Max
After three years /160 hrs trouble free service I removed the brush box
to verify unused lenght of the brushes. I compared them to new ones.
There was still 2/3 to go (= useful lenght) in every brush. So I
suppose it would be a good time to change them for new in F-PMLH=C2=B4s
case!
I do remember Airmaster-Martin estimated me they will last typically at
least 300 hrs. That is well inline.
BTW it was a minor 20 minutes task to take it (a slip ring brush box, it
is not necessary to open it!) away, verify and instal back (safety
wireing takes some time). Will do it every 50 hrs or so in future.
***
This was also very first time I removed also the blades to service the
blade bearings and the hub internal parts (yes =93 I know
Airmaster Service Manual call it to do first 25 hrs, 50 hrs, 100 hrs and
then every single 100 hrs). I have to say it looked a new like. Also
that red grease looked fresh and totally undirty. Anyway I removed all
grease and did all the tasks as per manual. That took a whole day long
but maybe I was extra careful /concerned. I feel it is better to do
seldom and as well as you can (if there are no marks of problems) than
often and a bit hurry. Grease I used was Aeroshell 22.
Cheers, Raimo Toivio
Europa XS Mono OH-XRT #417
Updated flight hours /landings: 258,15 /466
37500 Lempaala
FINLAND
p +358-3-3753 777
f +358-3-3753 100
toivio@fly.to
www.rwm.fi
From: Max Cointe
Sent: Wednesday, April 18, 2012 11:59 AM
Subject: Europa-List: Airmaster AP332: replacement of slip ring brishes
Hi There All,
According to the Airmaster maintenance manual (see above) the brushes
should be replaced when they are used! Has anybody an idea of
their life-time? We have nowadays 425 hours (and close to periodic 100)
with original brushes and I=99d like to avoid unplug them just to
verify.
Thanks for every answer.
Section 11.3.2. Replacement of Slip-Ring Brushes
The sensor/brush assembly brushes that run on the slip-ring will
progressively wear down, as they
act on the slip-rings. Once they have become so worn that the spring
behind them is at full
extension, they will no longer have good contact with the slip-ring.
This may be observed during
an inspection of the propeller, or may become apparent as a result of an
open circuit failure of the
pitch change mechanism (indicated by all three controller indicators
flashing red).
Rgds
Max Cointe
F-PMLH TriGear Kit #560
912ULS Airmaster 420 hours
mcointe@free.fr
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