If you think those LED's are bad you should try a STM32 chip
So this morning was frustrating. After last night going so well with the ubmq I was really feeling hyped. Yeah, it had that odd tendency to fall out of the sky when in horizon. But it seemed to be isolated to horizon so I assumed it was probably just auto-level needing some adjustment. And it seemed to happen less if I did a gyro and accel cal just before flying. The repairs last night weren't bad (and with a few easy jigs could be made even easier) but were admittedly more work than repairs on the warp - mostly since the warp generally doesn't need repairs
So I had high hopes for flying this morning. It was a touch windy...but it the last weekend Alex is in town and the warp has no issues with the wind...why not see how the ubmq does. Once again it's no warp. It's better than my knuckle in the wind, but it's still not nearly as much fun and more work than the warp.
But I barely clocked a minute of time in the air this morning because the falling out of the sky problem was back - and is not limited to auto-level modes as the crash that grounded me today was in acro.
The first crash I didn't catch on video...or I may have accidentally deleted it...whatever happened it doesn't seem to exist in this reality and I'm not going to pretend it does. What I remember was that again as soon as I started to let off the throttle it suddenly dropped an arm. I'm pretty sure it was the back right arm - but at this point I wasn't paying close attention.
The second crash I did catch on video, you can skip to 00:30 where I actually take off, I'm still working on getting the faster computer back here so I can do some editing:
This was on my experimental profile 3 - but I flew on 3 quite a bit yesterday without this problem. And I've experienced this problem on profiles 1 and 2 as well. The first crash was similar to this only no flips. I was just doing a gentle banked turn - relaxed the throttle a bit, and fell out of the sky. This one I had just let go of the flips and recovered - let back on the throttle a touch - and fell out of the sky.
Third crash did me in for the day:
https://www.youtube.com/watch?v=SU6pBNLabYw&feature=youtu.be
Was flying full acro in profile 1 - my gentlest settings. Was just hovering. Let back on the throttle just a touch - fell from the sky.
None of the videos I have from yesterday where it happened was it close enough to see which arm. But it feels like it's always that same one.
Now for a game of cause or effect. That rear right arm has understandably been taking a good bit of abuse. But that last crash today did more damage than I expected all the same. And I found something that has me wondering if it was from the crash...or if it was the cause of the crashes.
Most apparent damage was visible before I started to disassemble, but this is a better overview to start from visually. The cracked leg is the #1 motor that I'm pretty sure hit the ground first. Screws were not damaged as far as I could tell, just the wood cracked. Don't think my second pin as a fuse idea would have helped here - it hit that arm first on hard ground with some decent momentum:
And the #2 motor was knocked off the arm entirely. Not surprising since I expected these mounts to let loose in a crash. But it's a bit worse than this photo makes it look:
Oh, yeah...that hurts. Bent both SS mounting screws. Impressive:
Ripped the screw head and part of the plastic card right through, very impressive:
So I made new motor mounts. I thought I had made some spares when I made the first ones...but I can't find them. I may have accidentally tossed them out. That's why I don't normally clean my work table
This time I tried laminating a card on each side. Thew new mounts are VERY stiff. I can put them on VERY tight and the wood just barely starts to flex while the boom starts to compress pretty well. And the screws just barely poke up past the end of the threads in the motor. So they're just about perfect. Nice little upgrade.
I haven't mentioned it but the motor mounts have been working well it seems - in hard crashes they have shifted and been bumped around but the motors haven't taken any apparent damage. Well, Maybe. This is what I found when I took the #1 motor off to replace it's boom:
The circlip was loose. Now I don't know if it had come off earlier and was the cause of the problems on that arm...or if it got thrown off in the crash. I did replace this arm last night so that clip must not have been loose when I was having the same diving problems yesterday..but yesterday they were usually recoverable - today it just fell from the sky.
I don't think it's a desync problem because it's happening when I let back the throttle not when I put on the throttle...but I'm not a descync expert or a high kv motor expert. And it does seem to be that one motor that's doing it. I should have marked the one that was a bit goofy out of the box, hindsight bah. Not sure if I'm ready to swap that motor or not. I only have so much shrink wrap and I'm going through it kind of quick replacing arms
Whatever it is it definitely seems throttle related - and intermittent. Which really has me thinking vibration....
I was using the cut down props today...but I balanced them after cutting them down and the quad didn't feel or sound like it had any new unusual vibrations.
Well, I've got new stronger motor mounts made and half installed. Have a new arm made and installed (just have to shrink the wrap.) so it's about ready to button up. Putting it off because I should install a programming header, and I really want to pick up a bit of polycarbonate tomorrow because I can't see the LED's on the afromini through the wood. It will also make the big obnoxious square design a bit less obtrusive I hope. And I like clear things.