RCTimer ASP driving me up the wall

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Ok, I'm running an out the box RCTimer ASP (RCtimer martinez controller, v49), with a nex5r, standard lens. It's fed from a 12V BEC (Gryphon).

I've got roll totally locked in; no vibes, instant response, no lag, no over-compensation. On the tracking screen (front page of the tool) it barely moves off the baseline, even at maximum zoom. It's spot on.

The problem is pitch. I can get a rock solid response from it, just like roll...but it buzzes/vibrates badly. Scale back "D", and the vibes reduce...but now P is too high. Scale back P...and I've lost the responsiveness - it "judders" in rotation, or just gives up altogether! Scale up power to compensate...and the vibes come back. Swap it around...scale back power and ramp up P, I & D incrementally...vibes and poor response. Tuning D seemed the most effective way of reducing the vibes - but there is no happy middle ground between vibes and "too much P" oscillations. Not even a 0.1 band - it's vibes or "P" oscilations. You normally get a small "sweet-spot" between the two, but not this time.

Spent 3 hours last night balancing, rebalancing, starting from scratch on pitch...and I just can't get it. I can get it vibe-free, or fully responsive...but not both. I tried using the IMU filter, but it had "lumpy" response in both axis. The timing option as well made no notable difference.

Anyone else had problems like this on the ASP with martinez? Any tips?
 

sixshooterstang

Bird's Eyes Aerial Media
It could be several things. BEC could be giving off dirty power. Being cheap, the Martinez board gave me nightmares worth of problems including weird oscillations under movement. The ASP could have poorly wound motors. Sources of RF interference could be causing it.
 

It could be several things. BEC could be giving off dirty power. Being cheap, the Martinez board gave me nightmares worth of problems including weird oscillations under movement. The ASP could have poorly wound motors. Sources of RF interference could be causing it.

If the BEC was dirty (Gryphon, so not cheap rubbish), wouldn't it affect roll too? Roll is nailed. RF should be low too, as I have tried powering it with only this BEC attached to the PDB.

A poorly wound motor sounds like an interesting proposition. I might try swapping the motors around - if this case is correct, Roll should vibe, and pitch will be fine.

Strangely, I did some more work on it last night and the vibes reduced (but did not dissappear) when I moved the camera forward of CoG. ie remove power and it flops forward. It still judders a little, and only vibrates occasionally if you throw it around on both axis. This seems counter-intiuative; it's supposed to work better when fully balanced!

Did you just bin the martinez and go for the alexmos? Did it immediately improve matters?
 
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Michael64

Member
Try reversing the motor drivers what I mean is swap the wire from roll to pitch and in the software change the roll and pitch then give that a go and see if anything changes may be a way to sort out if its power, board and motor. Also what is the power set at and is this 3S or 4S powered. You did not say I hope you are running a separate battery for the gimbal and not coming off the main flight battery this can and will cause issues.

Michael64
 

It's running off a 12v gryphon hyper Polaris with a ferris on input wires from the 6S. I use the same bec in my other 6S quad with an identical Martinez but a gopro gimbal not the ASP. Runs perfectly well and also runs my FPV glitch-free which is why I went with it again. So 3S, I guess.
Dirty supply I understand, and I knew the risk when I decided on my "one battery" strategy. With good equipment and design, you shouldn't be getting noise "downstream" from the flight pack. And so far it's never been a problem.

Update: swapped all cables around, and pitch is still noisy. Experimented with a ferris on the pitch cable - zero effect. Removed it.
Update 2: Replaced my harder (black) vibe balls with the standard ones. It improved! It's about 80% stable now with no buzzing. Still a bit lumpy/juddery in pitch, but only if you really watch close. Will be bouncy in flight though...might get some reds and blues and experiment.
Update 3: just ordered a V2 Alexmos.
Update 4 will come tomorrow after I do a trial tomorrow (I also have a Yaw PID problem to tune out).
 

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