REFLECTOR: MT elcoprop - burned out pickup - fly?

[sbjknox]

----- Original Message ----- 
From: "Andrew Judge" <ajudge at grovenetworks.com>
Subject: REFLECTOR: MT elcoprop - burned out pickup - fly?


> I've got my second burned out brush block after about 230 hours on it.
> It's stuck in a fixed position. I was wondering if anyone has flown one 
> fixed
> like this until they were able to get a new brush block. Seems to be ok 
> flying.
> Attached is the picture of it at 5000 and I got a static of 2580. I've got 
> to get to MA...

> Andy

Hi Andy,
I began having trouble with the MT prop controller on my Velocity the first 
day I owned it and was flying it home from FL.  This was an intermittent 
problem and it almost made me crazy trying to figure out the cause.  I would 
remove the top cowling and began troubleshooting and suddenly it would start 
working.  Then be ok for a few minutes or a few hours and fail again.
On mine, the brush block was mounted on an aluminum bracket with only one 
mounting point to the engine.  This allowed for excessive movement out at 
the end where the brush block was located causing poor contact with the 
slip-rings and wearing the brushes unevenly.
I bought a new brush block and modified the mounting so as to be more rigid. 
This was about nine years ago and operation has been proper since.
My controller has two switches... one to select 'Auto/Manual' and the other 
to raise/lower the rpm when running in Manual mode.  And of course, the knob 
(pot) to set the rpm in Auto.  And a light to show when the prop is at the 
max-rpm limit-stop. One can easily fly the plane in Manual mode... just be 
careful on takeoff (full power) not to over-rev the engine.

Sid Knox
Oklahoma

Velocity  173 RG  N199RS
Starduster  N666SK
KR2         N24TC
W7QJQ