I'm an Aerospace engineer and I just discovered your channel as I was doing research to pick up my first hobby-grade multi-rotor. You've definitely got some good stuff and I think you are spot on with this video. Multi-rotors rely on their FCs to stay in the air and the better the data going into them, the better the FCs can manage the overall performance of the vehicle. There is a downside to soft-mounting, though. The soft-mount trick works because it allows the motors and the props to "wiggle around" on their mounting pad, so the mounting material actually absorbs/damps out a lot of the high frequency vibrations originating on the rotor side of the interface, such as vibrations from an iffy bearing. The problem is that this also allows the rotor head to slightly change angles based on the vibrations being generated by the system and the larger torques being created by the motion of the aircraft. These motions should be pretty small, but even a few fractions of a degree could be enough to cause the control logic to have to take action to actively try to suppress this motion in the control loop. Will you feel any of this action? Probably not. However, it could result in a slight "softening" of some of the control inputs by introducing a slight "lag" in the control channel. Imaging the nice rigid rotor arms are flapping around slightly under load, so it takes a fraction of a second for the system to settle down and return to a steady state when it is upset or you introduce a new control input. Again, this will probably be way below the threshold of what most folks would notice, especially for a vehicle in this class, but it is a real byproduct of having anything "soft" in a system that expects everything to be rigid. Again, great video! As a noob to this corner of RC, I have learned a lot from you so far.
I learned this years ago when I soft mounted my wife's thunder stick 2000 to the headboard! I have slept like a baby since lol good stuff man thanks for sharing this information with us 👍🏽👍🏽
I enjoy listening to you Joshua because you keep talking without stutter,coughing,excuses of any kind and distracting from the subject.You have a knack of keeping to the point and my attention.Good job sir.As far as the vibrations are concerned I’d say insulating the arm to the frame ,if possible would be less tedious and also the motors can still keep their ridged mounting without the wobbling.
Don't let theory ruin a good experiment! AWESOME! I get excited when my hypothesis is wrong! Most people try to force their hypothesis into the result. Not good science folks. Your killing it as always Brother! Keep it up.
Finally a video with some objective data and proofs. Thanks Joshua. Instead of electrical tape I'm planning in using silicone backing sheets, 1mm thickness. Softer, cheap, doesen't leave a sticky mess and is high-temperature resistent. Also, I think is better using only 2 screws for motor (A' la FGA or MrSteele), it will give more wiggle room. Edit: [On a side note: If you find the perfect silicone backing sheets already in your kitchen, better ignore them and order some new one from Amazon. Your significant other may disapprove.]
Thanks much again for your (very valuable) time Joshua. Just at the first motor here. The tape I had sitting around here in OZ is Scotch Outdoor. Cut mine at about 60mm before folding to create a couple of small outer corner 'bumpers'.
Thanks Joshua. I was anxiously waiting for your test, but was thinking "Joshua wouldn't touch this topic with a ten foot pole, would he?". Anyway, great results! A couple of us did post similar controlled tests on Facebook, which confirm your observations. Most who payed any attention to it were convinced instantly, but the vast majority were laughing too hard to notice.
Thanks Joshua. I'll try this tonight. My quad flew away yesterday but lucky it went directly straight up to the sky since I was hovering. My setup is Emax Eco 2306 2400kv, Spedix GS45 4in1, Hyperlite F4 OSD v2 flight controller and 6" props. I could not believe what I saw and heard in the span of 2 seconds. I was hovering the quad and it was about 10ft away from me when suddenly, it flew to 150ft high and I was so friggin scared since I'm a newbie to this. I wasn't aware that flight controllers should be soft mounted. I was told yesterday in one of the Discord channels. I'll fix it later. I'll try soft mounting the motors too, Thank you Joshua!
Hello Josh! Saw this right now here in 2018 and i do have some technical knowhow in filterdesign to share that might help understand why there are still noises in the Gyro Signal (also an idea on how to reduce vibrations even further). Filters in genereal: There are basically two kinds of filters, HIGH PASS Filters which cut out only low frequencies from a signal, and LOW PASS Filters which cut out only high frequencies. You can also combine those two Types (but that doesn't matter here). As you can imagine, what is used in the gyro-application is a LOW PASS filter, as we want to reduce high frequencie noises that mess around with our gyro-feed. The reason why you still have noise after the filters are applied: However, the term "CUT OUT a frequencie" doesn't really apply to what a filter is able to do. Filters, no matter if analogue or digital (what is used in every gyro application for quads) can only dampen a noise down to a level where it doesnt matter anymore, and they do it gradually from a fixed frequencie on. (See: upload.wikimedia.org/wikipedia/commons/thumb/6/60/Butterworth_response.svg/350px-Butterworth_response.svg.png After the fixed Filter Frequencie (cutoff frequencie in the graph), the damping is not straigt, it is gradually) The gradual decrease of the noise intensity above this fixed frequencie is the real reason you can still see noise after the filter applied, because it is simply too close or even before the fixed frequencie. Other Way to reduce vibrations (not tested, since i never flew anwhere else than in the sim lol): To do that, you could also try to softmount the arms that hold the motors. This approach is not possible with every frame, since you would need the arms to be mounted individually, but it should work on the wizard.
I watched this video the same day it was posted but never soft mounted my motors out of laziness... I soft mounted them today and just WOW!! It really maid a difference. I had some problems with vibrations and I had soft mounted my FC but it wasn't enough and soft mounting the motors really got the problem fixed.
fpvYou interesting use of Corrosion-X. Do you need to re-apply bearing oil afterwards? (Like how a more refined oil will act as a solvent on a less refined oil -- I don't know how Corrosion-X compares to bearing oil like Scorpion.)
Mr. Bardwell, I've been experiencing crazy noise in my FPV goggles, especially when at high throttle punch outs. I've ripped my quad apart so many times in an attempt troubleshoot the issue but to no avail. I switched cameras rerouted wires and still nothing. I was beginning to believe that it was my PID settings. At the time I was using Cleanflight but recently switched to Betaflight. I finally got my quad to fly super buttery and locked in, but the damn FPV goggles still had a isht ton of noise. I finally soft mounted my motors and now my video feed is solid. Thank you. I also like to thank you for many of your other videos as well. So thanks again! I'm in Sherman Oaks and would love to rip with you one day. Best regards, -The First African American Quad Racer - QUADristotle
Excellent. Glad it made a difference for you. You can also add capacitors to your ESCs which will probably fix the noise, if you didn't do that already.
I do in fact have nasty vibrations in my Tarot 130. 2 motors came buttery smooth, 2 sound and feel like the bearings have rusted out! Will try this and report back. Thanks for taking the time to test this and report back to the community.
Ok now that I have watched the whole thing, that's really telling. I suspected that we would see results like this after thinking it through a bit. It's the same reason electricians put rubber grommets on big transformers when they hang them. It dampens the vibrations and keeps the "hum" down.
Willard, Johnny and Kevin all had vids about the same time on this - good flight videos after doing it but no empirical data. Again, thanks for performing the test and publishing Joshua, this is exactly why vlogging _ISN"T_ killing the hobby but instead educating and making everyone a better pilot.
Vlogging with information is fine. Just because a guy is on camera talking doesn't make it vlogging. I am personally bored by vlogging about vapid stuff, but to each their own.
@Joshua Bardwell: I´m working as a engineer in the semiconductor manufacturing industrie and know "a bit" of PID, gyros, dampening, dynamics of vibrations etc. Because to produce wafers you realy need a good understanding how to keep your PID controllers dealing with the slightest vibrations. What do you think why it´s possible to do lithography in some nanometers resolution to produce computer chips? :-) I´m realy glad you did that video. After all the haters and people knowhing nothing about this just laughing and shouting "hypetrain" you did a great job showing the results. You´re right with most of your assumptions and did a realy great video. There are some other reasons why the connection of the screwheads are not a so big deal, not only the surface area, but your conclusion is damn right. Of course soft mounting is reducing the vibrations that your PID controler has to deal with. And of course, some people will feel a bigger effect that others, this is not only because of the motors, but also about the frame design. There are even enough quads with so less vibrations, that the gyro filters will output a clean enough signal. The most important thing beside getting rid of the vibrations is, that you indeed (in some cases) can tune your PID´s much better, resulting in higher P and lower D and a better tuned quad. I´m personaly sick and tired of discussing with haters who do not even listen and trying to understand, just trolling around and making jokes of others. Just look at all the jokes and memes in the Facebook groups. :-( Nice Job Joshua Bardwell, you have one subscriber more. Just one last hint: If you look at the spectrum of the vibrations without soft mounting, you may notice that the biggest amplitude varies in frequency between differend quads. If you would like to push the soft mounting further you could do that with selecting different hard soft mounting materials, because they will dampening better on specific frequencies. This can be achived with polyurethane elastomers in different shore hardness. There is no vodoo, this is just known engineering in some industries. :-) Keep on with your great videos!
This has transformed my quad video footage. Had some similar tape at home, used it on the wizard which had suffered vibrations after a crash and now the view through the runcam eagle is silky smooth. Thanks for the vid!
I beat the hell out of my quad, fly PC props and don't change them often, and I don't like swapping out motors once per month. I had great results from the electrical tape trick. However, after exposing my quad to moisture and mud and abuse, the tape started to peel and trap dirt underneath. Last night I applied 5 coats of liquid electrical tape to my mounts. I'm pretty happy with its adherence to the carbon fiber, and it even coated both sides of the screw holes. I'll be giving it a test fly today. Thanks for your comprehensive workup, Joshua!
Thanks Joshua! I have a friend who soft mounted his motors. His hd footage before showed blurry leaves on trees but afterward the leaves were crisp. Thanks for the black box backing to support his experience!
That's a benefit I don't see mentioned much in the discussions of soft mounting: less jello in HD camera footage. Thanks, Joshua, this is very compelling data. You are the Galileo to all the Aristotelian pundits out there.
Now the verdict has been finalized. I guess people will use torque hex key on specification material(e.g. silicon, tape, washer, etc) to fine tune the softmount. Sooner or later, there will be specify products for the softmount
Thanks for this vid. I like the fact that you take the time to show us these theories and whether they work or don't work, rather than random pilot on the internet saying "it works" or "it's b.s." Without any real evidence.
Mass vs. Vibrations; if the mass of the entire frame is isolated from the motors but hard mounted to the FC we have the mass working for us. Alternatively, when the entire frame of the quad is vibrating along with 99% of the mass and then we expect the mass of the soft mounted FC ( a few grams) to stabilize on a few o-rings we get very poor results. This makes me think of back in the day when David Windestal started making his Tricopter frames, the camera plate was suspended from the flight frame and included the mass of the battery. Now off to print some flexible motor mounts! Thanks for bringing this to light Joshua, not all of us have time to lurk in the forums or the tolerance to wade though people's BS! :-)
Great idea Joshua, people in general DO forget the physics behind many things in the RC world. Great advice, even if it's old news. Thank ya sir and...See you in the air. Wayne
Awesome video Josh. I like your comedic additions, namely your opening and homeopathic comments! Not to mention your clear explanation of why soft mounting isn't BS. Sadly I think most of the soft mounting haters on the rotor riot Facebook group are not the kind of people that enjoy your nuanced and scientific approach to these kinds of questions. Much easier to just make a meme than think critically
+1 on the soft mounting motors. Had a frame with yaw twitches I couldn't resolve. Soft mounted the motors with electrical tape after watching Johnny's video, and everything is right with the world again. Definite +1 on the need for loctite however. Only 3 packs through the quad and everything was coming apart.
To prevent the heads of the screws touching the arm, you can apply a spring between the head and the arm. By choosing the strength of the spring, you can also define the force of pressing the motor against the foam. Maybe a "Tellerfeder" (sorry, I don't know the English word) can also do a good job.
I asked you the other day about soft mounting motors . . . I got the rubber one's off amazon. . . . Currently not using them because I'm one of the people who aren't really having that problem. . . And they are a HUGE pain to get on correctly . . Then you run the risk of motors flopping off . . . And were talking about super glue . .. my quad flies fine . . Thanks for the advice !
Finally! Somebody did a proper video on this! Gonna have to give it a try on my quad as well now. Might not see any change right now, but as my motors wear out and get noisy, this should help keep it flying the same.
3m 4010 clear mounting tape works great. When a similar discussion went on in the rx helicopter world it was settled(mostly) that this is the best tape to mount gyros and flybarless units. I've been using it to soft mount my motors and it works well for me. Like the grey stuff it's a bit thicker than 4 layers of electrical tape but it compresses without loosing its ability to dampen vibrations. I am curious to see how the 3D printed mounts work since they would be much cleaner and easier.
Use a slightly longer screw and "soft mount" the screw side as well then you escape the contact of 1 axis of the screw. Bore out the holes in the frame and line it with mounting tape or plastidip, then it is fully isolated. Has anyone seen a spring setup? Having thoughts of the old car cd changers that still skipped. All this makes a difference but how much? Most of us are park flyers not aerial photography pros, so is it worth it for the hobbyist? FPV racer? Would be interested in seeing fpv with the data of each in a more controlled setting ie indoors with set parameters like a warehouse loop. Thank you for making great content, super informative. You Rock!
Perfect timing on this vid :) was going to soft mount tomorrow in together with an motor swap. with you confirming the possible benefits I got some new thoughts on how I'm going to do it. I run an tricopter with bracket mounts and the fc is fixed to all. RxExplorer mini. so you gave me thoughts of the end mounts of my boms :) Keep up the good work and help us thats new to this :)
I've been doing this for a long time, even before it was talked about like now, the benefits became clear very quickly. Now I can even buy pads specifically for this on eBay. Place them under the motors and with the motor protector under the arm the screws even tighten onto that, not the carbon. You can heard the motors sounding cleaner in the air, to me this is a must because of the benefits I achieve.
Great information. Time to cast some polybushes and drill out the mounting holes so even the screws don't touch! PU is available in a range of hardness grades. I build my micro quads from acetal because that's what I have available and I can cut it on my laser. Many people have been sceptical of acetal because it is not as stiff as carbon. However for a micro I think it is stiff enough. The fact that it is more flexible than carbon might mean less vibration is transmitted to the FC.
"It Done Got Better".LOL Great analysis as ALWAYS!!!! Thank you So Much for taking the time to actually show us some RAW Data!!!:) You are Sharp as a TAC My Friend!!! BTW. Thanks *Johnny FPV*, and *Willard FPV* ALSO!!!
Have a go at putting silicone washers under aluminium 'cone' washers on the bolt side of the arm to supplement what you've already done. I've done so in the past while playing around with reducing vibration for an APM board (with mixed success). It would be very interesting to see what data comes out a black box log with modern hardware.
I read somewhere before, yes 2 years ago, I think 3 years ago either about soft mounting these motors. This was when we still fly these 450mm hex, octo, all those bunch of big multirotor.
Technically you could even soft mount the screws. Apply the dampening tape also on the bottom side and fabricate a round plate with four holes for the screws to fit over it. The only surface that the screws could touch the arms now is with the thread itself. But you could easily eliminate that with drilling a bit bigger holes in the arms....
LoL at the beginning. I have similar shakes at around mid throttle, but the gyro traces are really clean. Haven't been able to tune it out and have been at it for months. It was buttery smooth with my earlier setup 20A little bees and 2204 Cobras. After switching to Xrotor 20A micros and Emax RS 2205 the shakes started.
Thanks for taking the time to do this experiment and post your results. I think I may give the soft mount a try with the same tape and see if I can tell a difference. I'm running the TBS Powercube on my builds and for the most part they fly smooth, but curious to see if this makes things even better.
awesome. I was too lazy to do this myself. I just tested a 1.5mm TPU pad on my motors but I need to get longer screws to feel comfortable. So ideally, the motor screw holes should be outside the base of the motor because then you can use a lock nut and then you don't need to cinch them down so hard.
Totally makes sense to grab the problem by it's root. Since the motors are the cause of vibration. If I had a bucket of water with a hole in it I would also concentrate on fixing the hole instead of topping of water to keep it full.
Engineer tip: Soft mount screw head as well, of same thickness and same material ideally :) Oring or 3d printed, you will have to find the right thickness, try slim and increase little by little :) i'm currently working on TPU shell print filled with soft silicone, but O-ring 1mm diam worked best so far.
Soft mounting helps in isolating vibrations. Best example is how am engine is mounted to a car ( with a soft rubber bush). I am a mechanical engineer myself. To those people who say heads are still touching, just squeeze the motor towards the frame, you can see the head coming out a little bit. That play (the mounting tape) absorbs a lot of vibrations. It's physically proved. It's not just imagination of bling belief..
Very nice. Thanks for speaking on this. I soft-mounted mine and thought I could notice a difference, but also wasn't sure if it was just in my head. haha ... thanks again!
This reminds me of the historical break-through in development of supersonic flight, where the first aircrafts were vibrating to the point of destruction. Until somebody figured out the trick that individual parts should not be coupled tightly: the tighter the coupling, the larger the amplitude at some resonant frequency specific to the aircraft as a whole (instead of small amplitudes of many frequencies distributed among many parts if they are not tightly coupled together).
Depending on the density of your pad layer, there will be different torques that will take advantage of the padding used. Basically you want it firm but not tight tight..
Soft mounting motors is a way better idea than soft mounting the FC. There is no mass in the FC so it will still jiggle with the rest of the copter, but if you hard mount the FC and soft mount the motors, the FC is attached to a large mass and large masses don't want to move because physics. Hope this makes sense.
I printed my own and it 100% worked for me . Had yaw twitching on my Connex quad, put them on, boom no twitching at all. I don't care if trolls joke about it, I now have it on all my quads and I am happy :) P.s. I was dubious too.... as you say screw heads still touching WTF? Well it works so I dont care!
Your videos are amazing! Thank you for being so scientific in your processes. Too many multirotor channels lean hard on their opinions vs objective results. Subscribed!
My quad flys so much better since i softmounted! really happy with the difference! You are a master of tuning josh! I would kill to get a glimpse of your final PID's for the wizard Mine came with 2 really bad motors as well :(
I spent a great deal of time on this issue in respect of tail rotor gyros for model helicopters back in the 1990s and I'm convinced that isolating the motors from the frame is a better solution than trying to rely on soft mounting of the FC on its own. My reason for saying this has several factors. Firstly, the range of frequencies of vibration in the airframe with the motors hard mounted is wide - the beat frequencies can obviously be anything from zero upwards. When it comes to soft mounting the FC you have two competing requirements - you want the FC's attitude to accurately track the attitude of the airframe that, in rapid roll, pitch and yaw accelerations (OK, we old heli guys will tell you quads don't really do decent yaw acceleration but I digress 8-)=) requires a low compliance to the mount while the need to isolate low frequency vibrations requires a high compliance to reduce the resonant frequency of the mount. By isolating the motors from the frame you are only needing to isolate the relatively high frequencies of each individual motor and not the much lower beat frequencies that exist in the frame with hard mounted motors. I think this easily explains why, despite the motor being quite firmly mounted, you are getting a significant reduction in the low-frequency components in the gyro traces. There is another effect which I think explains why you are seeing the relatively slow meanderings of the raw gyro traces (especially the yaw axis). This arises from the fact that, although the sensors are 3-axis, each element of the sensor is actually only a single axis device - sensitive only to rotation about the axis it is currently pointing. The effect of this is that simultaneous vibrations in pitch, roll and yaw can cause a single axis sensor to have a non-zero mean output when there is no net rotation about its nominal sensitive axis. To see how this comes about consider the following movement of the quad and consider what the yaw gyro actually sees. Tip quad 90 degrees nose down Roll quad 90 degrees right Tip the quad 90 degrees nose up (back to level) Yaw the quad 90 degrees left The quad is pointing in its original direction but the yaw axis gyro only saw the last of these motions and its mean output through this sequence is thus displaced to the left! The important thing is to realise this happens to a degree even when the angles of motion in the three axes are very small. So when you have the sensor experiencing simultaneous vibrations in all three axes its output will generally be displaced (the degree and direction depending on the amplitude and relative phases of the pitch, roll, and yaw vibrations and this accounts for the stochastic nature of the disturbances). The result is to get small amounts of drift in the yaw axis (reduced if there is a magnetometer to give another heading reference to add to the Kalman 'mix'). Twitches in pitch and roll are also to be expected as it takes time for the accelerometers to take gyro errors out via the Kalman filter. The final important point is that this vibrationally induced drift effect occurs even if the individual gyro sensors are “perfect” i.e even if they don't have any g-sensitivity or out-of-axis rotation sensitivities.
Quality!! 😁 Very much enjoyed watching. And a I am not only talking about the purely scientific part of "measuring". Received it as more entertaining than potentially initially intended by you. Very good!
i have bad quality bearings in my unbalanced crappy le todar 2204 motors, i tried soft mounting and it helped a lot. got more power too because the FC now knows what to do :)
Awesome video! Actually never heard of it, not that big in flying either so it doesn't matter much =D But I've learned something! Just a question though, could you perhaps take one layer of foamtape on the underside of the arm as well? Together with some washers or anything else needed so that you don't jack up the tape of course. Could that help even more perhaps? I'm certainly not saying that the screws are touching the frame, cause I think your results are really awesome! Actually I thought this was a "trolling" video at first, but apparently not =) But I mean, for those who think it does so much difference, could you try and make a video with one layer of foam tape on the underside of the arm as well? If you get what I mean ;) Anyhow, really awesome video! Never thought or heard of this before, but certainly.. Why not? It surely does some difference! You got yourself another subscriber also =)
Yeah I think you're right, it makes sense to have it on both sides. Because there is only dampening happening in one direction of the screw axis, and the other direction would be hitting on the frame. Perhaps either more dampening tape etc on the bottom side, or a spring washer with a decent K to 'pre-tension' the dampening. Late reply I know, but im about do do my first build.
Thanks for sharing. Very interesting. I started FPV back in 2012 when things like the QAV400 were the go to FPV quads, which back then was actually described as a small aerobatic frame, ha. Most of the popular frames around then had soft mounting built into the design. At the time I just figured they stopped including it in designs because software and filtering had improved and 250 miniquads didn't need it because of the smaller scale.....obviously not entirely true. I think maybe the Blackout 250 miniquad (now old too) moved the trend away from soft mounting and vibration dampening. When the Blackout 250 came out people were mostly using smaller 1800 sized motors on it. I guess now that motors have gradually moved back to larger sizes with bigger magnets and more torque; vibration issues are coming to attention again. Wonder if frames will start to move back to including vibration dampening into the design.
I think the long arms you see on some X quads adds to the vibration issue? Remember kiddies the arms don't actually have to converge to a single point to have 4 way equal motor spacing. It is just as valid to have arms mounted like the classic Blackout miniquad and have shorter stiffer arms. You could also argue the arms converging directly under the FC almost directly couples the vibes to the FC without any of the inherent damping the frame would have if the arms did not converge at the center. Basically I am saying converging arms are a backward step in frame design.
Excellent presentation. From the first time I saw the soft mount videos, it made sense. Will I do it? Probably not. I'm not that good a pilot and I don't race, yet. All my birds are low budget quads. So I don't really think any amount of insulation from vibration will make much difference. But for those that have spent tons of money on their gear, this should probably be something for them to try. There will always be naysayers. That's the way the internet rolls. :)
Interesting. Honestly, I don't do race and not an accro flyer. Most of my quad are big size and I mainly do aerial photography or just flying around for fun. The idea of soft mount should help reduce vibration from video too as it did to gyro. My smallest quad is a 260 running INAV.
Hi Joshua and everyone, has anyone thought of using the rubber self-vulcanising tape to soft mount. Its the stuff they use to wrap wiring harnesses etc and can be bought from most electronics stores and auto stores. The other question is, have you thought about putting one layer under the motors and one layer under the arms between the led plates? with a quad like the wizard you have the perfect plates under the arms to hold the bolts, maybe insulation on both sides will dampen all vibrations. Maybe the little silicone o'rings we use to soft mount the flight controller would work well on each bolt too. food for thought.
its funny you used that tape, as its what I have always used to softmount FCs as well as generally just stick down vtxs, escs etc. I finally encountered the 6500 gyro mid throttle oscillation too, FC was already softmounted but still had the issue, so I used this same tape to softmount my motors. it was a definite improvement, but unfortunately, not enough and I had to goto a new FC. left the motors soft mounted still. would actually like to see someone release softmount pads with pre cut holes, would make life easier
I printed up some soft mounts out of TPU - that worked really well for me. Just as an option as people explore - I dont like the tape option as it seems these will break down fairly quickly, TPU should last quite a bit longer. Thanks for the vid! :)
Screws touch bottom plate, but the motor doesn't, therefore the screws are able to move ever so slightly and reduce transmitted vibration.It's little stuff that make a huge difference, such as tiny little blobs of blue epoxy on motors to balance them.
It seems intuitive that soft mounting would have an impact on bearing life, given a reduction in reflected mechanical "noise" energy. Although maybe bearings last a long time. I'm new this hobby... Loved the holistic medicine comment... :-)
Been doing this for months... it cured a mid throttle oscillation on one of my quads... Car engines don't just sit on rubber mounts. the bolts go all the way through also.....
Hahaha, the first 10 secs... hilarious! I'm going to soft mount my Racerstar RF2205S 2205 2600KV now. Even though the Flip32 F4 has a MPU6000 via SPI i got heavy jaw twitching as a result of heavy motor noise induced mid throttle vibrations. After soft mounting the FC with o-rings the quad now behaves exactly like the Wizard in the beginning of the clip. After watching that video i'm sure that soft mounting the motors will get rid of those little yaw twitches that are still there. I was hoping for cheap replacements with those motors, but they quit making them last month or so. So i'm left with cheap, awful, noisy motors that i can't even replace when they fall apart, damn Racerstar for that!
the problem with soft mounted motors is that you don't get stretch on the bolts. it makes them prone to self loosening. there needs to be a soft mount solution where the screws can be torqued without that compressing the soft mount. like old servo rubber gromets that had brass sleeves to drop into the rubber. I thought about buying shouldered bolts but I can only find short m3 or bolts in stainless steel for $3-$5 a bolt which would be cost prohibitive.
Shout out to all my haterz
Oh come on, you don't have any haters
I'm not one, I agreed with you when I first saw your video.
Hahahaha! Feels good, doesn't it?
now you should soft mount your glasses, so juice doesnt splash out when you put them on the table.. hence #evenmorejuicy
Johnny FPV my hats off to you sir
As an engineer myself, I applaud you for answering the mail with some science. I am upping my Patreon contribution.
I'm an Aerospace engineer and I just discovered your channel as I was doing research to pick up my first hobby-grade multi-rotor. You've definitely got some good stuff and I think you are spot on with this video. Multi-rotors rely on their FCs to stay in the air and the better the data going into them, the better the FCs can manage the overall performance of the vehicle. There is a downside to soft-mounting, though.
The soft-mount trick works because it allows the motors and the props to "wiggle around" on their mounting pad, so the mounting material actually absorbs/damps out a lot of the high frequency vibrations originating on the rotor side of the interface, such as vibrations from an iffy bearing. The problem is that this also allows the rotor head to slightly change angles based on the vibrations being generated by the system and the larger torques being created by the motion of the aircraft.
These motions should be pretty small, but even a few fractions of a degree could be enough to cause the control logic to have to take action to actively try to suppress this motion in the control loop. Will you feel any of this action? Probably not. However, it could result in a slight "softening" of some of the control inputs by introducing a slight "lag" in the control channel. Imaging the nice rigid rotor arms are flapping around slightly under load, so it takes a fraction of a second for the system to settle down and return to a steady state when it is upset or you introduce a new control input.
Again, this will probably be way below the threshold of what most folks would notice, especially for a vehicle in this class, but it is a real byproduct of having anything "soft" in a system that expects everything to be rigid.
Again, great video! As a noob to this corner of RC, I have learned a lot from you so far.
"Take it from a guy who's looked at alot of black boxes" could be the best out of context line ever.
Glad I'm not the only one who laughed at that.
"Johnny says it makes his quad more JUICY..." Best quote of 2017. 😂
Charpu tape just went up to $30 a roll now.
The comedic value in the first part of this video is beyond words....
I learned this years ago when I soft mounted my wife's thunder stick 2000 to the headboard! I have slept like a baby since lol good stuff man thanks for sharing this information with us 👍🏽👍🏽
Don't worry, pal. This comment didn't go unnoticed 🏆
I enjoy listening to you Joshua because you keep talking without stutter,coughing,excuses of any kind and distracting from the subject.You have a knack of keeping to the point and my attention.Good job sir.As far as the vibrations are concerned I’d say insulating the arm to the frame ,if possible would be less tedious and also the motors can still keep their ridged mounting without the wobbling.
Don't let theory ruin a good experiment! AWESOME! I get excited when my hypothesis is wrong! Most people try to force their hypothesis into the result. Not good science folks. Your killing it as always Brother! Keep it up.
Follow up video, TPU, foam tape, electrical tape and hard-mount shootout ! We all need to know :D
Soft mounted my tv, inauguration is still on.
Myth busted.
yep, it won't filter that much noise
My god, I think I just snarfed a cheese sandwich.
GAPiT FPV Don't remind me of that overgrown baby.
This is bs😂...ha...if it doesnt work for tvs then definitely wont work for quadz
Finally a video with some objective data and proofs. Thanks Joshua.
Instead of electrical tape I'm planning in using silicone backing sheets, 1mm thickness.
Softer, cheap, doesen't leave a sticky mess and is high-temperature resistent.
Also, I think is better using only 2 screws for motor (A' la FGA or MrSteele), it will give more wiggle room.
Edit: [On a side note: If you find the perfect silicone backing sheets already in your kitchen, better ignore them and order some new one from Amazon. Your significant other may disapprove.]
Thanks much again for your (very valuable) time Joshua.
Just at the first motor here. The tape I had sitting around here in OZ is Scotch Outdoor.
Cut mine at about 60mm before folding to create a couple of small outer corner 'bumpers'.
Thanks Joshua. I was anxiously waiting for your test, but was thinking "Joshua wouldn't touch this topic with a ten foot pole, would he?". Anyway, great results! A couple of us did post similar controlled tests on Facebook, which confirm your observations. Most who payed any attention to it were convinced instantly, but the vast majority were laughing too hard to notice.
Thanks Joshua. I'll try this tonight. My quad flew away yesterday but lucky it went directly straight up to the sky since I was hovering. My setup is Emax Eco 2306 2400kv, Spedix GS45 4in1, Hyperlite F4 OSD v2 flight controller and 6" props. I could not believe what I saw and heard in the span of 2 seconds. I was hovering the quad and it was about 10ft away from me when suddenly, it flew to 150ft high and I was so friggin scared since I'm a newbie to this. I wasn't aware that flight controllers should be soft mounted. I was told yesterday in one of the Discord channels. I'll fix it later. I'll try soft mounting the motors too, Thank you Joshua!
Hello Josh!
Saw this right now here in 2018 and i do have some technical knowhow in filterdesign to share that might help understand why there are still noises in the Gyro Signal (also an idea on how to reduce vibrations even further).
Filters in genereal:
There are basically two kinds of filters, HIGH PASS Filters which cut out only low frequencies from a signal, and LOW PASS Filters which cut out only high frequencies. You can also combine those two Types (but that doesn't matter here).
As you can imagine, what is used in the gyro-application is a LOW PASS filter, as we want to reduce high frequencie noises that mess around with our gyro-feed.
The reason why you still have noise after the filters are applied:
However, the term "CUT OUT a frequencie" doesn't really apply to what a filter is able to do. Filters, no matter if analogue or digital (what is used in every gyro application for quads) can only dampen a noise down to a level where it doesnt matter anymore, and they do it gradually from a fixed frequencie on. (See: upload.wikimedia.org/wikipedia/commons/thumb/6/60/Butterworth_response.svg/350px-Butterworth_response.svg.png After the fixed Filter Frequencie (cutoff frequencie in the graph), the damping is not straigt, it is gradually)
The gradual decrease of the noise intensity above this fixed frequencie is the real reason you can still see noise after the filter applied, because it is simply too close or even before the fixed frequencie.
Other Way to reduce vibrations (not tested, since i never flew anwhere else than in the sim lol):
To do that, you could also try to softmount the arms that hold the motors. This approach is not possible with every frame, since you would need the arms to be mounted individually, but it should work on the wizard.
I watched this video the same day it was posted but never soft mounted my motors out of laziness... I soft mounted them today and just WOW!! It really maid a difference. I had some problems with vibrations and I had soft mounted my FC but it wasn't enough and soft mounting the motors really got the problem fixed.
THANK YOU! Finally, someone with a voice mentioned the surface area factor. Now, back to our regularly scheduled arguing on the Internet.
I found that drop of oil (corossionx) on noisy bearings works very well on removing micro vibrations and mid throttle oscillations
fpvYou interesting use of Corrosion-X. Do you need to re-apply bearing oil afterwards? (Like how a more refined oil will act as a solvent on a less refined oil -- I don't know how Corrosion-X compares to bearing oil like Scorpion.)
no. They state they are "World's Greatest Lubricant"
Joshua: Thanks for sharing. The world is better thanks to people like you.
Mr. Bardwell, I've been experiencing crazy noise in my FPV goggles, especially when at high throttle punch outs. I've ripped my quad apart so many times in an attempt troubleshoot the issue but to no avail. I switched cameras rerouted wires and still nothing. I was beginning to believe that it was my PID settings. At the time I was using Cleanflight but recently switched to Betaflight. I finally got my quad to fly super buttery and locked in, but the damn FPV goggles still had a isht ton of noise.
I finally soft mounted my motors and now my video feed is solid. Thank you. I also like to thank you for many of your other videos as well. So thanks again! I'm in Sherman Oaks and would love to rip with you one day.
Best regards,
-The First African American Quad Racer -
QUADristotle
Excellent. Glad it made a difference for you. You can also add capacitors to your ESCs which will probably fix the noise, if you didn't do that already.
I do in fact have nasty vibrations in my Tarot 130. 2 motors came buttery smooth, 2 sound and feel like the bearings have rusted out! Will try this and report back. Thanks for taking the time to test this and report back to the community.
Better to replace the bearings, but this will do in the mean time.
Dude. I haven't even listened to it all the way yet and the beginning is awesome.
Ok now that I have watched the whole thing, that's really telling. I suspected that we would see results like this after thinking it through a bit. It's the same reason electricians put rubber grommets on big transformers when they hang them. It dampens the vibrations and keeps the "hum" down.
Willard, Johnny and Kevin all had vids about the same time on this - good flight videos after doing it but no empirical data.
Again, thanks for performing the test and publishing Joshua, this is exactly why vlogging _ISN"T_ killing the hobby but instead educating and making everyone a better pilot.
Vlogging with information is fine. Just because a guy is on camera talking doesn't make it vlogging. I am personally bored by vlogging about vapid stuff, but to each their own.
agreed, everyone has their own reasons for watching what they do watch
@Joshua Bardwell: I´m working as a engineer in the semiconductor manufacturing industrie and know "a bit" of PID, gyros, dampening, dynamics of vibrations etc. Because to produce wafers you realy need a good understanding how to keep your PID controllers dealing with the slightest vibrations. What do you think why it´s possible to do lithography in some nanometers resolution to produce computer chips? :-)
I´m realy glad you did that video. After all the haters and people knowhing nothing about this just laughing and shouting "hypetrain" you did a great job showing the results. You´re right with most of your assumptions and did a realy great video.
There are some other reasons why the connection of the screwheads are not a so big deal, not only the surface area, but your conclusion is damn right. Of course soft mounting is reducing the vibrations that your PID controler has to deal with. And of course, some people will feel a bigger effect that others, this is not only because of the motors, but also about the frame design. There are even enough quads with so less vibrations, that the gyro filters will output a clean enough signal.
The most important thing beside getting rid of the vibrations is, that you indeed (in some cases) can tune your PID´s much better, resulting in higher P and lower D and a better tuned quad.
I´m personaly sick and tired of discussing with haters who do not even listen and trying to understand, just trolling around and making jokes of others. Just look at all the jokes and memes in the Facebook groups. :-(
Nice Job Joshua Bardwell, you have one subscriber more.
Just one last hint: If you look at the spectrum of the vibrations without soft mounting, you may notice that the biggest amplitude varies in frequency between differend quads. If you would like to push the soft mounting further you could do that with selecting different hard soft mounting materials, because they will dampening better on specific frequencies. This can be achived with polyurethane elastomers in different shore hardness.
There is no vodoo, this is just known engineering in some industries. :-)
Keep on with your great videos!
This has transformed my quad video footage. Had some similar tape at home, used it on the wizard which had suffered vibrations after a crash and now the view through the runcam eagle is silky smooth. Thanks for the vid!
Glad it helped. Your gyro is probably happier too.
I beat the hell out of my quad, fly PC props and don't change them often, and I don't like swapping out motors once per month. I had great results from the electrical tape trick. However, after exposing my quad to moisture and mud and abuse, the tape started to peel and trap dirt underneath. Last night I applied 5 coats of liquid electrical tape to my mounts. I'm pretty happy with its adherence to the carbon fiber, and it even coated both sides of the screw holes. I'll be giving it a test fly today. Thanks for your comprehensive workup, Joshua!
+ATA FPV some people are using TPU mounts.
Joshua Bardwell I might try some on my next build. This frame is nearing the end of its life so I wasn't worried about applying an experimental goop.
Thanks Joshua! I have a friend who soft mounted his motors. His hd footage before showed blurry leaves on trees but afterward the leaves were crisp. Thanks for the black box backing to support his experience!
That's a benefit I don't see mentioned much in the discussions of soft mounting: less jello in HD camera footage.
Thanks, Joshua, this is very compelling data. You are the Galileo to all the Aristotelian pundits out there.
Dan Milliron that's why I actually started following discussions on the topic. Otherwise I might've just thought it another trending hashtag
Now the verdict has been finalized. I guess people will use torque hex key on specification material(e.g. silicon, tape, washer, etc) to fine tune the softmount. Sooner or later, there will be specify products for the softmount
Thanks for this vid. I like the fact that you take the time to show us these theories and whether they work or don't work, rather than random pilot on the internet saying "it works" or "it's b.s." Without any real evidence.
Mass vs. Vibrations; if the mass of the entire frame is isolated from the motors but hard mounted to the FC we have the mass working for us. Alternatively, when the entire frame of the quad is vibrating along with 99% of the mass and then we expect the mass of the soft mounted FC ( a few grams) to stabilize on a few o-rings we get very poor results. This makes me think of back in the day when David Windestal started making his Tricopter frames, the camera plate was suspended from the flight frame and included the mass of the battery. Now off to print some flexible motor mounts!
Thanks for bringing this to light Joshua, not all of us have time to lurk in the forums or the tolerance to wade though people's BS! :-)
Great idea Joshua, people in general DO forget the physics behind many things in the RC world.
Great advice, even if it's old news.
Thank ya sir and...See you in the air.
Wayne
Great explanation. When you put it in terms of surface area contact it makes scene. Also, Data does not lie. Thanks,
Awesome video Josh. I like your comedic additions, namely your opening and homeopathic comments!
Not to mention your clear explanation of why soft mounting isn't BS. Sadly I think most of the soft mounting haters on the rotor riot Facebook group are not the kind of people that enjoy your nuanced and scientific approach to these kinds of questions.
Much easier to just make a meme than think critically
you fixed my oscillation problem with the x220s. i had the exact same double sided tape and it flies so stable now!
+1 on the soft mounting motors. Had a frame with yaw twitches I couldn't resolve. Soft mounted the motors with electrical tape after watching Johnny's video, and everything is right with the world again. Definite +1 on the need for loctite however. Only 3 packs through the quad and everything was coming apart.
To prevent the heads of the screws touching the arm, you can apply a spring between the head and the arm. By choosing the strength of the spring, you can also define the force of pressing the motor against the foam. Maybe a "Tellerfeder" (sorry, I don't know the English word) can also do a good job.
The same reason why cameras need soft mounts.
boom
I asked you the other day about soft mounting motors . . . I got the rubber one's off amazon. . . . Currently not using them because I'm one of the people who aren't really having that problem. . . And they are a HUGE pain to get on correctly . . Then you run the risk of motors flopping off . . . And were talking about super glue . .. my quad flies fine . . Thanks for the advice !
I've been curious what the black box data looks like with soft mounting. Thanks for doing this experiment!
Finally! Somebody did a proper video on this! Gonna have to give it a try on my quad as well now. Might not see any change right now, but as my motors wear out and get noisy, this should help keep it flying the same.
3m 4010 clear mounting tape works great. When a similar discussion went on in the rx helicopter world it was settled(mostly) that this is the best tape to mount gyros and flybarless units. I've been using it to soft mount my motors and it works well for me. Like the grey stuff it's a bit thicker than 4 layers of electrical tape but it compresses without loosing its ability to dampen vibrations. I am curious to see how the 3D printed mounts work since they would be much cleaner and easier.
Use a slightly longer screw and "soft mount" the screw side as well then you escape the contact of 1 axis of the screw. Bore out the holes in the frame and line it with mounting tape or plastidip, then it is fully isolated. Has anyone seen a spring setup? Having thoughts of the old car cd changers that still skipped. All this makes a difference but how much? Most of us are park flyers not aerial photography pros, so is it worth it for the hobbyist? FPV racer? Would be interested in seeing fpv with the data of each in a more controlled setting ie indoors with set parameters like a warehouse loop. Thank you for making great content, super informative. You Rock!
Perfect timing on this vid :) was going to soft mount tomorrow in together with an motor swap. with you confirming the possible benefits I got some new thoughts on how I'm going to do it. I run an tricopter with bracket mounts and the fc is fixed to all. RxExplorer mini. so you gave me thoughts of the end mounts of my boms :) Keep up the good work and help us thats new to this :)
I've been doing this for a long time, even before it was talked about like now, the benefits became clear very quickly. Now I can even buy pads specifically for this on eBay. Place them under the motors and with the motor protector under the arm the screws even tighten onto that, not the carbon. You can heard the motors sounding cleaner in the air, to me this is a must because of the benefits I achieve.
Making some spacers out of NinjaFlex would be interesting.
ill have to print some and see
Great information. Time to cast some polybushes and drill out the mounting holes so even the screws don't touch! PU is available in a range of hardness grades.
I build my micro quads from acetal because that's what I have available and I can cut it on my laser. Many people have been sceptical of acetal because it is not as stiff as carbon. However for a micro I think it is stiff enough. The fact that it is more flexible than carbon might mean less vibration is transmitted to the FC.
"It Done Got Better".LOL
Great analysis as ALWAYS!!!!
Thank you So Much for taking the time to actually show us some RAW Data!!!:)
You are Sharp as a TAC My Friend!!!
BTW. Thanks *Johnny FPV*, and *Willard FPV* ALSO!!!
Have a go at putting silicone washers under aluminium 'cone' washers on the bolt side of the arm to supplement what you've already done.
I've done so in the past while playing around with reducing vibration for an APM board (with mixed success). It would be very interesting to see what data comes out a black box log with modern hardware.
Love your videos man - you've got a rare combination of brains and humor - keep em coming.
Hey Joshua! Great video as always! We featured this video in our favorite drone videos of January! Thanks for making such awesome content.
Awesome! Thank you!
Thanks for the info. heading down to the table to soft mount the motors.
I read somewhere before, yes 2 years ago, I think 3 years ago either about soft mounting these motors. This was when we still fly these 450mm hex, octo, all those bunch of big multirotor.
Technically you could even soft mount the screws. Apply the dampening tape also on the bottom side and fabricate a round plate with four holes for the screws to fit over it. The only surface that the screws could touch the arms now is with the thread itself. But you could easily eliminate that with drilling a bit bigger holes in the arms....
LoL at the beginning.
I have similar shakes at around mid throttle, but the gyro traces are really clean. Haven't been able to tune it out and have been at it for months. It was buttery smooth with my earlier setup 20A little bees and 2204 Cobras. After switching to Xrotor 20A micros and Emax RS 2205 the shakes started.
Thanks for taking the time to do this experiment and post your results. I think I may give the soft mount a try with the same tape and see if I can tell a difference. I'm running the TBS Powercube on my builds and for the most part they fly smooth, but curious to see if this makes things even better.
awesome. I was too lazy to do this myself. I just tested a 1.5mm TPU pad on my motors but I need to get longer screws to feel comfortable. So ideally, the motor screw holes should be outside the base of the motor because then you can use a lock nut and then you don't need to cinch them down so hard.
Totally makes sense to grab the problem by it's root.
Since the motors are the cause of vibration.
If I had a bucket of water with a hole in it I would also concentrate on fixing the hole instead of topping of water to keep it full.
nice with blackbox that's the great proof with results! awesome job!
Engineer tip: Soft mount screw head as well, of same thickness and same material ideally :) Oring or 3d printed, you will have to find the right thickness, try slim and increase little by little :) i'm currently working on TPU shell print filled with soft silicone, but O-ring 1mm diam worked best so far.
Soft mounting helps in isolating vibrations. Best example is how am engine is mounted to a car ( with a soft rubber bush). I am a mechanical engineer myself. To those people who say heads are still touching, just squeeze the motor towards the frame, you can see the head coming out a little bit. That play (the mounting tape) absorbs a lot of vibrations. It's physically proved. It's not just imagination of bling belief..
Very nice. Thanks for speaking on this. I soft-mounted mine and thought I could notice a difference, but also wasn't sure if it was just in my head. haha ... thanks again!
finally thank you. I've been saying this since day one...not all gyros/quads/motors are gonna be the same and notice the same improvement gains!
This reminds me of the historical break-through in development of supersonic flight, where the first aircrafts were vibrating to the point of destruction.
Until somebody figured out the trick that individual parts should not be coupled tightly: the tighter the coupling, the larger the amplitude at some resonant frequency specific to the aircraft as a whole (instead of small amplitudes of many frequencies distributed among many parts if they are not tightly coupled together).
3M Illuminati confirmed! :P
Joshua, you are, and continue to be a tremendous asset to the hobby. Thank you for these investigations you do.
Depending on the density of your pad layer, there will be different torques that will take advantage of the padding used. Basically you want it firm but not tight tight..
Soft mounting motors is a way better idea than soft mounting the FC. There is no mass in the FC so it will still jiggle with the rest of the copter, but if you hard mount the FC and soft mount the motors, the FC is attached to a large mass and large masses don't want to move because physics. Hope this makes sense.
I printed my own and it 100% worked for me . Had yaw twitching on my Connex quad, put them on, boom no twitching at all. I don't care if trolls joke about it, I now have it on all my quads and I am happy :)
P.s. I was dubious too.... as you say screw heads still touching WTF? Well it works so I dont care!
Great vid! Very factual AND helpful! Thanks for taking to time to do this experiment. I'm gonna give it a try!
Your videos are amazing! Thank you for being so scientific in your processes. Too many multirotor channels lean hard on their opinions vs objective results. Subscribed!
My quad flys so much better since i softmounted! really happy with the difference!
You are a master of tuning josh! I would kill to get a glimpse of your final PID's for the wizard
Mine came with 2 really bad motors as well :(
I spent a great deal of time on this issue in respect of tail rotor gyros for model helicopters back in the 1990s and I'm convinced that isolating the motors from the frame is a better solution than trying to rely on soft mounting of the FC on its own. My reason for saying this has several factors. Firstly, the range of frequencies of vibration in the airframe with the motors hard mounted is wide - the beat frequencies can obviously be anything from zero upwards. When it comes to soft mounting the FC you have two competing requirements - you want the FC's attitude to accurately track the attitude of the airframe that, in rapid roll, pitch and yaw accelerations (OK, we old heli guys will tell you quads don't really do decent yaw acceleration but I digress 8-)=) requires a low compliance to the mount while the need to isolate low frequency vibrations requires a high compliance to reduce the resonant frequency of the mount.
By isolating the motors from the frame you are only needing to isolate the relatively high frequencies of each individual motor and not the much lower beat frequencies that exist in the frame with hard mounted motors. I think this easily explains why, despite the motor being quite firmly mounted, you are getting a significant reduction in the low-frequency components in the gyro traces.
There is another effect which I think explains why you are seeing the relatively slow meanderings of the raw gyro traces (especially the yaw axis). This arises from the fact that, although the sensors are 3-axis, each element of the sensor is actually only a single axis device - sensitive only to rotation about the axis it is currently pointing. The effect of this is that simultaneous vibrations in pitch, roll and yaw can cause a single axis sensor to have a non-zero mean output when there is no net rotation about its nominal sensitive axis. To see how this comes about consider the following movement of the quad and consider what the yaw gyro actually sees.
Tip quad 90 degrees nose down
Roll quad 90 degrees right
Tip the quad 90 degrees nose up (back to level)
Yaw the quad 90 degrees left
The quad is pointing in its original direction but the yaw axis gyro only saw the last of these motions and its mean output through this sequence is thus displaced to the left!
The important thing is to realise this happens to a degree even when the angles of motion in the three axes are very small. So when you have the sensor experiencing simultaneous vibrations in all three axes its output will generally be displaced (the degree and direction depending on the amplitude and relative phases of the pitch, roll, and yaw vibrations and this accounts for the stochastic nature of the disturbances). The result is to get small amounts of drift in the yaw axis (reduced if there is a magnetometer to give another heading reference to add to the Kalman 'mix'). Twitches in pitch and roll are also to be expected as it takes time for the accelerometers to take gyro errors out via the Kalman filter.
The final important point is that this vibrationally induced drift effect occurs even if the individual gyro sensors are “perfect” i.e even if they don't have any g-sensitivity or out-of-axis rotation sensitivities.
Interesting Joshua! I have some similar tape laying around. I think I'll try this. I love the data driven analysis!
Quality!! 😁
Very much enjoyed watching. And a I am not only talking about the purely scientific part of "measuring".
Received it as more entertaining than potentially initially intended by you.
Very good!
Idea: Soft mount, plus David W's zip ties instead of screws (very small zip ties). Quick repairs after crashes. Possibly less motor damage.
Should do an updated video of this with modern tech to see if the difference is noticeable at all anymore!
i have bad quality bearings in my unbalanced crappy le todar 2204 motors, i tried soft mounting and it helped a lot. got more power too because the FC now knows what to do :)
JUICY!?!?!?!? Doing this on my F80 rig right now as I wait for my PDB . . thanks!
Awesome video! Actually never heard of it, not that big in flying either so it doesn't matter much =D But I've learned something!
Just a question though, could you perhaps take one layer of foamtape on the underside of the arm as well? Together with some washers or anything else needed so that you don't jack up the tape of course. Could that help even more perhaps?
I'm certainly not saying that the screws are touching the frame, cause I think your results are really awesome! Actually I thought this was a "trolling" video at first, but apparently not =) But I mean, for those who think it does so much difference, could you try and make a video with one layer of foam tape on the underside of the arm as well?
If you get what I mean ;)
Anyhow, really awesome video! Never thought or heard of this before, but certainly.. Why not? It surely does some difference! You got yourself another subscriber also =)
Yeah I think you're right, it makes sense to have it on both sides. Because there is only dampening happening in one direction of the screw axis, and the other direction would be hitting on the frame. Perhaps either more dampening tape etc on the bottom side, or a spring washer with a decent K to 'pre-tension' the dampening.
Late reply I know, but im about do do my first build.
Thanks for sharing. Very interesting. I started FPV back in 2012 when things like the QAV400 were the go to FPV quads, which back then was actually described as a small aerobatic frame, ha. Most of the popular frames around then had soft mounting built into the design. At the time I just figured they stopped including it in designs because software and filtering had improved and 250 miniquads didn't need it because of the smaller scale.....obviously not entirely true.
I think maybe the Blackout 250 miniquad (now old too) moved the trend away from soft mounting and vibration dampening. When the Blackout 250 came out people were mostly using smaller 1800 sized motors on it. I guess now that motors have gradually moved back to larger sizes with bigger magnets and more torque; vibration issues are coming to attention again.
Wonder if frames will start to move back to including vibration dampening into the design.
Soft-mounting is exactly the same as low pass filtering. It introduces delay, too. Don't do it unless you need to.
I think the long arms you see on some X quads adds to the vibration issue? Remember kiddies the arms don't actually have to converge to a single point to have 4 way equal motor spacing. It is just as valid to have arms mounted like the classic Blackout miniquad and have shorter stiffer arms. You could also argue the arms converging directly under the FC almost directly couples the vibes to the FC without any of the inherent damping the frame would have if the arms did not converge at the center. Basically I am saying converging arms are a backward step in frame design.
great work Joshua, really awesome way to provide tangible evidence using BB. Love it!
Off to go try my own experiment now - easy to do on most of my quads & compare the results.
Excellent presentation.
From the first time I saw the soft mount videos, it made sense.
Will I do it? Probably not. I'm not that good a pilot and I don't race, yet.
All my birds are low budget quads. So I don't really think any amount of insulation from vibration will make much difference.
But for those that have spent tons of money on their gear, this should probably be something for them to try.
There will always be naysayers. That's the way the internet rolls. :)
Awesome video man. we need to get Steele to try this. he doesn't believe it will make a difference
Use a few layers of an old bicycle inner tube ! It’s GOOOD
Interesting. Honestly, I don't do race and not an accro flyer. Most of my quad are big size and I mainly do aerial photography or just flying around for fun. The idea of soft mount should help reduce vibration from video too as it did to gyro. My smallest quad is a 260 running INAV.
+Witit Pienchob yes, I assume this will still help with larger copters.
Hi Joshua and everyone, has anyone thought of using the rubber self-vulcanising tape to soft mount. Its the stuff they use to wrap wiring harnesses etc and can be bought from most electronics stores and auto stores.
The other question is, have you thought about putting one layer under the motors and one layer under the arms between the led plates? with a quad like the wizard you have the perfect plates under the arms to hold the bolts, maybe insulation on both sides will dampen all vibrations. Maybe the little silicone o'rings we use to soft mount the flight controller would work well on each bolt too.
food for thought.
its funny you used that tape, as its what I have always used to softmount FCs as well as generally just stick down vtxs, escs etc.
I finally encountered the 6500 gyro mid throttle oscillation too, FC was already softmounted but still had the issue, so I used this same tape to softmount my motors.
it was a definite improvement, but unfortunately, not enough and I had to goto a new FC. left the motors soft mounted still.
would actually like to see someone release softmount pads with pre cut holes, would make life easier
I printed up some soft mounts out of TPU - that worked really well for me. Just as an option as people explore - I dont like the tape option as it seems these will break down fairly quickly, TPU should last quite a bit longer. Thanks for the vid! :)
Screws touch bottom plate, but the motor doesn't, therefore the screws are able to move ever so slightly and reduce transmitted vibration.It's little stuff that make a huge difference, such as tiny little blobs of blue epoxy on motors to balance them.
It seems intuitive that soft mounting would have an impact on bearing life, given a reduction in reflected mechanical "noise" energy. Although maybe bearings last a long time. I'm new this hobby... Loved the holistic medicine comment... :-)
WOW, now we are talking. Great comparison. Finally a good proof for soft mounting motors. Now we can use bad bearings and props :-)
Thanks for going through the trouble to test this theory. I really like your channel, keep up the great work.
Been doing this for months... it cured a mid throttle oscillation on one of my quads... Car engines don't just sit on rubber mounts. the bolts go all the way through also.....
Hahaha, the first 10 secs... hilarious!
I'm going to soft mount my Racerstar RF2205S 2205 2600KV now.
Even though the Flip32 F4 has a MPU6000 via SPI i got heavy jaw twitching as a result of heavy motor noise induced mid throttle vibrations.
After soft mounting the FC with o-rings the quad now behaves exactly like the Wizard in the beginning of the clip.
After watching that video i'm sure that soft mounting the motors will get rid of those little yaw twitches that are still there.
I was hoping for cheap replacements with those motors, but they quit making them last month or so.
So i'm left with cheap, awful, noisy motors that i can't even replace when they fall apart, damn Racerstar for that!
the problem with soft mounted motors is that you don't get stretch on the bolts. it makes them prone to self loosening. there needs to be a soft mount solution where the screws can be torqued without that compressing the soft mount. like old servo rubber gromets that had brass sleeves to drop into the rubber. I thought about buying shouldered bolts but I can only find short m3 or bolts in stainless steel for $3-$5 a bolt which would be cost prohibitive.
If you use soft mounts, you must use blue loc-tite in my opinion.