How vibration and damping relates to FPV drones and how to increase damping to improve performance!
Вставка
- Опубліковано 2 сер 2024
- In this video I take a deeper look at vibrations and damping as they relate to FPV quads. We see how vibrational energy is generated, stored in resonant modes, and eventually dissipated as heat.
Finally we look at several different methods of increasing damping and therefore reducing vibrational energy in our FPV drones.
ImpulseRC Apex Video: • ImpulseRC Apex Vibrati...
A demonstration of magnetic damping: • Copper's Surprising Re...
Where to buy the Grease:
UK:
767A: shop.newgatesimms.com/product...
PG-44A: shop.newgatesimms.com/product...
USA:
PG-44A: www.oveready.com/flashlight/n...
767A: www.oveready.com/flashlight/n...
767A: www.tai-lubricants.com/produc...
EU:
767A: www.micro-tools.de/en/Greases...
If you are struggling to find Nyogel this is an alternative (but not quite as good): www.aliexpress.com/w/wholesal...
Support me on Patreon: / chris_rosser
Timestamps:
0:00 Intro
0:26 Why are vibrations important?
2:34 Filtering adds delay
4:56 How increasing damping can help
6:00 Barrel of water analogy for vibrations
8:15 What is damping?
8:58 Types of damping
11:06 Vibration model for a standard frame
12:28 Adding tape between joints
13:39 Apex arm mount hypothesis
14:33 Adding damping grease!
15:41 Comparison of the different methods
17:50 Comparison of different greases
19:35 Outro
Finally, a REAL engineer confronting the mysticism and alchemy still plaguing FPV since the early days. Thank you, sir, for pulling us out of the Dark Ages. Your legion of followers is growing!
Welcome to team FPV science!
Nyogel is the real deal and don't go thinking you can substitute something else. It's also really useful for our radio gimbals: Apply a small amount to the gimbal tension slides and you can make cheap ones feel smooth and buttery. Dry, creaky squeaky gimbals are revived!
Just got done applying some Nyogel. Coming back to see what I need to look for. Just applying it alone, you can feel that it's going to make a difference.
I love your videos, very informative and concise ✌🏽
You deserve more popolarity on internet ,thank you for your work.
Thank you for all the time and effort that goes into the production of your videos. I’m a visual learner so the in depth and methodical breakdown of each component that makes up a concept, demonstrated through your excellent graphs and diagrams really helps me understand the material on a much finer technical level.
Also, the videos themselves are produced with no (as detectable by me) continuity errors or mis spoken terminology, which is hugely confidence inspiring when discussing applications as technical as these.
Thank you 🙏
Excellent video and content presented in a very clear and concise way. Well done 👍😀
Thank you kindly!
This is super interesting to watch!
Just tried to blackbox-filter my Tinyhawk Freestyle, which suffers from a ton of Gyro-Noise that always translated into self amplifying D-Term oscillations when I throttled up. Aventually I ran out of filter banks to use and while the result was a lot better those oscillations wheren't gone. So in a "screw it, what could possibly go wrong at this point"-kinda mood I used electrical tape to softmount the motors... and BAM - D-Term Oscillations where completely gone. Now it's time to reset these filters and do it all again - seeing how much less filtering I can now apply.
I didn't expect that a multi-part arm design is also better for dampening then the inherently stiffer single-sheet arm design of these tinyhawks, but once you think about it it makes total sense. You wan't these vibrations to not reach the center part where the stack and gyro are mounted - so everything that dicipates energy before that is favorable, as long as it leaves the movement-freuqencies untouched. I may try some foam tape on my arms to dicipate a bit more energy on my particular frame design which shouldn't add to much weight - great tip!
I just got a tube of PG-44a in and can't wait to try it out and see what difference it makes.
It's been 3 weeks. Give it to us straight. How'd it go?
@@Cappurnikus I'd say it's worth it. The stuff is super sticky and adds more time to your build but I feel it works. Even just spinning a prop by hand has a different sound. I just did a new build with a QAV_S JohnnyFPV edition and the raw noise is the cleanest I've ever seen in any of my builds.
thanks Chris..!
You bet!
EXcellent video, I bought nyogel, I will try in my Fpvcycle Glide frame!
I bought fpvcycle brand damping grease
@@divingfalconfpv4602 nice ! How is it working ? after 2 years I can say that I have not find a substantial gain at least with nylogel in the long range 7” builds I tried
After several tries, I understood my 10-inch frame suffered from resonance. At certain throttle levels, I could see the shaking effect (high-frequency vibrations like a shimmering effect) on the GoPro footage. No tuning could remove it. I could also feel the prolonged resonance if I tapped one of the arms hard and only held on to the top plate. Felt it on the GoPro mount as well. Tapped my other frames, 8 and 7 inch and the resonance was very much more short lived. Applied electric tape on the arms on both sides where they make contact with the frame. And boom, the frame ,as I would describe it, is dead. Like striking a concrete wall. No vibrations, no resonance.
Nice, Clear, into the point with comparison also with numbers! Thank U! As i prefer natural products n solutions i am gonna use real raw beeswax for lock n dumping as they did back in the days 😎
awesome. i'm following
Welcome aboard!
This is so interesting, I wish I still flew FPV so I could try it out. I had problems with really light race builds, but they are long since dead haha.
Bought the nyogel, thanks Chris!
Hope you enjoy it and it works for you!
Since you've got some experience, can you advise on the application on a frame, the amount for instance? My guess is a thin film will be enough?
Yep just a thin smear is all you need. If you put a little too much on it just squidges out when you tighten the screws so no problem.
I usually place a small I ring on each motor screw between the arm and motor that works pretty good in some cases
Kudos for saying that mechanical damping also adds delay. I think people have an impression that filtering with mechanical damping comes at no cost
It depends on what you are damping. Damping the FC will add delay, damping the arms and motors probably won't, at least in my mind, since those movements are not what you actually care about. IMO.
I agree. Damping within the frame doesn't really add meaningful delay while soft mounting the flight controller isolates it a bit from the quad and so does add delay.
What are your guys talking about? Of course damping within the frame will add delay. It's just that by damping at shorter distance to the source of vibration you push the frequency up and the level down (proportionally, so that the energy is conserved) and high-frequency noise is easier to deal with.
Control theory is very unintuitive sometime. The trick I use is to imagine the extremes, for example a soft-mounted motor. Think like mounted on a jelly. How would quad perform in this case. And by magic of LTI systems this thought experiment holds true for a real world system if it's not too non-linear.
Hmm, may have a use for the tube of Nyogel 767A I have lying around for other than lubricating gimbals on joysticks....cool. Nice work Chris
Go for it! If you've already got the grease there's nothing to lose, you can always wipe it off after all.
@@ChrisRosser exactly my thinking, will have to capture before and after logs and compare on my glide frame. 767A is designed for dampening so would be an intresting test.
Chris, thanks a lot for your videos. It is really interesting to watch them. You explain very clearly and intelligibly.
It would be great to see how do you apply damping grease in a video. I also have some questions. What is the weight of grease do you recommend to apply? How quickly does the grease become dry? What happens after drying? Does it lose its anti-vibration properties? Are there other "dry" damping materials besides electric tape? Can something like "Boom Mat Spray-on Sound Deadening" be used for damping purpose?
Hi, I apply the grease between the arms and main plates and between the motors and the arms. It will never dry. Dry damping materials do exist but they seem hit and miss wheras the grease is always beneficial.
"Recently increased demand has depleted our stock. Expect restock by July, click email me below to be notified when available." -oveready
You did this. Joystick gimbals and telescopes are now running dry thanks to you.
Chris I'm more and more amazed by your intellect and videos (first saw you in Joshua's videos), I wish to visit your lectures in university sometime in future when you retire! :) No, I really mean that is purely astonishing. Getting back to viscosity - here in Russia apparently we measure viscosity in so called Engler degrees (found it out just now, was lazy during primary school if I remember correctly) now MDS sheets for Nyogel products states that PG44a viscosity for example is 192000 cSt - which is 25344 Engler degrees (again I haven't found who else uses such measures except Russia) BUT our local shops have locally made damping grease available only with 60000 Engler degrees viscosity - so I wonder if that's even better will damp vibrations ( same other characteristics, thermals - frost\heat, etc)
Yes it should be really good. It's also important what temperature the viscocity was measured at. PG44a is much thicker at lower temperatures!
Yet another quality deep-dive into the esoterica of the FPV quadcopter. I'm flying a one-piece, 100mm, X-framed, 2S micro with 1.9" props in a 20' x 20' space [that's 6.1m x 6.1m in real units]. I fly in Angle mode, and thanks to your advice [as well as Mark Spatz & Joshua Bardwell] I've turned a so-so flyer into something special, in my opinion. I have no black box, so I have to rely on motor sound; stick feel and response; and the feel of the power train temps to tell what's what regarding my Betaflight tune. It sounds very smooth; it has almost no lag, it's very snappy with no overshoots, handles buffeting, bumping into things, and propwash really well; the battery, power cord, and motors are barely warm after 3 minutes of cruising - I can pick it up by a motor upon landing. My filter settings are even more aggressive: my D Term Lowpass 1 Cutoff Frequency is down to 40, only 1 for my Gyro RPM Filter Harmonics Number, 80 for my Dynamic Notch Min Hz, and 650 for my Dynamic Notch Max Hz. I've sandwiched electric tape into my motor mount, which really helped.
Glad to hear your quad is flying great! For filters higher cutoff numbers are more agressive so 100Hz is more aggressive than 40Hz.
@@ChrisRosser I see. Whatever the setting, it flies the way I like it now.
Would love to see a video on ways to damping a frame with electrical tape as it is easily available and easy to work with, also how close it gets to this grease. Great video btw!
Kabab did a video where he looked at using electrical tape. It's not something I want to recommend to everyone because its very dependent on the frame geometry and screw tightness etc. It can make things worse as well! Grease is a little more messy but much more likely to give a solid improvement.
ua-cam.com/video/Ybx4oVB2Vvg/v-deo.html - Johhny FPV was ibto this years ago. :-)
Mine definitely dampened the noise. Only thing I noticed is the max frequency is higher on my dampened log vs undampened, but I have a feeling that's because I didn't do a proper A/B flight for comparison. Either way, I feel more comfortable tuning now because of it!
Thanks.
You're welcome!
Excellent video again! I just got two questions about it:
- How good would a layer of printed TPU (0.2mm) on top and bottom of the arms would be?
- When will you post some flight footage so we get to know you as a pilot?
It's definitely worth trying. I've been chatting with someone on Discord who has very quiet logs and they have TPU and heat shrink on the arms as wire protection.
This is very interesting. I have made 'damping pads' before of various hardness using acetate silicone. I used to spread some silicone between 2 hard sheets using roller pin and side rails to get precise thickness. To control hardness, I mixed silicone with various amounts of mineral spirits. That way you can get it so soft, almost gel like, but still firm enough to get nice resistance to tearing. Perhaps that could be clean and controllable replacement to grease.
Very interesting. If you have time it would be very interesting to see the effect of adding this to your quads!
@@ChrisRosser Yea, you kinda inspired me to enter a rabbit hole called designing my own frame. Since I'm quite proficient in 3d modeling and have the equipment and experience in mold making / wet carbon layup, I figured I'll give it a go. I always wanted to try making something different than classic "flat sheet cutout" frame, something with some curvature to it to give it more rigidity, and to avoid the use of standoffs. It is not a commercially viable project, since you can't just throw a sheet of carbon on a CNC machine, but it is something I wanted to do for a long time.
I just got a hang of modal analysis stuff in Ansys and am excitingly running sims on my designs, figuring out manufacturing part along the way.
Just wanted to thank you for your time you are putting into your videos, they are really inspiring and informative. Thanks!
If at all possible try silicone thermal pads probably of 0.5mm variety or may be even carbon thermal pads. I imagine they might do a better job than tape with quite a bit less mess all round. At least it should be interesting to test IMO.
All this makes perfect sense now, but it has me thinking there might be something to that old trend of soft-mounting our motors to tackle the vibration at its source. Thoughts?
Also bought some for testing. Currently I'm a bit unsure, where to put it all, but will find out. For now I'd put some to all screws and a tiny bit to the contact surfaces of the carbon pieces. Don't want to mess around too much.
FWIW he has a UA-cam short video where he discusses where it should be applied.
As a noob pilot I am curious to see if there is a real difference at how the quad can fly when noise is less.
I would appreciate a flight example of "before and after " video.
Congratulations for the scientific type of explanation of your videos, there are not many (if any) like this
great video,, make me want to figure out how to tune a quad. love how you really break down issues in a simpler way. thank you
could u point me in the direction to trying to figure out what a notch filter, low pass filter, and all the other filters, and how and why and when to use them ? I've been to uav tech page, he just talks way to much and fast, I'm trying to learn the basics first
Lots of people have asked me to do a tuning video. I'll give it a go when the weather here improves.
@@ChrisRosser thank you, I'll be waiting for this one. any recommendations to another youtuber to look into while we wait, for tuning and blackbox ?
How often do you have to reapply the grease? Does it ware out? Do its effects diminish over time? If its effects diminish you will need to gradually change your filter setup I would think. Great videos!!! I am an engineer and your approach gives me a much better understanding of what is going on with my quad!
The grease isn't going anywhere. It'll certainly outlast the life of your frame.
Another means to dampen theoretically would be to use an extension such as landing gear cylinder made out of TPU to be mounted below frame mount of the motors. This function acts akin to an archery stabilizer and the resonant energy is dissipated below the motor. Geometry of solid vs hollow or with gyroid internal supports should provide a means to do so, but at a cost to weight, but would provide benefit of landing protection.
A tuned damper is a tricky one. You would need to tune it to a resonant frequency of the frame which will be slightly different for every frame.
Great content Chris. Recently greased up my PFVCycle Prototype. The results were good, but man its kinda messy lol.
I'm just getting my prototype ready today and used electrical tape, I'm not going to have a before and after but I've seen someone else before and after in the frame and it helped, would love to hear your results
@@ugpfpv361 not sure I can post a link, but go to my channel and look for a video called "KababFPV told me to tape my quad" that has the results and the logs in the description. I also have a recent video called "Chris Rosser suggested greasing your drone" that also has logs in the description. basically going from nothing -> tape was a MASSIVE improvement. going from tape -> grease was a small improvement further, but was messy.
Thanks for testing Mouse. It's definitely messy but I'm glad that you saw a further improvement because that aligns with my testing as well. I found the grease washes/wipes off with a bit of warm water and soap.
@@ChrisRosser yeah, if I was working with a naked frame I would have used some Dawn and warm water, but left all my electronics on the main deck and was sort of trying to work around that haha. Sometimes trying to do something the easy way turns out harder, I probably should have done a full teardown a rebuild in hindsight.
👍👍👍
So soft-mounting motors is actually a valid technique? Thanks for a great video!
something that I think works for me is to leave the motor wires long and wrap them around the arms and then wrap them tightly with electrical tape. Maybe wrapping them with TPU or NinjaFlex or something a bit 'heavier' or rubbery could do better. I have a 5" marmotte and a 4" gecko with this 'damping' method. I love unibody frames
I'll definitely have to try that wire wrapping method. It could be a very easy way to add damping!
@@ChrisRosser if you try it, let me know if it's really making any differnce :). I need to get into blackbox reading so I can see it myself.
Watching this while assembling my unibody frame...
It would be interesting experiment to use Piezoelectric transducers as an intermediary between frame and arm etc to generate a means to harvest energy instead of heat. Imagine a joule thief circuit being fed by the piezo elements to power a LED system or feedback into a power system with adequate diodes as valve.
Haha I was just thinking about active cancelling with piezo, could be combine the 2 for best of both from same mechanism. A supercapacitor would give you your intermediary storage.
@@DigitalArtisan77 Agreed. A very small super cap would keep the LED's running a long long long time!
@@diveflyfish well it would, but also everything could feed it including regenerative breaking etc if the supercap buffered the main batts. Lots of little savings of power.
@@DigitalArtisan77 Not sure about regenerative braking but any use of joules vs heat is a step in the correct direction. Rather, the electric energy captured could shunted to keep the board alive etc. Low current draw aspects powered during flight would allow for longer flight? Probably nominal, but it would make for an interesting gizmo modification.
@@diveflyfish regenerative breaking is already a thing on some commercial drones. A motor is also a generator after all and theres nothing the consumer market can build that we cant. The future seems to be moving to many small gains rather than big inefficient ones I feel.
We just need a little "speaker" to play the opposing resonance into the frame. Like noise canceling headphones. I'm guessing little would be an understatement.
You're completely right and good thinking, active cancelling totally a thing and wouldnt need power.
wrong.
Little speaker and 100hz tones = will never happen.
@@TAGE_FPV it depends if you understand what he's saying and that's to impart a cancelling resonance with a magnetically driven mechanical device capable of such. Sorry is 100hz a valid measurement or missing some zeros? That's not a high frequency.
@Justin Hunnicutt why are you attempting to school me in what I told the other guy? The 1st guy had a great idea but not the terms to express it, the intellect good but the language lacking, that's still a win in my book, some ball bag can't grasp the greater concept and issued his response disrespectfully IMO., As I said "it depends if you understand what he was saying and that was a mechanically actuated frequency generator to counter those generated in the quad..., but all that aside, if that's the frequencies that are causing an issue, in the context of vibration and resonance it's a ridiculously long wavelength, like the length of the quad or arms need to generate that, have you heard a 100hz test tone? 🤣 a cat purrs at 100hz, that's definitely requiring mechanical damping.
Hey Chris I love your videos !!!!
Would you be willing to share your tune for the GepRC Mark 4. I saw your filters and would love to try your tune. I converted my mark 4 to the vista nebula pro.
If you have a tune for the HD version I’d love to see your tune.
I dig this one I have slight flickers in my goggles
👍Another good one. Would RC cars silicone oils for shock absorbers and diffs be suitable? They are sooooooo sticky... If yes, better to use higher cps number or lower? Thanks in advance for the answer. 😉😁
Possibly, I would try the highest viscosity available. Worth comparing its viscosity to PG44A to get an idea if it's worth trying.
Chris, what in your estimation would having a FC immersed in a dielectric fluid do to the signal to noise ratio and if one were to do so, what aspect of the PID would be best altered to filter more if necessary? Assume two distinct density alterations one 1.8X as dense as water which is 800 times more dense than air and one .75 as dense as water. If you have a means to model this please let me know. Also, let me know if you do test the material I sent you a link to from 3M on the Viscoelastic film. Thanks and great work again.
That's a very interesting question. Is the FC floating in dielectric fluid or is it still screwed down with standoffs? If its screwed down with standoffs then I don't think the fluid would make much difference unless it was so incredibly viscous that it could damp the tiny movements of the FC board.
18:00 the nyogel spectrum has a much lower peak at the ~100Hz 'propwash' frequency.. i'd have thought that up to a point there'd be more damping at higher frequencies than lower? or is the amplitude of the displacement across the grease that much greater from prop wash? (or is it just really hard to be consistent?😅)
Would the displacement or heating effects be big enough to be seen under a strobe/slowmo or FLIR respectively, on a bench test?
Tried to look for Nyogel in Mexico but little luck. What alternative can you recommend? Great vids!!
There are alternatives in the description such as XY2. 👍
Been looking forward to this...... I reckon a few like Mr Bardwell are slightly skeptical of whether the advantages are worth the effort.....
Bit like soft mounting motors years back
I'm just doing an Apex build, going to do a "feel" test before and after adding the grease without looking at blackbox etc at all.
Im just an average guy with average skills.......Will I "feel" a difference?????
Skepticism is great for science! Anyone who is unsure can test this for themselves and report back to the community their results. With more data we will be able to be more confident about whether this damping grease is the right answer. 😁
@@ChrisRosser Just finished watching the video In full.
And my concluding thoughts are (but will continue to think it over) this is definitely something worth doing even if we can't easily "feel" the benefits as it clearly will aid the FC to do its job more effectively!
Thank you very much for this information and the time you have put into it.
The only negative now I see is the cost of the grease..... ouch!
id doubt you'd feel a difference on the apex, that frame is solid enough as is
I would think that doing a before and after would not reveal anything. The reason to add damping is to be able to lower the filters without having resonance issues.
If you tune the quads filters to it's limits before the grease then see if you can reduce them any more after the grease. Just adding grease alone isn't going to make it fly better unless you already have vibration issues at your current filter settings.
@@CricketyChris Yes I agree completely
So like soft mounting motors of old many may question is it really worth doing
Thanks always! But i’d like to know how to apply the grease just put on the surface of the arm and plate? I’m waiting for
Aos 5.5 😁
You just put it between the arm and the plates. There is no secret to it. Just a thin layer!
@@ChrisRosser Isnt the grease squished out when tightening the screws?
nice info 👍 how about tapes? electrical tape or kapton
I'd use electrical tape. Kapton isn't thick and rubbery like electrical tape.
Can adding silicon between the plates and arms of the quad have some damping effect? might be interesting to test different methods
It is definitely worth testing. I think, based on my understanding, that it might not work as well as grease but this stuff is hard to predict!
i had a source one v3 build that would have hot bolts on the arms after flying. It was just the ones that went through the arm. Sometimes they would almost burn you. Is that from vibes? I have since moved on from that frame but just curious what caused it. Never had that happen before on any other quad
I ordered this fpr my 5" long range but didnt ever put it in. About to use it on my 8" and 10"
How do you think a 3d printed TPU fine piece (like 1 or 2 layers around 0.4mm total) would behave? The one we use for example is 98A shore, how would that stiffness/damping compare to the electrical tape?
The only way to be sure is to try it. In general I have found electrical tape and other materials to make some builds better and others much worse. It's very hit and miss. Damping grease (PG44A) is beneficial for all frames. No-one has reported it ever making things worse. So I recommend that.
This shits over my head but I like it . 👍🏼
You probably know more about this now than 99% of pilots! Welcome aboard the FPV Science Train. Next stop knowledge.
This may be from way out in left field, but what do you think about adding a brace from side to side or front across the frame, that would end with a slant up to the motor arm, attach to the frame at 2 points, and one attachment point to the arm with the grease added between the brace, frame, and motor arms?
One other definitely off the wall idea is what do you think a thin coating of plasti-dip spray would do? It is a rubber coating that you can buy in a spray can.
Just curious what your thoughts about either of those would be.
Thanks!
That sounds like it would definitely help. Plastidip is an interesting idea. Worth a go and doing a blackox before and after to see the effect!
@@ChrisRosser I just happen to have a can of it here that I can experiment with lol. I might have to go ahead and order a new frame first to try it out on. The only 2 I have here are unibody frames, and I don't know that it would have the same affect on that kind of frame.
anyone tryes the silicone engine gasket. like RTV or other, i think it should help to
Do you think that applying the grease between the motor and the frame would be useful?
I apply grease under the motors and under the heads of the motor screws, I have found it helps quite a bit.
The viscosity of PG-44A is almost 7 times that of 767A at 40°C and 5 times at 100°C. Do you think they are still comparable in use? I did do a quick test with 767A and it does seem to have some effect, just wondering whether a more viscous one would work better.
I would say that PG44a is probably the best. I've found it work really well. 767a is cheaper though and more available.
Can anything be done for a single plate frame like an Armattan Chameleon? Are there effects of having single esc's on the arms? Wondering if the added weight and mass on the arms make a difference.
Single plate frames are harder. There are constrained layer damping tapes available that you can try.
I can't buy PG44A in China, but should I choose high viscosity, low viscosity, or medium viscosity for other brands of damping grease?
I wonder if carbon fiber could be made with a damping material between the layers?
There is one. Furribee X215. I have 2 of them, they were both bnfs. Frame might be ok, maybe also because of that, but those quads had so many other faulty components which made them so problematic.
@Grim FPV Can you tell us more? Maybe even make a video?
No because the damping material is viscous and does not set.. The epoxy resin that is used in carbon fiber is fairly ductile and when paired with carbon fiber (the stiffener in the composite structure) you get the combined performance of both. If you were to try to use damping grease it would be the equivalent of trying to build a kwad out of old honey and table cloth.
@Grim FPV Foam layers are cool unless you have a don't have any out of plane structures in your frame design. If you don't you will get the same issue that the TBS Source Aureo had which is the foam splitting and then you are left with 2 halves of foam and carbon - foam is not great counteracting interlaminar tension... and the foam splits.
@Grim FPV I do some development for NBD and I would be happy to setup a video chat with you to talk about how I would go about doing it and some of the advantages and disadvantages of it from a composites standpoint.
So... I need to install a barrel on my quads?
Curious, v. Curious. I think we need analysis of multiple tests on multiple frames. Perhapse request submission of bbl for analysis?
I've retro fitted a single layer of tape on the glide but not sure there is a significant difference
Still the new best source for new info pushing quads atm
We definitely need more people to test on more frames. It will take time to build confidence but initial results look promising!
This jives with your apex unicorn theory. I also still use tpu motor mounts even if only 0.5mm dont care what anyone says lol. (Edit - just got to the apex reference in the video when i posted this lol)
TPU motor mounts will definitely absorb some vibration, don't let anyone stop you!
@@ChrisRosser this also myth busted my theory that unibody frames are less noisy. But I can see how for say 4 inch lightwight long range (no acro) builds the cost in loss of dampening is outweighed by the weight savings particulalrly with smaller motors often at steady throttles making much lower noise ... I think?? Lol
I have an Armattan Chameleon 6" frame that is notorious for being a bad vibrator due to the large unibody bottom plate. Many good things about the frame, but it's noisy.
Does the dampening grease really add a large resistance dampening component to shear? I understand viscous coupling example of the dynaflow transmission in old autos. The efficacy of the use of the shear, is proportional to the speed and proximity and as one increased the flow and closer the proximity the more the coupling occurs. Is not more than viscous needed? IE viscoelastic to store then dissipate energy? . Is it possible that the hypothesis of resistance to shear in your example is actually primarily a dissipation of frictional imparting of vibration akin to a bow of a violin? I would argue if one placed dampening grease on a bow of a violin, one would probable see a very atypical noise emanate from the violin....... and the bow action would not be more difficult, rather easier to do primarily due to reduction in shear force, but the sound would be less due to frictional vibratory decrease? Perhaps I am wrong, but the concept of a grease for the functional increase of resistance to shear is rather counterintuitive. Again awesome videos and thank you for your instruction and level of detail to understand this nuance of topic.
I pose the above as a questions and not from definitive answers to be sure. So please excuse the questions. The reason I ask is that if one has a greater degree of coupling in shear due to the grease, would that simply shift the energy to a different harmonic? Does your system calculate energy below the curves as dissipated energy lost from grease to no grease? Thanks again for any clarification. I do see that the grease does work in shear to be sure. I am just wondering what aspect really is being dissipated. What one would see if a identical frame were glued using a RTV silicone vs the Viscoelastic material would be of interest as well. Really awesome work.
The damping grease allows the surfaces to move slightly relative to each other. It also creates an enormous amount of energy dissipation due to the viscous forces inside the grease because it's viscosity is so high.
There is some plastic frame or even 3d printed frame. I will belive that plastic act like a damper. What do you think about plastic design? Are they good to reduce vibration to the gyro?
I think plastic might not be stiff enough for anything except the very smallest whoop frames. Stiffness is vital for resonance performance.
Hm, guess I am unlucky...
I have 2 vertical frames and an Armattan Marmotte, guess no improvements for me this time 😅😅
just some stupid question: can i use thermal grease???
I don't think so. Mechanical damping grease is much more viscous in my experience.
@@ChrisRosser out of curiosity and because i cant find any store near me here in indonesia that sell damping grease, i just tried using hy510 thermal paste between arms and plates, combine it using electrical tape on standoff-plate-screwhead on my heavily high throttle oscillations cheap local frame. The result is amazing, i don't know how to read gyro plot but visible vibration on camera when i punch, it's just gone.. thank you Sir..
👍👀🇭🇷
So JohnnyFPV's soft mouting with electrical tape wasn't total BS?
I'll try with beewax instead 🤔🐝
Good idea, let me know how well it works.
why don't we focus on a solution for the FC itself. Will be compatible with more frame.
Damping grease is compatible with most frames. I challenge you to find a frame that I can't smear with grease! 🤣
why don't they use DSP instead of just filtering?
If by DSP you are referring to digital signal processing then I think Betaflight's filtering approach with multiple dynamic notches and low pass filters would qualify as quite advanced DSP in my opinion. 👍
@@ChrisRosser then how come it can't filter out noise from things like an antenna vibrating?
methinks the DSP coders have some more work to do.
@@embededfabrication4482 The main issue is that antenna vibrations occur at similar frequencies to fast flight movements like propwash. You want the quad to be sensitive to those frequencies for good propwash performance. Unfortunately that also makes it sensitive to any vibrations at those frequencies (including antenna vibrations).
Hi Chris, yesterday I saw in TV a startup, which makes a new stiff and light compund material. Because of the nature, it has a high dampeing factor already buildin. Unfortanetly I can´t find a english webpage, but with google translate... : hardcork.de/use/ hardcork-skateboards.com/ It is a compound of cork, fiber and resin. They advertise it as replacement for carbon fiber, but because of cork it should have a much better buildin dampening compared to carbon fiber. Is this a new material for frames on the future???
It's possible but I struggle to believe that it could be anywhere near as stiff and strong as Carbon Fibre. The applications are surfboards and skateboards. Plywood for skateboards has a stiffness of about 7GPa compared to more than 70GPa for CF. Based on that gut check I think it'll be too floppy. Its a cool material though, thanks for making me aware of it.
Anyone who has dealt with honey oil (used on wireline grease injectors) can tell you how stick, nasty and how much of a pain in the butt this type of grease is to handle and clean up. WD40 and Marvel Mystery Oil is about the only thing that can cut it.
PG44A, 767A and 774VH all clean up with dish soap and water and don't stain. Trust me, I've got plenty of it on my hands and workbench!
Ok that's the most stickiest stuff on planet earth. What a pain to clean it. Got it me. On other parts of the frame
why did I get this in my recommendation
Are you interested in drones and FPV? Did you enjoy the video, so many questions!