend to be a lot heavier and more complicated. Definitely useful for big quads (X-Class) but not so much for little ones I think.
Great insight into the process. I had some idea and this helped. Would really like to see the science behind those formulas, but I bet they are very secretive.
I put a lot of work into the software that calculates the performance of the layup. If you want to learn more here is the lecture course I used to learn what I needed to know to do this: ua-cam.com/play/PLREHQnoFMsHAuaShRdNQ1-tsE_r8qS6dh.html
The problem is that T700 or more or less any other fiber that is stronger then T300 are not made in 3K (3000 filaments in each tow). T700S is most common in 12K and if you would weave that it will be very thick and full of pinholes. The waviness would also reduce compression strength alot. The solution is to use spread tow fabric like TeXtreme because then you can use the stronger fibers that are only manufactured in 12 or 15K and still have a fabric that is half the thickness of a 3K fabric with T300. That is one of the reasons we only use Textreme as outer layer in the laminates we make at Madkwads
@@madmanjohan Thanks, I did not know about the availability of T700 fabrics. So do you think betafvp uses lower grade carbon for the outermost layers on their frames advertised as using T700? Spread Tow fabrics are great, but if I remember correctly, quite expensive. So I don't think using those is warranted in a more cost focused carbon layup incorporating a lot of T300. Maybe one could use unidirectional carbon to have a visual distinction for the "arm carbon". But I think maybe I was not clear enough what I was going for. Assuming pure vertical bending, and assuming the cured layers behave like the fibers (same stiffness, T300 has 70% of the strength of T700) you could use T300 in the center 70% of the plate and use the stronger fibers only on the bottom 15% and top 15% of the plate. This would result in a plate with the same bending strength as a plate made only from T700. To be safe, and to account for other loading directions, I would use a 40/60 or 50/50 fraction of T300 and T700. Of course this calculation is simplified but I think you get the idea. This is probably most useful for thick arms. The thinner body plates are loaded more in tension and compression (and not bending), at least where they sandwich the arms. So i think it is better to use only T700 or IM carbon for those. For these thinner plates the material cost is probably relatively less important considering labour and machine time, anyways.
@@LS-xb2fh Yes, when claming T700 lamintes most manufacturers referes to the UD layers. Spread tow is more expensive but our goal is not to make a cheaper laminate. If low cost is your focus then go for Chris laminates. A laminate without a weave as outer skin is far more sensitive to impacts. If that does not concern you then you can go without it. I understand what you are going for and that is what we have been doing at Madkwads since 2018 - just one notch higher in grade all over. Instead of using T300 as the cheap fiber in the center we used T700. Instead of using T700 as the outer UD layers we used M30 that is a intermediate modulus from Toray with similar performance as T800 but more impact resistant. This might not be what you are after (to expensive) so Chris concept might be better (cheaper) for you. One thing to keep in mind is that carbon fiber have only 60% of its strength in compression compared to tensile load. Another thing that make big impact on both price and performance is layer thickness of each UD layer. Many thin layers perform better but are also more expensive to manufacture.
@@madmanjohan I appreciate your in depth answers. Your composites and frames absolutely look great. But I think for most people the very highest quality is not worth it. Most would rather spend some extra grams than extra dollars to get the same stiffness and durability. So I think for higher quality composites to be widely successful, they need to be not that much more expensive (and marketed well, like calling it "arm carbon"). Edit: And with higher quality I mean better fibers, an optimized layup and a combination of both. I hope that in a couple of years all but the cheapest clone frames will use at least a somewhat optimized layup for the arms, and higher carbon fiber grades will used be at least somewhat more often. Additionally, replacing some TPU parts with Formfutura Pegasus PP ultralight might be a more cost effective way so save weight, compared to going for the best carbon. It has a density of 0.75g/cm³ (TPU: 1.2g/cm³) and is adequate for a lot of applications on fpv quads. Regular PP is fine too at about 0.9g/cm³. Edit: This way to save weight is useful at least for freestyle frames, which use way more TPU than race frames.
A point that is worth making is that optimizing the fiber layup provides increased performance for all materials. So if you use a more expensive material and optimize the layup you still get +20% more performance on top of the benefit from the better material. You don't have to do one or the other, you can do both. For internal layers I think UD fabric is the way to go. You can use any grade because tow doesn't matter and you get the best performance. I think the outer layer on a 5mm thick arm is mostly cosmetic. A woven fabric might look nicer but I'm not sure it gives much performance benefit. AOS arm carbon uses UD for the outer layer for one very important reason. The orientation of the parts is paramount. You MUST cut them aligned correctly. Having the outermost layer UD and aligned with the strong axis allows the machinist to easily confirm which direction is the strong direction with one look. This minimises the risk of parts being cut misaligned.
Been using CF in rc myself for years...vac bagged wing gliders and planes , boat hulls , cars..etc...I agree with all that was said and will add that I find some CF quad frames to be laid up way too lean almost starved of epoxy in places...epoxy costs money but so does a bad reputation...
Stiffer but less durable than solid carbon. Also the mounting for tubes are very heavy and complicated which makes it less suitable for smaller drones.
3 роки тому
if this special carbon is better then what we normally use can we get away with using thinner carbon for the frames? as it is now a 6x12mm arm on a 5" is all but indestructible.
Way to go mister Rosser I'm extremly interested in this I would like to see how this turns out would we be able to order arms for any quad using this aos arm carbon ?
I've got a feeling I'm missing something obvious regarding the different layups. Both Standard and Quasi Isotopic layup use a 90 degree offset between directions. Why is this stronger than using a 120 degree offset? Or is it more ease of manufacturing cost/benefit? Hexagons are bestagons, but with Carbon Fibre it's all based around 90 degrees. I'm sure it's been tested and found inferior, just curious why. Great video as always, love getting a glimpse into the nitty gritty of the incredible materials we use!
You are right. The other (and better) way of doing quasiisotropic layups is 0/60/-60deg layers. When we at Madkwads built out own press and started making our own laminates in house, we could easier play around with fiber angles. We then found that 0/60/-60 worked better then 0/90/45/-45 for the midplates in our MAD-LITE frames. It is not a universal solution but in our case it proved to be better
The 90 degree offset is simpler to manufacture I think when making a rectangular sheet. The best fibre orientation depends on the loading case for the part. So there is no best layup. AOS Arm Carbon is the optimum layup but only for straight quadcopter arms!
There must be CFs that have better vibration absorption than others. blend in some Nyogel in the resin Matrix.... (i have no idea If i'm using these terms correctly. smack me down appropriately) I'm thinking of joining two 1.5mm babytooth frames with some sort of Viscoelastic Damping adhesive, maybe same for joining 2 3mm arms for 7"? the test needs to be... same frame design... Cheapest CF, Best performance cost no object (within some reason)... then bang for $$$ Does it perform better.. last longer... how much soo? The layup though is where the real magic is from my understanding. From watching F1 suspensions over the years... think most of the tuning is the directions of the layup.
Using a 3mm arm is better than combining 2 1.5mm arms. It is way stiffer, so the resonance frequencies are much higher. And not having low frequency resonances in the first place is superior to highly damped resonances (which is better than low frequency resonances with low damping).
L S is right that one thicker arm is better than a sandwich because shear stress needs to be transferred through the material and that doesn't happen with a sandwich. The grease is always going to work best at the joints between parts because that's where the most movement is. The arms themselves don't move as much (I've tested viscoealstic tape on the arms and it doesn't work as well as greasing the joints with PG44A). Layup is definitely the way forward because it helps cheap and expensive CF just the same.
The truss gives much more benefit than the material change. The AOS 7 uses a split truss design that might be amenable to AOS arm carbon. I will definitely be using the material where it gives a benefit in future designs.
@@ChrisRosser I guess this would just be an unnecessary cost increase, but maybe you could make a layup where some sheets are inline with one of the struts and other sheets with the other strut.
Wanted to say Great Job on the AOS series. Right now I have two 5" frames; the BotaFx by Bot Grinder, and the Switchback from Evan Turner. I listed them because both are top frames in their respective disciplines. Your AOS frame (for me at least) is one more example of a frame meticulously designed with a purpose. It inspires me and I will be building my next drone on that frame. Thank You for your contributions to this hobby. (also don't mind Mr. Steele he had his mind made up before he flew it, everyone has off days)
I'd love to know what Emax is using on there 5inch racer arms to make them so stiff. To compared my mates switchback the arms are so strong, I'm still yet to break one in a crash. At races they have metal poles and yeah it's a test for strength haha. After a year of crashing the end is starting to Frey a bit though. But probably flown 500 plus packs half of which a crash in the flight of some kind haha.
Looking at photos it looks like the arms are relatively beefy and made of aerospace grade CF (60/40 or better fibre volume) which will make them very strong.
@@ChrisRosser makes sense mate, I've always wondered about it. Tried a few different tight race frames and it blew me away the strength they got with the simple design, especially as its an old frame now. But I'm saving for one of your frames as I'm really genuinely impressed by all levels of thought and time you've put in. Thanks again mate and I do hope you stick around in FPV into the future and don't get burnt out by some of #&%! that comes in hobbie for designers and innovators. Cheers.
@@ChrisRosser You can't tell resin content fraction by looking at an image. However you can tell by measuring it's density. Aerospace grade is just a certificate - it does not mean it stronger in most cases. T700S sold both with and without aerospace certificate and they have the same property's.
@@madmanjohan Always learning on this channel, even in the comments. Cheers mate, what ever they done they made the strongest arm I've used on a 5inch racer quad.
If you use a higher grade fiber the frame will be stronger and stiffer. The only downside is the extra cost. I'll speak with Nick and try to get it added as an option.
Would you be able to show the actual design details without hurting your plans to sell it? I'd be curious to see how exactly you achieve these figures. Thanks!
The concept is called anisotropic layups. The short explain is that the laminates have a layup that similar to a quasi isotropic laminate but with the 90deg fibers removed. Instead you only have fibers in 0, 45 and -45deg direction. We made a video about this two years ago where we try to explain the concept ua-cam.com/video/_WGNU6tphYI/v-deo.html
Johan is spot on but the real key to AOS arm carbon is the *balance* between the number of 45 degree layers and 0 degree layers to get the right mix of torsional strength and bending strength for the quadcopter arm application.
I am a huge supporter of t-700 carbon frames they just take a beating like t300 can’t. Hint personally tried t-800 but for me I’d rather pay more and have way better durability. So my vote is yes AOS frames should be offered in T-700 and or T- 800
Thank you Chris for your work. Seeing a new carbon with less flex makes me immediately think of airplanes. Not RC ones, the big ones. That should be an interesting industrial avenue. Second, it could also be of value for ultra light toothpick style frames. I really like the work Diatone did when creating a frame made of squares. It increases the stiffness while not impacting weight. Now if your style of carbon sheet can further slim down arms… That would be heaven 😉
What I have done is standard practice in aerospace, automotive and cycling industries, even high end golf clubs have optimized layups. Just trying to bring the tech to FPV 😁
I'll definitely see how this new material can be applies to truss arms. The AOS7 uses a split truss, I wonder if that could be applied to the AOS 5 which is much smaller...
I would not claim to be a guru, just a professional engineer with training in materials and composites. Optimizing fibre layups is pretty standard in automotive, aerospace and cycling industries. Even high end golf clubs are doing it nowadays. I'm just doing the same for FPV quadcopter arms and making the material available to the community so you can cut your own designs from it. I think that's a good thing to do, rather than keep it for myself.
@@ChrisRosser I actually misunderstood what you did. I took it you used your software tools to select a set weave and preformed plate albeit higher grade and cutting arms etc, but adding a bit of educational razzle dazzle to fox the customer, my bad. If you're engineering them that's fair play and I'm as I guess your generalisation would be a stress engineer no? A good person for it, can't you make props quiet next?. I'm super defensive of real engineering and engineers that actually engineer at the moment sensing extinction ((and it can be software to stone masonry in my books) and because an academic/scientist only makes the transformation to engineer, by engineering something 😆 not holding the certificate, i see more potential engineers in the FPV community, whether as a blend of pilot and technicians to fly and maintain or more exciting, a place for the pure engineer builder, credited for now or not. Maybe a place for our kind once again to invent and engineer in the world or how else can it manifest? and we should grow and build especially nationally. Theres a massive boom coming that might be remote aviations niche, we would be the remote aviators then lol. Or mass imports will fill any void which we might scrape off the 40 billion growth predicted and I see you are helping those engineers so fairplay. As an aerospace engineer that saw the a400 EIS at airbus military R&D nearly 20 years ago and more recently a couple Italian M346 prototypes, those being mostly composite I'm a little educated. From a practical standpoint I might suggest that if you control the layup you also have control of introducing techniques such as instead of only vacuum perhaps you could engineer a press and gain greater densities, If then have a hot press could composite/laminate anything in kevlar is instant safe option but not sure qualities, surely and maybe combo with 3d printed moulds to allow pockets of foam or sorbothane etc in the arm, not too tricky to industrialise small. Also its a smart direction you are taking by stiffening everything to gain high frequencues that are more easily squashed by cancelling it essentially as gyro noise, but as an evolution, might it not mess with other high frequency RF or nav functions when they need the precision/clarity? I guess they are damped at source then but maybe combing electronic and mechanical dampening also serves?
@@DigitalArtisan77 No worries. Easy mistake to make. I'm using standard fibres and resins but changing the direction of the fibres to be better aligned with the loads felt by a quadcopter arm. AOS Arm Carbon is by no means a standard material. The layup is my design and custom engineered to be as close to optimum as possible for the application. I learned recently that the CF manufacturer I'm using is infusing under vacuum but curing in a heated hdyraulic press to accelerate the cure and increase the density of the final composite. Regarding frequencies, the frequecies of frame vibration ~200Hz are very much lower than the frequencies of the electronics ~1,000,000 Hz and the RF ~2,400,000,000 Hz so no risk of them interfering.
@@ChrisRosser cool thats interesting as i said your approach is quite high tech and the applied electronics/RF/control loops waveform form of mechanical engineering, what is that classification of engineer? Its like an energy engineer 😆 im sure thats a stress engineer in aerospace as you model the inefficiencies essentially. I visualised the separate bandwidths living happily within the frame, sorry can't shake the primarily mechanical gorilla mindset 😁. And you can push a more favoured resonance via the arm engineering to the gyro as you can't eliminate it, hence make it the better form to deal with, but to me means multiple seperate bandwiths, then potentially seperate mechanisms to serve the mitigational purpose, allowing people to invent and add to evolve our community design, for example soft mounting not found to help on motors so much etc. I see, you that are custom demanding the weave, thats a pretty specialised company you've found fair play. I thought maybe you'd found a little composites worker somewhere, maybe you can find or grow one from your community, then you could actually model a design beginning to flex your skills, with the cost of CNC and 3d printing its pretty viable and more the dangers of handling needed skilling so not very long to learn and our kwads don't need aerospace standards of certification. I actually could hook you up with Bombardier/Airbus approved composite outfit in U.K. if wanted but doubt any saving as aerospace and i know the cut throats that run it. I realise not your area regarding the investment of time or cost, but you are leading and actually i'd say lead UK educator and researcher for the engineering, which is a great contribution. So maybe your more mechanical followers might want to look to construction of composites, I actually feel we need to move past flat board designs, but of course that needs the industry at our little scale. I won't link as anyone can search but easy composites is a wonderful UK company that has amazing videos on UA-cam to educate anyone interested from simple designs to motorsport grade projects.
maybe 2 piece arms? bottom disposable 3mm section with grove for Nyogel. top section 3mm with Racewire in it maybe... I like pursuing both the best value and best performance (within reason) Broke kids needing a hobby need Value. others with some spare cash and or commercial applications want performance. the Tech rolls down hill.
I think a thicker single arm will always be better than a sandwich because of the increased stiffness. But I love the ideas and keep them coming! Definitely looking for best performance at reasonable cost with the AOS frames.
With every video his beard is getting longer. When will he finally transform into a FPV wizard? 😂
Amazing content, as always!
Lmao he'll yes
Maybe one day! I've got a way to go before I can challenge itsblunty 😁
It grows with every subscriber hahaha. Chris such a legend though, I hope he sticks around and one day does a micro frame of some sort.
@@slowentropy4531 I have a 3.5" frame if that counts as a micro?
@@ChrisRosser unfortunately it doesn't to me mate, its a great category don't get me wrong!! Here in Australia our limit is 100grams before alot of laws, rego and stuff are starting to really kick in. FPV is technically illegal anyways even on private land with hundred LOS observers in this country. So I've been just chasing to ultimate flying fun under that weight. To me once I go above 2.5inch I just go full size as sound attracts same amount of Karen's etc around.
Google wing delivery drone fly constantly over my house and my flying nature reserves they want us hobbyist out of there way asap.
Great video. Finally someone tackles carbon layup for FPV.
I always wondered why no one used 0,+45,-45,0 or +30, 0, -30 or similar layups for arms. But it seems they are not readily available as plates, so that may be the explanation.
We at Madkwads have done that since 2018 and I suspect Chris got the idea from us because I explained the concept to him in a private chat. After that he started looking for other manufacturers that could make plates for him leaving out the part with IM-fibers and TeXtreme spread tow fabric.
I remember Bob Roogi put us in touch early on when I spoke with him about optimizing CF layups. I know we spoke about simulating different layups in FEA and it motivated me to create the code I now use to calcualte the coposite porperties of different layups. Unfortunately the cost of Textreme (particularly for larger thicknesses) was prohibitive. Fortunately the tool can be used to optimize layups for any material set. Cheap or expensive!
@@ChrisRosser Yes, But we have reduced that now by investing in a high pressure press and a cnc machine. This way we can reduce labor and shipping cost that earlier was a big part of production cost.
Ah, feels like my materials & composites class all over again. Great!
I'm gald you enjoyed it and I hope you found the information interesting and useful.
@@ChrisRosser I love your engineering take on everything fpv. As a fellow aerospace engineer whose worked in the field , this is awesome.
Absolutely fantastic video! You are awesome and WE do appreciate your efforts.
Thank you so much! Knoweldge is power 🤓
I have flown frames from Madkwads which reminds alot of what you are talking about. They fly very good and have great durability. Also exceptional stiffness with just 2 mm arms.
I believe MadKwads use their own carbon fibre fabric "Textreme" which is certianly a high grade material but I'm not sure they have the layup optimized specifically for each part (I've been speaking to them about this as recently as a few months ago). The software I've written allows optimization of any carbon fibre material set so perhaps there is some overlap there.
@@ChrisRosser I have talked to Madkwads and to my understanding they have definitely optimized the layup for different parts of the frame.
@@ChrisRosser they most definitely have optimised the layup of the CF per part. I've seen the way they do it first hand. Reach out to Johan and Oscar and they'll for sure be able to confirm or deny this claim
@@selaI3 Chris literally said that has been speaking with them about this....
Back in the '80s I was a bicycle geek who was learning about the new-fangled carbon fiber frames that were coming to market. Part of the promise of this then-expensive-and-new material was the ability to customise the lay-up of the build. Here's Our Chris, fulfilling prophecy. Dang, ain't engineers wonderful?
@Grim FPV Not compared to the '80s. The stuff was scarce back then. Multiply Chris' price per sheet by about 12 and you're in the '80s ballpark. . .
@Grim FPV 1980s dollars, too. Be five figures in today's money. I shit you not.
I'm really pleased the cost didn't go up too much when customising the layup. Higher grade materials are 2x the cost for 20% more performance. Now we can get the same benefit with the cheaper material for only ~25% more. 😁😁😁
@@ChrisRosser See, that's why engineers have my admiration. You lot make 'miracles.'
Thank you Chris!
Finally! A real reason to add a new frame to my collection😎
Glad I could help! Check out the AOS 5R as it uses AOS arm carbon for the arms. www.cncdrones.com/aos-5r.html
Finally..well done !
You got it! I hope that this provides a big benefit for people with frames like the source one where they can get an arm upgrade!
Also provides material technology in this hobby:)
Hey, Chris. Solid video as always. My opinion on the t700 carbon is you should absolutely offer it as an option for the AOS frames. Personally, I would like to have all of the body plates be t700, while the arms remain t300. This is because I would rather snap and replace arms than ever have to replace a body or camera plate. I don't speak from any experience with frame design, so if what I said isn't necessarily correct, please advise :)
Good call! I'll speak with Nick about making it an option.
Great timing for this video. I just started working with carbon fiber last week. I plan to skin parts and make plates for frames.
Glad it was helpful! Good luck with your experiments.
This reminds me alot of what the guys at Madkwads is doing! Glad to see more people go that direction :)
Madkwads took the approach of using higher grade and more expensive materials to get more performance. The nice thing about optimizing the layup is it makes any materials set 20% better! So you can improve cheap CF and expensive CF as well without adding any material cost.
@@ChrisRosser
having helped production of MadKwads CF during a weekend I can assure you that they have put a lot of effort into optimising their CF layout. Just putting their achievement to more exotic materials is selling it short. They have done the work with material spec and it's layout, maximizing the performance to the expense of higher cost.
@@ChrisRosser Have you validated that claim thru mechanical testing in a scientific way?
@@selaI3 Yep, you are quite right looking back through my conversations with them I calculated their layup design added 30% torsional stiffness and 6% bending stiffness over standard layup.
@@madmanjohan Absolutley, the performance improvement has been validated with bench testing and flight testing.
Great video Chris.
Just couple questions for you.
1) What is the process to manufacture those cfrp? Is it standard room temperature vac bag process, autoclave or out of autoclave (OOA) method?
2) Did you use Unidirectional cfrp in your new design?
3) Why don't you use standard mechanical properties testing like tensile and bending stiffness?
Whatever it is, you did a great job and appreciate your effort.
1. The material is made exactly the same way as cncmadnesses standard layup by the same company out of the same materials only the fibre direction is different. I think its a vacuum infusion process and then cured in a heated hydraulic press.
2. AOS Arm carbon uses only Unidirectional carbon fibre in the layup to maximise the fibre volume and the straightness of the fibres. The UD layers are oriented in different directions to provide the right balance of stiffness.
3. I do what testing I can. I don't have access to expensive test equipment, I'm just a hobbyist. I do flight testing and blackbox to confirm the simulation results and my sims are currently within 5% of test results. This gives me good confidence in the approach but I'm not a big company, just one guy doing his best.
My thought on price for frame material is that since the cost of electronic components as gone up so much, the cost of frames is relatively low. Paying 85% more for the frame would still only drive up the cost of the build by around 10-15% assuming you are using premium components. If you took it further and only used the T800 for the arms, the relative increase of the build would be even smaller. So I would definitely be willing to pay more for more out of my frame.
Great reasoning. I'll see if Nick can make some higher grade fibres available.
Great new videos Chris. Definitely agree with the increased engineering on Quadcopter structures that opens up more room for the FC behavior to operate at a lower delay 👍🏼
Thanks! Glad you enjoyed it 😁
look forward to seeing the results of these efforts,
AOS 5R launch video coming very very soon. 1st frame with AOS Arm Carbon arms. I'm super excited to show it to you.
I'd love to see the performance of a crazy strong carbon like t800 or t1000 for the arms (both reduce the resonance and strength during a crash) with this weave method. And maybe a more stiff carbon fiber on the frame (stronger than 3k but also going to reduce a lot of resonance). It might be expensive as hell but it'd be pretty cool to see the results. I'm sure some people would drop $200 on a frame if it meant it was borderline invincible and flew amazing.
I'm working to make T700 available for my frames. T800 or T1000 is something that I might be able to do as part of special editions with limited runs due to the incredible cost of stocking the material.
Looks like what Madkwads have been doing for years with their CF, it really is stiff AF. Even a 2mm arm is pretty much impossible to bend 😂
I believe Madkwads achieve their performance through use of high grade and expensive materials. I don't think they do layup optimization for their quad parts (I was speaking with them about this a few months ago and they were asking if I could work with them on that). My approach uses standard materials rather than proprietary fabrics so its much cheaper and I think more suitable for mass production.
@@ChrisRosser layup optimization is 90% of what they do. The higher quality carbon they use sure plays a part but it's not as easy as just throwing more money on the CF itself to achieve what they have
@@ChrisRosser We do use higher grade material then most others but it is not proprietary. To reduce the cost and speed up production we have recently invested in a high pressure press and a cnc machine. This way we can reduce labor and shipping cost that earlier was a big part of production cost.
@@LongcatFPV The layup is not a major contribution in stiffness and bending strength in cf mechanical properties. The process such as higher pressure curing machine and hi-stiffness material (obviously expensive) is the major contribution.
If you said 2mm is hard to bend, it is 90%+ manufacturing process and material.
*Just got little experience in manufacturing and testing cf panels/parts for A320, A350, B787 and A400M.
@@madmanjohan Thanks for clarifying that Johan. From other comment threads it sounds like you do layup optimization for each part. Do you use different layups for arms and plates?
love the fpv specific material science. I work with high end carbon bicycle frames and love to see the effort to push fpv frames into that realm of manufacturing. I want to see a molded carbon fpv frames and parts. Like the Iflight morgoth! I liked mine it was low drag and light weight but broke very easily.
Outstanding idea. 5mm is the thickness I would be most interested in.
5mm is already in stock at cncmadness if you want to have some arms cut to test. It works best for long thin and straight arms.
The Racer X FPV frames are T700 and I've had less filtering with these frames.
I am currently running modified stackups for the arms on some of my quads. Also toyed with rohacell-cored material and an extra skin to regain torsional stiffness. Also made a frame with tubular arms.
They all are far better than plain 0/90 regarding bending stiffness and ultimate strength, but the drawback is lower crashability.
In the end the crash energy must be distributed through the frame to keep it in one piece. Maybe more elongation before break would be better. Aramid+glass seems promising
That is probably because rohacell can't handle the shear forces in the center of the laminate. That is also the reason why anisotropic laminates can handle more load. In a 0/90 layup you normally end up with delamination in the center 90deg layer because in that layer shear forces are highest and all load has to be handled by the resin. Aramid and glass are/can be just as strong as carbon but they both have far lower modulus. That is why we all use carbon - it's stiffer. The other downside with glass is that it is heavier.
I would, but I would definitely would if you used different material on different layers. What would be ideal would be semi quasi-isotropic (biased for 0deg) layer-up using an alternating combination of M30Sc (int Modules - 294Gpa\5.94GPA tensile modules\strength) and T700 (standard Module - 235Gpa\5.3GPa) layers. This combination would give the best stiffness and strength for the price and will as this will raise the resonance frequency significantly.
I also believe the outer Weave can make a significant difference. For example, Textreme Spread Toe used as the outer layer is far better than standard twill for dealing compression and expansion forces.
I believe the Karearea Tora uses T700 CF
I look forward to something like this being available in 5mm or 5.5mm thickness for my AOS 5.5". (Fingers crossed)
It's a great idea! Using different materials for different layers would be a big change to the manufacturing process and might add a lot of cost needing extra reels for the different materials and extra QC for verifying that the right material was used on each layer. It would probably be cheaper just to use a higher grade fibre throughout to keep the manufacturing simple.
I would be interested to learn why textreme is better than a standard woven fabric for the outer layer. I guess they are using a higher grade fibre so the material is stronger (but also 2x the price!) A spread tow weave is pretty common for CF and makes the outer fabric layer thinner and gives a different look but I'm not sure there is a mechanism to give an enormous performance benefit.
We at Madkwads do use T700S for the middle of the laminate to build thickness and M30SC on the second outermost layers where they make the biggest difference to performance. There are several advantages to TeXtreme. One is that it is much thinner so for a set thickness, say 5mm, you can fit more T700 and M30SC UD layers that improve the perfomance compared to a thicker 3K weave. The angle the fibers have to take to get over eachother inside the weave is much lower compared to thicker weaves. This improves the compression strength of the weave. Finally - it looks spectacular! With a mirror finish on the plate it is just stunning.
6mm arms 💪
Cool, don't forget to vote on the poll!
Oh this is the stuff madkwads uses! They are the absolute best in the carbon game! We use their carbon on our frames and its game changer. How ever is that stuff not proprietary. I know they make stuff for huge car brands and more.
Madkwads have their own carbon fibre materials set and its quite a lot more expensive at around 2x the cost of standard CF I think. This is a layup optimization so it can be used with any grade of CF from any manufacturer that can make standard layup. This makes it potentially much more economical for mass production.
@@ChrisRosser yeah well I have used theirs and its done wonders for my frames. I dont mind spending a bit more to get the absolute best. But I guess many people here want to be cheap and get stuff as cheap as possible. Since I like to have stuff that lasts i dont mind paying 100euros for a frame when its much better then the 50€ frame. Its all about how long will it last and how much less time do I have to spend on repairs. Also they have been doing this for so long they know their stuff. I would recommend them to any one who wants stuff that lasts and not who wants the absolute cheapest way to get something sort of like it ;-) But cool that your talking about new types of carbon. Its always interesting.
When an aerospace-engineer friend visited me and stared at my quads, his first question was "why aren't you using carbon specifically aligned to the arm directions? I feel there is a bit of potential left here." I couldn't answer better than just saying "yeah, they just cut it out of standard sheets." It seems he was right after all ;)
Now you can buy a frame that is made that way. The AOS 5R!
@@ChrisRosser I'm gonna try that one in a firstie-racing rig next year :3
I've made a lot of custom racing frames. I've broken a lot of these frames. T700 is the best - it's a lot stronger - you can cut about 30% of your arm width using it and get the same durability as T300. What I would like to see for racing frames - isn't strength or stiffness - but a material with a much greater plasticity - where it can take a hit and not break or turn into a "noodle arm". All my race frames a 5MM. There are some really interesting composites that an aerospace fabricator had scrap of that I never dived into - PEKK and PPS composites.
I'm working on bringing thermoplastic carbon composites to FPV. They have most of the strength of epoxy CF but are much more durable. They bend rather than break and you can straighten them out with a heat gun!
Yes on 700 or 800 have two aos frames and would upgrade for sure
Cool. I'll speak with Nick about providing it as an option.
would love to see the resonance analysis of carbon tube arm quads. it's cool how tunable carbon pipe is just by altering the weave a bit
also, using a core material. seeing as the inside layers are kindof useless anyway
Carbon tubes are very challenging to simulate but perhaps I could extend my code to calculate them, a big project though to be sure.
I developed a frame where the lay-up and shape is optimized. I used T700 UD / T700 Twill / Inegra and Aramid in later versions. Commercally it was impossible to get get any profit out of it (even at $119 for a frame) but it was a very nice (but expensive) hobby project. From an engineering perspective I think you would like it very much. I still have a few laying around, if you want one let me know I will send it out to you.
That sounds very cool! I would love to see a photo of it if you have one 😁
@@ChrisRosserI will send you some pictures, I tried to link a website here but apparently that is not allowed.
ill be interested to see the crash data on this and how the very separate layers although joined, act on impact. as the 45 deg. layers are sandwiched in the middle i will be curious to see how they delaminate on impact. I would assume that having the 45deg. fibers be spread out more uniformly in the layers would provide superior strength then them being positioned only in the middle {ie quasi isotropic), however, this is an assumption based only on my limited experience i am not a schooled engineer.
Yes, I am interested to see how these arms break when crashed really hard. You can be sure that if there is room for further improvement I will adjust the layup design!
As far as I am aware the 45 degree layers are best placed in the middle because they have the same effect on stiffness wherever they are. The UD layers are better further out so they go on the outside. Quasi isotropic is a sepcific layup with 25% 0/90/45 and -45. AOS Arm carbon is an anisotropic layup not quasi.
I'd buy some for my Chimera 7
I'll try and make the right thickness available.
Yes please Chris!
I love my AOS 5.5 and build the Falcon 7 right now ...
As next project I would like to take on your AOS 7 Mantis.
If you offer frames in higher quality CFRP would be really great! 👍🏻
Also I would love to have forged carbon on the outside for cosmetics. 🙏🏻 please
Maybe an option to choose between satin or high gloss finishes would be nice especially for forged carbon finishes.
Do you think this might be possible to request to your supplier? My understanding is that they custom cut for each order anyways, hence there should be no issue with slow moving or dead stock when offering more options.
Hi Matt, I'll certainly look into it for you. You can always ask Nick yourself when ordering an AOS frame from CNC madness if he can use a higher grade. It really depends on what material he has in stock as its stocking a material that costs money (both to buy the material and the space to store it).
@@ChrisRosser Thank you Chris for the quick reply!
Do you think the forged carbon option is possible?! That would be really great!
Have a good day!
@@ChrisRosser Dear Chris,
I was reaching out to Nick under the mail address you shared above. Unfortunately I could not get a reply.
I really would be happy to have the forged carbon option. The option choosing higher quality carbon for my AOS 7 build would also be nice.
I am waiting to order the frame and hope options are made available sometime soon.
Thank you for all your time taking a look at this. Have a good day!
Great video Chris. I would like a 7" dead cat frame for video work? not able to see the props and use the DJI air unit, will you be making aframe like this?
The AOS 7 and AOS Falcon 7 both have no props in view. Check them out!
@@ChrisRosser Thanks Chris I certainly will check them out.
Lots of great info, thanks. Have you looked at using kevlar in the stack?
I haven't looked into Kevlar. Because Kevlar is less stiff and less strong than CF you wouldn't want to mix them. The stiffer CF fibre would end up taking nearly all the load. The failure mode of kevlar is more stretchy so it might be more durable in crashes.
As always i got a lot to learn about what carbon fibre is and what one can do with it.
it serves for very good morning motivation for me to learn more about technology and sets me up for a day full of scientific discoveries
about things around me.
Added to all of this I have always wondered why do companies cut frames from different sheets of carbon
and why not mould them into shape like how top supercar companies like koenigsegg kind of bake individual parts.
Does it add more labour into the process that way? is it good to waste some material and reduce labor that way ?
Moulding carbon fibre is very labour intensive and labour is a huge part of the cost of carbon fibre parts. Also you need to make a mould for every part out of aluminium which is tremendously expensive. With flat sheet you can cut out any part from the sheet with no tooling cost.
Im up for it
Thanks! Up for better carbon? I'm working on it with Nick.
Hey Chris, is there any chance to make arm carbon standard (or optional) for all AOS frames.
Or more specifically: as a standard (or option) for the AOS Falcon frame?
It is something I'm actively looking into. It will take some time to get manufacturing set up for the material. At the moment I only have 5mm in stock at CNCMadness.
@@ChrisRosser that would be awesome, in that case I have no doubt what frame to go for for my upcoming 7" LR build (referring to my comment on the other video).
Please let us know if/when it is implemented on the AOS (Falcon) Frame(s)!
Chris excellent video as usual! Iv’e noticed that %95 percent of the quadcopter arm frames I’ve seen are solid carbon fiber. If one wanted to use T800 or T1100 carbon fiber wouldn’t it be beneficial to adopt a design for the arms with a hollow center to run the motor wires through? This way the aerodynamics will increase and in theory be similar strength to a solid rectangular T300 or T700 carbon fiber arm with less weight 🤔. I’m not an engineer but it was a thought that ran through my head for additional weight savings.
Hollow arms are a great idea and some larger quads do use tubular CFRP. However, the mounts for the arms are very heavy so its not beneficial for smaller frames. Also tubes are very stiff but not super durable compared to solid CF. For quads that must crash well solid CFRP is much better.
@@ChrisRosser Thank You!
Now that arm cross-sections are getting squarish, is it time to use hollow tube arms to save weight and maintain rigidity in a 5" quad? Also since carbon is conductive and can block transmission from short antennas, should frames be made from S2 glass?
the issue with tube arms is mounting, performance wise they would be great, but they are much harder to incorporate into the design of a frame and also come with manufacturing challenges.
Hollow arms are tricky. You risk crushing them in the mounting and the mounts tend to be a lot heavier and more complicated. Definitely useful for big quads (X-Class) but not so much for little ones I think.
Great insight into the process. I had some idea and this helped. Would really like to see the science behind those formulas, but I bet they are very secretive.
I put a lot of work into the software that calculates the performance of the layup. If you want to learn more here is the lecture course I used to learn what I needed to know to do this: ua-cam.com/play/PLREHQnoFMsHAuaShRdNQ1-tsE_r8qS6dh.html
Bring the upgrades I'll buy.
No problem, I'll speak to Nick about offering it.
What do you think of building a carbon-carbon sandwich plate with T700 on the outside where it is most benefitial and T300 in the middle?
The problem is that T700 or more or less any other fiber that is stronger then T300 are not made in 3K (3000 filaments in each tow). T700S is most common in 12K and if you would weave that it will be very thick and full of pinholes. The waviness would also reduce compression strength alot. The solution is to use spread tow fabric like TeXtreme because then you can use the stronger fibers that are only manufactured in 12 or 15K and still have a fabric that is half the thickness of a 3K fabric with T300. That is one of the reasons we only use Textreme as outer layer in the laminates we make at Madkwads
@@madmanjohan Thanks, I did not know about the availability of T700 fabrics. So do you think betafvp uses lower grade carbon for the outermost layers on their frames advertised as using T700? Spread Tow fabrics are great, but if I remember correctly, quite expensive. So I don't think using those is warranted in a more cost focused carbon layup incorporating a lot of T300. Maybe one could use unidirectional carbon to have a visual distinction for the "arm carbon".
But I think maybe I was not clear enough what I was going for. Assuming pure vertical bending, and assuming the cured layers behave like the fibers (same stiffness, T300 has 70% of the strength of T700) you could use T300 in the center 70% of the plate and use the stronger fibers only on the bottom 15% and top 15% of the plate. This would result in a plate with the same bending strength as a plate made only from T700. To be safe, and to account for other loading directions, I would use a 40/60 or 50/50 fraction of T300 and T700. Of course this calculation is simplified but I think you get the idea.
This is probably most useful for thick arms. The thinner body plates are loaded more in tension and compression (and not bending), at least where they sandwich the arms. So i think it is better to use only T700 or IM carbon for those. For these thinner plates the material cost is probably relatively less important considering labour and machine time, anyways.
@@LS-xb2fh Yes, when claming T700 lamintes most manufacturers referes to the UD layers.
Spread tow is more expensive but our goal is not to make a cheaper laminate. If low cost is your focus then go for Chris laminates.
A laminate without a weave as outer skin is far more sensitive to impacts. If that does not concern you then you can go without it.
I understand what you are going for and that is what we have been doing at Madkwads since 2018 - just one notch higher in grade all over. Instead of using T300 as the cheap fiber in the center we used T700. Instead of using T700 as the outer UD layers we used M30 that is a intermediate modulus from Toray with similar performance as T800 but more impact resistant. This might not be what you are after (to expensive) so Chris concept might be better (cheaper) for you.
One thing to keep in mind is that carbon fiber have only 60% of its strength in compression compared to tensile load. Another thing that make big impact on both price and performance is layer thickness of each UD layer. Many thin layers perform better but are also more expensive to manufacture.
@@madmanjohan I appreciate your in depth answers. Your composites and frames absolutely look great. But I think for most people the very highest quality is not worth it. Most would rather spend some extra grams than extra dollars to get the same stiffness and durability. So I think for higher quality composites to be widely successful, they need to be not that much more expensive (and marketed well, like calling it "arm carbon"). Edit: And with higher quality I mean better fibers, an optimized layup and a combination of both.
I hope that in a couple of years all but the cheapest clone frames will use at least a somewhat optimized layup for the arms, and higher carbon fiber grades will used be at least somewhat more often.
Additionally, replacing some TPU parts with Formfutura Pegasus PP ultralight might be a more cost effective way so save weight, compared to going for the best carbon. It has a density of 0.75g/cm³ (TPU: 1.2g/cm³) and is adequate for a lot of applications on fpv quads. Regular PP is fine too at about 0.9g/cm³. Edit: This way to save weight is useful at least for freestyle frames, which use way more TPU than race frames.
A point that is worth making is that optimizing the fiber layup provides increased performance for all materials. So if you use a more expensive material and optimize the layup you still get +20% more performance on top of the benefit from the better material. You don't have to do one or the other, you can do both.
For internal layers I think UD fabric is the way to go. You can use any grade because tow doesn't matter and you get the best performance. I think the outer layer on a 5mm thick arm is mostly cosmetic. A woven fabric might look nicer but I'm not sure it gives much performance benefit.
AOS arm carbon uses UD for the outer layer for one very important reason. The orientation of the parts is paramount. You MUST cut them aligned correctly. Having the outermost layer UD and aligned with the strong axis allows the machinist to easily confirm which direction is the strong direction with one look. This minimises the risk of parts being cut misaligned.
Been using CF in rc myself for years...vac bagged wing gliders and planes , boat hulls , cars..etc...I agree with all that was said and will add that I find some CF quad frames to be laid up way too lean almost starved of epoxy in places...epoxy costs money but so does a bad reputation...
Absolutely, you want to have enough epoxy but not more than you need. It's a difficult balance to strike but that's why good CF costs money.
what you think about carbon tube ? like whats on some of those big drones the arms mainly
Stiffer but less durable than solid carbon. Also the mounting for tubes are very heavy and complicated which makes it less suitable for smaller drones.
if this special carbon is better then what we normally use can we get away with using thinner carbon for the frames? as it is now a 6x12mm arm on a 5" is all but indestructible.
Yes, absolutely. You should be able to make the arm 20% narrower without loss of strength or stiffness and save a bit of weight in the process.
How is the UV properties of the ARM carbon's resin?
It uses the same resin as regular carbon fiber if that helps?
Way to go mister Rosser I'm extremly interested in this I would like to see how this turns out would we be able to order arms for any quad using this aos arm carbon ?
Yes you can! You can order from cncmadness.com currently we have 5mm in stock but hope to add more soon.
is aos 5.5 are on T800 family or T700 familiy,,,help me sir ,,,im using aos 5.5 and flew very good & rigid
I've got a feeling I'm missing something obvious regarding the different layups.
Both Standard and Quasi Isotopic layup use a 90 degree offset between directions. Why is this stronger than using a 120 degree offset? Or is it more ease of manufacturing cost/benefit?
Hexagons are bestagons, but with Carbon Fibre it's all based around 90 degrees. I'm sure it's been tested and found inferior, just curious why.
Great video as always, love getting a glimpse into the nitty gritty of the incredible materials we use!
" Both Standard and Quasi Isotopic layup use a 90 degree offset between directions." -- wrong. besta rewatch the video.
You are right. The other (and better) way of doing quasiisotropic layups is 0/60/-60deg layers. When we at Madkwads built out own press and started making our own laminates in house, we could easier play around with fiber angles. We then found that 0/60/-60 worked better then 0/90/45/-45 for the midplates in our MAD-LITE frames. It is not a universal solution but in our case it proved to be better
@@madmanjohan BTW do you guys sell sheets of your special CF layups? I'd love to use it for my own frame designs.
The 90 degree offset is simpler to manufacture I think when making a rectangular sheet. The best fibre orientation depends on the loading case for the part. So there is no best layup. AOS Arm Carbon is the optimum layup but only for straight quadcopter arms!
There must be CFs that have better vibration absorption than others.
blend in some Nyogel in the resin Matrix.... (i have no idea If i'm using these terms correctly. smack me down appropriately)
I'm thinking of joining two 1.5mm babytooth frames with some sort of Viscoelastic Damping adhesive,
maybe same for joining 2 3mm arms for 7"?
the test needs to be...
same frame design...
Cheapest CF, Best performance cost no object (within some reason)...
then bang for $$$
Does it perform better.. last longer... how much soo?
The layup though is where the real magic is from my understanding. From watching F1 suspensions over the years...
think most of the tuning is the directions of the layup.
Using a 3mm arm is better than combining 2 1.5mm arms. It is way stiffer, so the resonance frequencies are much higher. And not having low frequency resonances in the first place is superior to highly damped resonances (which is better than low frequency resonances with low damping).
L S is right that one thicker arm is better than a sandwich because shear stress needs to be transferred through the material and that doesn't happen with a sandwich. The grease is always going to work best at the joints between parts because that's where the most movement is. The arms themselves don't move as much (I've tested viscoealstic tape on the arms and it doesn't work as well as greasing the joints with PG44A). Layup is definitely the way forward because it helps cheap and expensive CF just the same.
Yes, clearly willing to pay extra for an stronger and stiffer carbon. Take my money!!!
Right on! I'l work with Nick to make it an option.
Isn't your aos arms also in different directions? Planning to change that design?
The truss gives much more benefit than the material change. The AOS 7 uses a split truss design that might be amenable to AOS arm carbon. I will definitely be using the material where it gives a benefit in future designs.
@@ChrisRosser I guess this would just be an unnecessary cost increase, but maybe you could make a layup where some sheets are inline with one of the struts and other sheets with the other strut.
Wanted to say Great Job on the AOS series. Right now I have two 5" frames; the BotaFx by Bot Grinder, and the Switchback from Evan Turner. I listed them because both are top frames in their respective disciplines. Your AOS frame (for me at least) is one more example of a frame meticulously designed with a purpose. It inspires me and I will be building my next drone on that frame. Thank You for your contributions to this hobby. (also don't mind Mr. Steele he had his mind made up before he flew it, everyone has off days)
I'd love to know what Emax is using on there 5inch racer arms to make them so stiff.
To compared my mates switchback the arms are so strong, I'm still yet to break one in a crash. At races they have metal poles and yeah it's a test for strength haha. After a year of crashing the end is starting to Frey a bit though. But probably flown 500 plus packs half of which a crash in the flight of some kind haha.
Looking at photos it looks like the arms are relatively beefy and made of aerospace grade CF (60/40 or better fibre volume) which will make them very strong.
@@ChrisRosser makes sense mate, I've always wondered about it. Tried a few different tight race frames and it blew me away the strength they got with the simple design, especially as its an old frame now. But I'm saving for one of your frames as I'm really genuinely impressed by all levels of thought and time you've put in. Thanks again mate and I do hope you stick around in FPV into the future and don't get burnt out by some of #&%! that comes in hobbie for designers and innovators.
Cheers.
@@ChrisRosser You can't tell resin content fraction by looking at an image. However you can tell by measuring it's density.
Aerospace grade is just a certificate - it does not mean it stronger in most cases. T700S sold both with and without aerospace certificate and they have the same property's.
@@madmanjohan Always learning on this channel, even in the comments. Cheers mate, what ever they done they made the strongest arm I've used on a 5inch racer quad.
@@slowentropy4531 if you ever break one - set it on fire, then peal it apart layer by layer and you will see how they did it
I think I would think of paying more for a more durable and little stiffer fiber, if the quad could have sth like 20g less weight or so
I'll see if Nick can make it an option!
Yeah can try t700 , I guess foxeer aura frame uses t700 so t700 may be a good choice
are you sure it t700 ? did you check it ? in this ridiculous market you can't tell what is what.
In the market everyone said they use T700, but indeed T700 is very rare especial in such cheap price
Id definitely pay more for a frame if its proven to be more durable and stiffer
If you use a higher grade fiber the frame will be stronger and stiffer. The only downside is the extra cost. I'll speak with Nick and try to get it added as an option.
Would you be able to show the actual design details without hurting your plans to sell it? I'd be curious to see how exactly you achieve these figures. Thanks!
The concept is called anisotropic layups. The short explain is that the laminates have a layup that similar to a quasi isotropic laminate but with the 90deg fibers removed. Instead you only have fibers in 0, 45 and -45deg direction. We made a video about this two years ago where we try to explain the concept ua-cam.com/video/_WGNU6tphYI/v-deo.html
Johan is spot on but the real key to AOS arm carbon is the *balance* between the number of 45 degree layers and 0 degree layers to get the right mix of torsional strength and bending strength for the quadcopter arm application.
+1👍
I am a huge supporter of t-700 carbon frames they just take a beating like t300 can’t. Hint personally tried t-800 but for me I’d rather pay more and have way better durability. So my vote is yes AOS frames should be offered in T-700 and or T- 800
Cabon faiba!
Thank you Chris for your work. Seeing a new carbon with less flex makes me immediately think of airplanes. Not RC ones, the big ones. That should be an interesting industrial avenue.
Second, it could also be of value for ultra light toothpick style frames. I really like the work Diatone did when creating a frame made of squares. It increases the stiffness while not impacting weight. Now if your style of carbon sheet can further slim down arms… That would be heaven 😉
What I have done is standard practice in aerospace, automotive and cycling industries, even high end golf clubs have optimized layups. Just trying to bring the tech to FPV 😁
I would get arms for my AOS-5 and 5.5, stronger and stiffer oh yeah.
I'll definitely see how this new material can be applies to truss arms. The AOS7 uses a split truss, I wonder if that could be applied to the AOS 5 which is much smaller...
Your timing is amazing. My friend just bought a table top cnc mill with the intent to try cutting our own frames, arms, etc.
That is awesome! Drop me an email if you want a sheet and I'll see what I can do.
That feels to me as if you just posed as some kind of composites engineering guru to plug your arms.
I would not claim to be a guru, just a professional engineer with training in materials and composites. Optimizing fibre layups is pretty standard in automotive, aerospace and cycling industries. Even high end golf clubs are doing it nowadays. I'm just doing the same for FPV quadcopter arms and making the material available to the community so you can cut your own designs from it. I think that's a good thing to do, rather than keep it for myself.
@@ChrisRosser I actually misunderstood what you did. I took it you used your software tools to select a set weave and preformed plate albeit higher grade and cutting arms etc, but adding a bit of educational razzle dazzle to fox the customer, my bad.
If you're engineering them that's fair play and I'm as I guess your generalisation would be a stress engineer no? A good person for it, can't you make props quiet next?.
I'm super defensive of real engineering and engineers that actually engineer at the moment sensing extinction ((and it can be software to stone masonry in my books) and because an academic/scientist only makes the transformation to engineer, by engineering something 😆 not holding the certificate, i see more potential engineers in the FPV community, whether as a blend of pilot and technicians to fly and maintain or more exciting, a place for the pure engineer builder, credited for now or not.
Maybe a place for our kind once again to invent and engineer in the world or how else can it manifest? and we should grow and build especially nationally.
Theres a massive boom coming that might be remote aviations niche, we would be the remote aviators then lol.
Or mass imports will fill any void which we might scrape off the 40 billion growth predicted and I see you are helping those engineers so fairplay.
As an aerospace engineer that saw the a400 EIS at airbus military R&D nearly 20 years ago and more recently a couple Italian M346 prototypes, those being mostly composite I'm a little educated.
From a practical standpoint I might suggest that if you control the layup you also have control of introducing techniques such as instead of only vacuum perhaps you could engineer a press and gain greater densities,
If then have a hot press could composite/laminate anything in kevlar is instant safe option but not sure qualities, surely and maybe combo with 3d printed moulds to allow pockets of foam or sorbothane etc in the arm, not too tricky to industrialise small.
Also its a smart direction you are taking by stiffening everything to gain high frequencues that are more easily squashed by cancelling it essentially as gyro noise, but as an evolution, might it not mess with other high frequency RF or nav functions when they need the precision/clarity? I guess they are damped at source then but maybe combing electronic and mechanical dampening also serves?
@@DigitalArtisan77 No worries. Easy mistake to make. I'm using standard fibres and resins but changing the direction of the fibres to be better aligned with the loads felt by a quadcopter arm. AOS Arm Carbon is by no means a standard material. The layup is my design and custom engineered to be as close to optimum as possible for the application.
I learned recently that the CF manufacturer I'm using is infusing under vacuum but curing in a heated hdyraulic press to accelerate the cure and increase the density of the final composite.
Regarding frequencies, the frequecies of frame vibration ~200Hz are very much lower than the frequencies of the electronics ~1,000,000 Hz and the RF ~2,400,000,000 Hz so no risk of them interfering.
@@ChrisRosser cool thats interesting as i said your approach is quite high tech and the applied electronics/RF/control loops waveform form of mechanical engineering, what is that classification of engineer? Its like an energy engineer 😆 im sure thats a stress engineer in aerospace as you model the inefficiencies essentially.
I visualised the separate bandwidths living happily within the frame, sorry can't shake the primarily mechanical gorilla mindset 😁. And you can push a more favoured resonance via the arm engineering to the gyro as you can't eliminate it, hence make it the better form to deal with, but to me means multiple seperate bandwiths, then potentially seperate mechanisms to serve the mitigational purpose, allowing people to invent and add to evolve our community design, for example soft mounting not found to help on motors so much etc.
I see, you that are custom demanding the weave, thats a pretty specialised company you've found fair play. I thought maybe you'd found a little composites worker somewhere, maybe you can find or grow one from your community, then you could actually model a design beginning to flex your skills, with the cost of CNC and 3d printing its pretty viable and more the dangers of handling needed skilling so not very long to learn and our kwads don't need aerospace standards of certification.
I actually could hook you up with Bombardier/Airbus approved composite outfit in U.K. if wanted but doubt any saving as aerospace and i know the cut throats that run it.
I realise not your area regarding the investment of time or cost, but you are leading and actually i'd say lead UK educator and researcher for the engineering, which is a great contribution. So maybe your more mechanical followers might want to look to construction of composites, I actually feel we need to move past flat board designs, but of course that needs the industry at our little scale. I won't link as anyone can search but easy composites is a wonderful UK company that has amazing videos on UA-cam to educate anyone interested from simple designs to motorsport grade projects.
maybe 2 piece arms?
bottom disposable 3mm section with grove for Nyogel.
top section 3mm with Racewire in it maybe...
I like pursuing both the best value and best performance (within reason)
Broke kids needing a hobby need Value.
others with some spare cash and or commercial applications want performance.
the Tech rolls down hill.
I think a thicker single arm will always be better than a sandwich because of the increased stiffness. But I love the ideas and keep them coming! Definitely looking for best performance at reasonable cost with the AOS frames.