My Tail Freaks out!!! Strange

[Starcruiser]

This is a good one, I think I have it figured out but wanted to share this and ask for suggestions too.

I recently had to do a minor rebuild due to a crash, so I figured I would add a few upgrades while I was at it. So I added the following;

changed frame to the FG 1.2mm one (Align)
Add a metal bearing block for the tail drive (EXI version)
Added a metal battery support with the CF tray (EXI)
Added the metal bell crank for the tail (Align)
Added the metal frame washers (Align)
Added the MH bottom plate
Servo wire braid on all leads

Previously had changed;

Main bearing holders to metal (Align)
Upgraded the tail grip bearings

Now, just got done dressing everything in and went to spin her up in the garage last night and all of a sudden when I get at 50% stick (actually about 70% due to the TC) the tail goes wacky and she starts spinning, the AR6110E starts blinking and the gyro does a reset and keeps doing this, the motor is cutting in and out too.

I figure initially the battery is low so I change that out and try a fresh one, nope same thing.

OK, I figure I am stressing a servo somewhere and I check the tail servo first, that is a bit off so I straighten this out and test again, same deal, OK perhaps it is the ESC, I have a spare and swap it out, again same deal, Perhaps the 6110E is going bad, I have a 6100E in another 450, so I pull that and copy my settings, re-bind and more of the same. I am running out of options here, I decide to put her on the bench and check current draw, nothing more that 1amp peaks, I pulled the Rx and gyro out to test them. So while these items are out I take off the mains and spin her up to see if she will do it again, nada, she behaves fine.

WTF! so I start jiggling wires and connectors, still working fine!! geeze I cannot make her fail now (on the bench). I figure the only thing it can be is interference from the metal tail bearing block when it gets up to speed, the gyro is right next to/underneath it and the Rx is mounted on the other side of the tray too. I am figuring it must be RFI , the FG frame is isolating it and the CF servo tray is conductive and is right by it, so I figure this must be it since I pulled the Gyro and Rx when I tested on the bench. I will change back to the original bearing block for the tail drive later.

I will post my results later today but what do you guys think?

[HeloJoe]

What I think is f88888888888k! That's a strange one, dude. I hate the ones that are intermittent or happen once, then not again, always lurking in your mind and all.Maybe isolating it from the bearing block will solve the problem. Definitely keep us posted.

[Starcruiser]

Well it was the metal tail bearing mount, I replaced it with the original plastic one and wala no more freak out. I ran it on the bench to full throttle and no cut outs, did it a couple of times to make sure. I then threw the blades on it and hovered it and no problems. YEAH!

I suspect it was the Rx having a fit with the RFI it was generating since the 6110E and 6100E both had issues with it (flashing led indicating LOS). I put the 6100E back in and everything is functioning again. Go figure.

I am not sure if the gyro was carrying the RFI back to the Rx since it is on top of the mount and the Rx is underneath it. But I do not want to tear the bird apart again to find out.

[Mikej]

Starcruiser,

Which mount do you mean by the "metal tail bearing mount" please - any chance of a piccie ?.
Thanks,
Mike.

[ross_badger]

I also am using the EXI metal tail block, but with the carbon fiber frame, and don't have any issues. The RX is on the electronics tray and my gyro is on the aluminum MH bottom plate. That was one of the reasons that I purchased the Spartan Quark gyro with the aluminum body, so it (hopefully) would cut down on interference issues.

Keep us informed if you see anything else useful! Good luck!

[Starcruiser]

I can put up a pix later tonight, I do not have access right now. The frame is Fiber glass (FG) and the electronics tray is still the CF one. Gyro on top and Rx underneath it the GP750 is mostly metal but I am not sure of the actual culprit, it might be both.

I did notice that the GP750 gyro will not initialize or power up if the gain lead is not connected.

The Rx was definitely rebooting since I had the LOS indicator going which I believe would reset the gyro.

Ross, your gyro is further away mine is like right next to the bearing block.


Mike, This is the link to it

http://www.xheli.com/exi250-113.html

[Mikej]

Originally Posted by Starcruiser

Mike, This is the link to it

http://www.xheli.com/exi250-113.html

gotcha - thanks

[Tomstoy]

Just a thought, try rebinding and then re-enter your info into the gryo.

[Starcruiser]

Tom,

Been there done that, I had tried that and other iedas, besides its already fixed, was the tail bearing block that caused the RFI.