I put some steel cable on a quad... 

I can only second that!. We bought a dozen toothpicks for our group and they are to this day our most flown rigs.

​@@BloodyJMF I'm getting close to considering an HD toothpick deal soon I hope. The components are getting really good. These dampers will definitely be involved with that one. I just wish the aio boards weren't so darn expensive these days.

@@Kabab I'm kinda lucky we bought them in packs of fourty from JHE back when. Since we never really managed to break stuff we still have them together with all the replacement arms xD

And yet only has 47k followers

@@JbVest the best 47k followers out there.

Unfortunately a lot of that has to do with how the world has just halted for the past 3 years. At this point I wouldn't even say it's a result of COVID. I would say it's more so as a result of both of our idiotic governments. Unfortunately small businesses end general developments suffer as a result

​@Kabab not to mention studies that are confirming cognitive issues are more than common after a Covid infection. Some level of brain damage comes along with every

​@KababFPV true glad you said what alot was thinking

Also on a break and being gaslighted from this! Got to the point where I was burning flight controllers out once a week bc of bad gyro QA. Not sustainable

@@Kabab hey buddy, i spent a couple decades building digital models of acoustic musical instruments. i've designed micro frames like the deculture fuxxor but you know everybody wanna be famous. ..understanding waveguides, take some of your carbon and cut it into strips or use plates and measure the impulse response over distance. the reason is, very simple models of acoustic instruments focusing on only the lower partials are "often correct enough," so if you design a frame by having solid data about the impulse response of your material so you can design at least the first order responsivity of the dimensions, you can at least improve upon the most elementary criteria. but seriously, you go about it all wrong like everyone else. if you want to minimise vibration, don't clamp it on with a steel U bolt... use dental floss. if there's no mass, there's no vibration. glue and dental floss will actually make an awesome lightweight frame and it has all the tensile strength you could want. yeah i wish some people had spent time listening to me instead of trying to be the next instant celeb. i tell people useful stuff. like if you need to code a cepstrum from your fourier analysis, just run another fft on your mag10'ed mag bins :)

😂 I always use BB. I just don't put a whole lot of effort into dissecting it because it reminds me of my organic chemistry lab exams where we get a similar graph and need to explain which molecule we're looking at which was so annoying....also because you can go so deep into it and I'd rather focus on high level ways to get things working right without fuss. I use your presents in BF all the time. Sometimes they match right and it's better. 👍

@@Kabab yeah it is just a good tool. Don't be shy. Embrace the obsession. My take is there are lots of frames out there that work well for vibration across all the quad classes. If we narrow to 5" class, that probably has the most: Apex, Martian II, Trans Tek Laser, Source One, etc... The gist I'm gathering is you want less weight and that is then where the vibrations creep in? OR I think you just have some engineer in you, because this video is like the engineering method 101: design, build, test, measure, modify, repeat. Tools like finite element analysis can shorten the cycle, but can take the fun out of it when the hobby is the method, not doing the finite analalsys in front of a PC; which then also needs real-world validate (is a part of design step). Mark Spatz, P.E. (licensed) (in good company here 😎)

​@@uavtech I definitely prefer and enjoy the build-test approach. Moreso because I learn a lot more about other things than just what I'm trying to focus on. FEA is helpful but is a very sterilized approach which doesn't always lead to the right result. That and I'm definitely looking for a way to drop weight. 20g less with comparable or better vibration management is gold to me.

​@@Kabab 100% Enjoying your work!

@@uavtech Really is amazing how well the source one v3 performs stock and its even better if you move to 6mm arms its dead quiet in the bb. I've got some far more expensive frames that resonate all the way up to 300Hz.

I'm hoping it's really as simple as moving through FC to the top plate and we instantly all get ~20% damping right off the bat

@@Kabab I guess one can make a simple test by printing some lipo guard, sticking it on top of the battery and just duct taping the FC to it. Not production ready solution of course, but should be enough to estimate if this particular spot gives better results.

I don't use an ND for vibrations. I use it for the actual ND effect to get motion blur

@@Kabab which i can totally appreciate as cinematic pilot. and thats the ONLY way NDs should be used for. but lets be honest 90% say it helps with jello which is right but only like 50% and its a patch for an entirely different problem. anyway as i said i am happy to see others trying to deal with the actual vibration problem instead of just use other tools to cover it. good job

In this specific case, it's not quite consistent with your findings with your application. I have tried to make arms from HDPE and a number of other materials as well as sandwiched materials and many other options just to run into low frequency wobbles and resonance which is the very worst kind of vibration for this application. I do hear you completely however and will try something else you may be intrigued to see in the future.

That's where I'm heading it's just that from CAD to frame to fly is like, weeks in between....still gonna give it a shot with the next one

Yeah that's an option but it suffers from the same issue as anything else between carbon. You bolt it together to try and keep it strong which negates anything between mostly

Some damping grease may help that craft from an early death.

@@Kabab I guess I should try 🤔

That would be really nice but we're working with a weight restriction here. It costs a lot in weight to make different components inside. Especially for the battery. It's also very difficult because no battery is the same size and they change size over their lifespan too

The single greatest contribution to the industry imo. Black out mini H. Just so ubiquitous with the early industry and classic.

@@Kabab Reckon you are doing your fair share to make a big difference too. Not to mention improving FPV pilots orsl hygiene 😬 I hope BlackOut reads this encouraging message.

Yeah this video is a little more advanced but you'll understand it after you build maybe your third quad. It'll all become obvious

I literally put a video up on that this morning. All those claims are false by MIT unfortunately but the overall prop design that was made may not be a total waste. See the video I put up this morning

@@Kabab Oh okay. Thanks.

@@Kabab I watched it. That kind of propeller design is a whole new area to experiment with and make videos. About frames: Have you looked into making frames with a biomimicry structural design? They are of course difficult to design and produce, but I think that method would solve your vibration issues, as well as make them lighter. Another drawback is that you'd have to add plastic skins over them to reduce drag. (I looked through most of your video thumbnails, and I didn't see any.)

That's my expectation

That's what I'm hoping is happening...we'll see

This is also what I discovered while prototyping, interested in the results between the different position on the H frame because of the shorter arms

That's where the H frame theoretically makes sense. However I think you'll loose a lot of stiffness and overall rigidity in the whole structure that it creates new problems like lower freq vibrations and more critical resonance modes. So trying to balance that trade-off, you kind of end up with the standard X frame. Just my assumption. We'll see how your test works out

@@ariafpv It's less about X or H shape and more about the interfaces between parts IMO. I'd first focus on building a rigid structure for the arms and motors to have a solid foundation. From there you work backwards and come up with a clever way to decouple that from whatever part your FC is mounted to. The FC mount doesn't need to be strong in itself, it just needs to hold in it's place.

@@KevPV yes kind of what I meant. With X style I was just refering to a standard layout creating a rigid core in the center (opposed to the H frame he showed). Doesn't need to be the usual 4 interlocking arms. As you said the goal is to only have the FC be "decoupled" from the rest

Something like that is always helpful but the FC is so low inertia it can only resist higher frequencies

Yeah that's why I'm considering doubling up on dampers just to test but I could never run with that because of the added weight.

We've been clawing at the surface for over a decade now. There's no surefire way to get any sort of hardware damping consistently. Vibration isolators don't work for anything above 3" it seems. I'm guessing the amplitudes are too high when the prop size gets bigger.

@@Kabab I agree, this problem is not easy. I would like to see more of a focus on the frequencies that mater to the FC and what it’s just ignoring. From my understanding, we want to focus on the low frequency flight maneuvers and prop wash frequencies. When the vibration gets to the FC(gyro) it should be cleaned up from motor noise, frame resonances, etc. Most isolators aren’t going to do that well, the simple rubber ones are going to isolate at higher frequencies and maybe not in the correct axis, and if they do isolate at the proper frequencies they are likely to remove the important information as well. Setting up an isolator test stand might be something to consider.. set your quad on the bench and have a beat up prop and slowly ramp up the RPM and record BB… Try it hard mounted and then with the isolators… try to get enough data for a transmissibility curve… but just trying whatever isolator is available off of Amazon makes it tough. Should we be looking at the other end of the problem maybe? Engine isolation? Certainly the approach for cars and real airplanes…

@@REDhlg There is one way we could do this that could work out best. Two gyros. One hard mounted, one soft. Subtract anything that changes from the hard mount to the soft mount. Everything that's the same overall amplitude and movement is real movement that the FC needs to know about. Everything else is garbage.

In precision shooting competition, barrel harmonics is a big issue and there are several ways to deal with them. The simplest is using a heavy barrel (just like thicker drone arms), this only moves harmonics to a higher frequency, you still have to tune your handloads to match the barrel or use a barrel tuner (movable weight). Another way to bypass harmonics is to have the muzzle of the barrel be constrained, this usualy means clamping the tip of the barrel to the stock, in drone terms this is like having a large structure of thinner struts instead of thicker one peice arms. Now to realy remove harmonics, deaden the barrel, you have to convert the energy, there are a few ways to do this. The simplest is to remove direct load paths, this means barrels with dimples, outside threading and axial holes arround the barrel, in drone terms this would mean the arms would have holes and zigzag edges in so that the forces have to go around corners (aka stress risers). The other way is dissimilar materials, this is like an aluminium or carbon fibre barrel with a stainless steel core, since the materials have different stiffness, much energy is lost transfering the vibrations. This is why carbon fibre is inherently a good damper since it is a matrix of epoxy resin and carbon filament, this is also how cars remove body vibrations by bonding a layer of urethane to the metal pannels.

@@paint4pain of these options, the different materials could be the best one for us except that in our case, we don't see waves of vibrations as much as we do overall twisting or wiggling of components. Waves are approachable with different materials and we still get some of that but the main issue is the odd twists and wiggles. One of the main benefits of the H frame design which attracted me to it is that the frame will essentially have no pitch action vibration wise because there's nothing to wiggle. At least not with the energy given. Yaw won't be a big deal and is seldom a problem, roll is the only issue I need to resolve. The body twisting. That's the only notable mode that's gonna kill it. I have some tricks I'm gonna try....... we'll see

Absolutely 100% correct. This is also part of the reason why I need a damping system but just works sort of no matter what. If it is as simple as just strapping the flight controller to the top plate with all the weight on it, that would really be a miracle. Also, if you're able to lower your filters or just generally give the filters an easier time, they will be more capable in a wider range of applications. This would include wider temperature fluctuations. If we can turn off our filters, there would be no more tuning. Everything would just work right with a general tune because the system knows exactly what's going on with the craft

Sure, resonance. What about the rest of the vibrations?

@@Kabab yeah that too, i forgot to mention. You probably know him already. He's based here in the UK. Got his own frame range, and goes in pretty hard scientifically. And no I'm not biased as i don't own any of his frames. Just saying incase you haven't heard of him. 😉

@@k1ortia yes I know of Chris. His work is good however he tends to negate the real world often and believes he can simulate everything. He also seems to think he knows everything there is to know so it's pretty difficult to work with him. A problem which I too have had issues with in the past but life has kicked me in the butt enough to let go of all that. Maybe in time he'll come around too.

@@Kabab Funny you should say that, as iv often thought the same to. It's as iv everything is purely simulation based as apposed to real life testing. I'm glad you've put some new content out though as iv not seen anything for a while, so i shall be watching and continue to watch the future videos..😊

That would work great but you're also just adding gdead weight which is not great.

Right. Instead of a stator skew, the magnets are staggered

yeah that works except that you also bolt the thing together which negates anything put between the carbon. We need the actual material that's damping to also be durable enough to hold the craft together.

It's extremely fast drawing designs on SketchUp. I'll usually draw an idea and think about it over a few days while I adjust the design. I'll maybe go back and forth for 2-10 days until I feel like I have something worth testing. I work with four different manufacturers and I'll cycle through them with samples generally. Sometimes I'll use cncmadness.

The problem with moving the batt to the bottom is that the quad then flies different. This is how race quads mount their batt because they crash often and batt on top is destroyed in most crashes. Weight distribution is one of the most significant factors in a quads performance

Right. I've tried to hunt for that but haven't found a way to do it because the motors spin at the full range of rpm and cause the entire range of vibrations. Other things I've tried is four different shapes arms so there is no matching resonance. I ended up with four resonance peaks or just one really wide peak which was a lot worse. Definitely good thinking and I totally agree that the best and most efficient way would be to use some sort of interceptive material. That was my idea behind the steel cable. I'm hoping that I've stumbled onto something with mounting the FC on the top plate. Either because it's closer to the center of rotation, the amplitude of vibration is just significantly less or the frame is doing more damping because it's a longer travel path for the vibrations to reach the FC. I'm rooting for any of those to be true for all our sake.

Jello isn't the issue here. It's the vibrations getting to the gyro. What you do is dynamic balancing and the best way however it's very time consuming and doesn't last once you damage a blade a little or swap blades or even just unscrew and tighten a blade.

@@Kabab I tried today to change the flight controller to the top plate for the sake of interest. Without rubber dampers on the top plate but with dampers on the flight controller. According to the logs - it got a little worse. So apparently there is no difference in person closer or farther from the battery.

@@ekap123321 definitely good input. Thanks for testing.

Interesting

It helps on frames that need the help. It sometimes makes things worse on frames that don't need it. So it's consistently inconsistent 😑

It's just FEA software that needs to be configured to fit the model

I don't have a lot of experience with kiss but a direct hard mount is better sometimes. The rubber grommets have a lot of bound to them and can be excited by some vibrations leading to much worse vibrations. Not usually however since the FC is usually very low weight. The frequency is usually very high and not approached by most crafts.

About 5-6yrs ago, the best we has was the GoPro session 5. That cam still is excellent because of its size and weight. Back then, the 540-590g sweet spot for 5" with 2207 or 2306 motors was absolutely golden and the things we fly today with a giant GoPro flys anything like those quads. It's also important to note that less than about 540g wasn't quite as enjoyable to fly. Today, if we can just get below 700g consistently with a GoPro it would be great. Lots and lots of people will say that 50g or 100g doesn't matter but those usually came after the era of ~580g 5" quads with a GoPro. 50g matters. Not so much in an empty field but when you're dealing with low height parking lot ceilings and small spaces it matters.

@@Kabab Thanks for the reply. A change in weight of 10% isn't chump change, no matter what you're talking about. Take off 25% and its significant. The difference in flying my source one with a gopro vs. without (200g difference) is huge.

@@Kabab Sorry to bother you again. Could you help me with these two questions. 1) When you sandwich arms together, do you glue them, and if so with what glue? 2) In the brushless motors we use, is the bell pushed or pulled by the electro-magnets in the stator? Does it spin because of magnetic attraction or repulsion? I figured if anyone know this, it would be you. Thank you very much.

@@blueskyfpv If you want to use anything between plates of carbon or carbon sandwich, damping grease is the only reasonable option and you only need a very little bit. Otherwise I wouldn't recommend putting anything between carbon. Brushless motors pull magnets into place as the motor rotates. It actually doesn't push or pull, it just magnetizes and expects the bell to move into the lowest energy position as the magnetization rotates around the stator

That's a very very interesting idea but it would directly impact flight performance too. I actually do believe it would work however. I just never thought about it.

Whatever you use is the best thing. Floss is the best but a water flosser is absolutely fantastic if that's all you'll use regularly

That particular FC was super intesting. I wish we had more FC's with the gyro on a wire...a longer wire so we can mount the gyro elsewhere. The board itself would have a hard time really isolation anything because the gyro is so light it won't resist anything but very high frequency vibrations. Still was something

Unfortunately the GoPro stabilizer software which is just real steady doesn't work correctly with their new cameras. Gyro flow however works great and this footage has minor gyro flow applied to it. Mainly to rectify the fisheye view of the GoPro.

I haven't seen things taped or otherwise attached with an adhesive to the arm to be useful. They may improve durability but I wouldn't expect it to be any help with vibrations

It can actually hurt a lot. It's difficult to tell without testing it. Could help too. Definitely very hard to say it always helps. Especially if they're rubber with rebound. Also, they're definitely making the frame weaker. Gives them a stress point

😂

That's actually a really good way to go if you can get it to stay consistently. I do this often to test things to see if vibrations are an issue.

I think you're talking about new resonance from the mounts allowing for wobbles. That's the reason I made the stance as wide as I could but it still happened. I'm not sure what you're referring to regarding maneuverability

Hero 8 in the beginning, hero 11 in the second one