Anti-Rotation Bracket???

[RyanW]

Anyone had their swash pop out of it? I had it happen last night. Not much fun, but at least no one was hurt and it isn't completely totaled.

[Tommy Wagner]

Never heard of that any pictures


Tommy

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[RyanW]

It happened on my N9 back when they were new, hence the Hyperformance aluminum unit. It is on the workbench... in time-out right now. When it gets out I will take some pictures 

[steffgiguere]

Can't see how it could happen. On mine it's the most inner bearing that is closest to the bracket. When you rebuild please post pictures.

[RyanW]

It is still as it was crashed, so I will take photos. It definitely popped out. How exactly that happened I don't know, but the most obvious would be the edges where the bearings align have enough gap to catch the edge of the carbon. The servo output is plenty strong enough to flex the carbon forward and pop it out.

It shows in the photos where the left servo pushrod was scrapping along the top mount (can only happen if the anti-rotation portion is dislodged). It wasn't a single mark, indicative of crash damage; it was from moving up and down for a second or two.

Full story later...

[stevehof]

Maybe a slight very slight chamfer or rounding on the inside of the bracket is in order?

[RyanW]

That might help. I sanded and sealed all the edges on the carbon parts during the build (most time consuming part of the build by far). It does still have a well defined edge though.

I don't think there is anything wrong with the design, I just have a knack for having the strangest issues with my machines! I doubt there will ever be another instance of this happen, but rounding the edges a bit wouldn't hurt (don't chamfer it to the point you created a single edge in the middle though). Seal it with some CA and that should be overkill.

I am VERY SURPRISED at how well the model did with a full power impact. I need to disassemble it to get the full extent of the damage, but it appears the frames survived... which if true is an absolute miracle.

More info later...

[Matt Botos]

Hey Ryan,

That is definitely an odd one, even at the max throws I can't get mine to come out of the anti rotation bracket.

Let me know what you find.

Matt

[RyanW]

Hello,
   You are exactly right. There is no way it will come out of the bracket with normal input, even at max throw. I found some carbon shards between the bearings, which is a tell-tale sign the edge of the carbon caught in that small space, flexed forward and the next input was such that it forced its way out. I am going to disassemble it on Monday and double check everything to see if could be something else.
   The control output was such that the swash would have been rotated CW approx 30~45 degrees. Down elevator resulted in forward and right. When I put left in, it just went forward. The control arm on the left cyclic servo had rubbed against the aluminum servo support/ frame brace. It was not a single impact, but a smooth removal of finish from the control rod about 10~15mm in length and the corresponding spot on the aluminum was indented; which tells me I had a few seconds of the control rod moving up and down before the crash. The only way the control arm could lay against that brace would be if the lower/outer swash was rotated the said 30 to 45 degrees CW.
   I guess the silver lining to this, other than the obvious that everyone around was safe, is the TT conversion is coming out and I can switch to that instead of buying all of the belt components and then the TT later. Hopefully I can get my hands on one in the next week or two, as I have a demo at the OSU Speedfest the end of April.