Quad keeps “shuttering” in hover and even on bench with props off

[JTaylor]

Hello,
I have been trying to diagnose my quad for quite some time. I have soft mounted the motors, the flight controler and esc’s. I have double checked all my soldier joints. I am getting very frustrated. I just wish I could fly a smooth flight. I am not vey experienced with beta flight. I had all the electronics and motors on a different frame and switched it to a new frame due to a broken arm. Have a video but can’t seem to attach it.

With spring coming I would really like to get the kinks worked out.

If anyone has any suggestions I would appreciate it.

J

 

[cranialrectosis]

Video will really help here.

You can embed video from a Youtube account or other URL. Just upload the video to your preferred platform and click the 'Insert Video' button in the FT forum reply dialog box.

You can attach photos directly but you have to link to video.

 

[French]

Photos of the motors and electronics will help too.

You mention you’ve soft mounted your motors. How did you do that? How many screws did you use in each motor? Did you snug the motors down or are they mounted loosely?

 

[PsyBorg]

Beta flight stock pids are very soft. They are inherently wobbly to begin with as they are pretty low. If you have soft mounted everything on your quad and things like the motor are too softly mounted they will add to these wobbles. This is a common issue where the hype train meets reality.

Best thing is to go back to the basics. Specially if this is a totally new build. With good condition parts the only thing in need of soft mounting is the FC. Same with all these fancy filters. Turn all that crap off and start at tuning the quad. Get that the best you can THEN use filters to refine the tune.

In the near three years I have been flying quads I have never soft mounted anything other then O rings below my FC's or double sided tape under my Gremlin FC. To this date I have yet to touch a filter because there is no need to as long as you keep up your gear in good working order and have a solid build to begin with.

Let the debate begin..

 

[ElectriSean]

Beta flight stock pids are very soft. They are inherently wobbly to begin with as they are pretty low. If you have soft mounted everything on your quad and things like the motor are too softly mounted they will add to these wobbles. This is a common issue where the hype train meets reality.

Best thing is to go back to the basics. Specially if this is a totally new build. With good condition parts the only thing in need of soft mounting is the FC. Same with all these fancy filters. Turn all that crap off and start at tuning the quad. Get that the best you can THEN use filters to refine the tune.

In the near three years I have been flying quads I have never soft mounted anything other then O rings below my FC's or double sided tape under my Gremlin FC. To this date I have yet to touch a filter because there is no need to as long as you keep up your gear in good working order and have a solid build to begin with.

Let the debate begin..

Technically soft mounting the motors is the best way to go about it, as they are the only source of vibration on the quad. All motors vibrate, the only way to make them stop is to stop them from turning. The specific frequency they vibrate at depends on many many factors, and how those vibrations resonate depends on even more. The fact that the vibrations in your builds haven't interfered with your FC doesn't make filtering a hypetrain item or mean that everyone that has it happen to them is using crap parts, it's basically luck.

I just went through a similar experience to the OP, my new 2" Eclair build was unable to fly at all, it would just sit there twitching on yaw and and applying any throttle would make it spin out and crash. Unfortunately I couldn't find any decent way to soft mount the FC (20x20 short stack), o-rings just wouldn't cut it. I finally got it working by soft mounting the motors properly. This involved drilling out the screw holes in the frame 0.5mm and installing 3D printed TPU pads on the top and bottom of the frame. Just like magic, it flies fine

 

[PsyBorg]

So all the smooth flights people like Charpu and FGA and MetallDany did back in the days pre soft mounting anything , pre filters, and super crappy motor tech were all luck?

I'm just saying that just as in any sport, or part of life you encounter the early basics net the best results. Once you get those down it all becomes easier. For example (sorry for throwin ya under the bus Joshua) all that fancy videos on filters and tuning and black boxing over time Bardwell has done some of his videos end with the quad still shaking like a chihuahua and that is because STOCK PIDS SUCK!!! They are just a starting point (usually on the low low side) where "Most quads" can get in the air and not fry components or be uncontrollable.

The final result of jumping into all this hype stuff is what we see now, burnt up gear, bad flight tendencies, not even being able to get into a stable hover to begin tuning in some cases. Taz first iteration I built would not hover at all. It was not anything to do with the motors it was crappy carbon in the frame I bought that sang like a tuning fork. Moved the exact same components on to a different frame and it rips like crazy and is the smoothest flying quad I have to date. The only soft mounting on both iterations is rubber standoffs.

Bottom line is in my opinion is to NOT start out with all the bells and whistles turned on and HOPE yer gear flys but start out with the basics and use those tools as needed IF needed. After all no one uses crutches BEFORE they break a leg do they?

 

[ElectriSean]

So all the smooth flights people like Charpu and FGA and MetallDany did back in the days pre soft mounting anything , pre filters, and super crappy motor tech were all luck?

"Back in the day" FC firmware did a lot more filtering than it does today, so not nearly as much luck was required to get in the air. Filtering adds latency though, and people were (are) demanding less latency and more performance, so the new more "surgical" filters were developed.

I'm just saying that just as in any sport, or part of life you encounter the early basics net the best results. Once you get those down it all becomes easier. For example (sorry for throwin ya under the bus Joshua) all that fancy videos on filters and tuning and black boxing over time Bardwell has done some of his videos end with the quad still shaking like a chihuahua and that is because STOCK PIDS SUCK!!! They are just a starting point (usually on the low low side) where "Most quads" can get in the air and not fry components or be uncontrollable.

Oscillations and the vibrations we are talking about are not the same thing. These vibrations cannot be tuned out, as I'm sure you found out with your original Taz frame. This is because the vibrations are happening at the same frequency that the gyro gets it's data from. All you can do is change the frequency that the FC sees by soft mounting things.

The final result of jumping into all this hype stuff is what we see now, burnt up gear, bad flight tendencies, not even being able to get into a stable hover to begin tuning in some cases. Taz first iteration I built would not hover at all. It was not anything to do with the motors it was crappy carbon in the frame I bought that sang like a tuning fork. Moved the exact same components on to a different frame and it rips like crazy and is the smoothest flying quad I have to date. The only soft mounting on both iterations is rubber standoffs.

The burned up gear comes mostly from turning filtering off. Too much filtering only hurts performance/latency. And I'm willing to bet that had you tried properly soft mounting the motors on that original Taz frame, it would have flown fine.

Bottom line is in my opinion is to NOT start out with all the bells and whistles turned on and HOPE yer gear flys but start out with the basics and use those tools as needed IF needed. After all no one uses crutches BEFORE they break a leg do they?

IMO, use whatever crutches it takes to get in the air and learn how to fly. Expecting new pilots to dive right into PID tuning is about the same as expecting someone to be able to rebuild an engine before learning how to drive.

 

[PsyBorg]

Sooo.. going back to the original post asking for help... what would be your solution to help him since he has pretty much soft mounted the quad in every possible manor?

 

[ElectriSean]

Sooo.. going back to the original post asking for help... what would be your solution to help him since he has pretty much soft mounted the quad in every possible manor?

Since we haven't heard from the OP since the OP, I don't know since I haven't seen any pictures or videos of what he's got going on.

 

[JTaylor]

Since we haven't heard from the OP since the OP, I don't know since I haven't seen any pictures or videos of what he's got going on.

Thanks for the reply’s, sorry for the late reply but as always life gets in the way. You both bring up good points, I am running an beta flight f3 fc, mounted on plastic stand off with orings bewteen. The motors are red bottoms with blheli 30A bullet esc’s. I have used a double sided foam tape to soft mount the motors and escs. I have tried to run with the motor screws backed off but no real difference. It is mainly a yaw vibration. I found a bad soldier joint on on motor ground but it did not stop the vibration. I also notice one of the motors is warmer than the others.

I used this entire set of gear on a 250 frame then broke an arm and decided to build it onto a martian II 210 frame. I did have to resoldier a few things but no real changes.

I will try to get something up on my channel. TRazer_FPV. The videos up there are with my old frame.

Thanks again for the input.

 

[PsyBorg]

tried finding your page on Yt no luck.. says you don't exist by Trazer_FPV.

Anyway since you say one motor is hotter then the others on short flights like that It sounds like you may have a motor screw up into the motor windings, or one near the area where they exit the motors that got rubbed bare by a screw. I would do a check under magnification and look at the screws and wiring near the screws.

 

[ElectriSean]

To properly soft mount motors, you need to have isolation on both sides of the frame, and try to ensure that the motor screws aren't touching the frame. You may need to drill out the motor mount screws on the frame a little. Foam tape may be a bit thick for this, some people use a couple of layers of electrical tape. There are also pads you can buy, or you can 3D print them out of TPU if you have access to a printer.

 

[JTaylor]

View attachment 104300 View attachment 104301

 

[JTaylor]

https://www.youtube.com/channel/UC_UgMfpcw7OKRppdZRHcH8g
my channel

 

[ElectriSean]

Your attachments aren't showing up.

 

[PsyBorg]

I got to your page from the link but for some reason can not find it when I type it in the search bar for YT... That's Google for ya I spose..

Anyway I watched the last flight you did and posted two moths ago and it seems to fly fine for a newer pilot. What you are seeing is simple tuning issues and maybe too fast rates for a newer pilot as there was a bit of over correction. That could simply be the flight was LOS and would be more stable thru FPV as you could see and feel exactly what the quad was doing.

Ill log in to YT and sub you so I can keep track of progress as you post more videos.