Gordon,
Sorry to here of your lost time with the Airmaster.
Please note that when inspecting the brushes, it has come to my
attention that the braded copper wire has to be twisted nearly to the
point of making a curl. Once nice and tightly wound, it stays inside
the spring and is trouble free.
If the braded copper is not wound tightly, it tends to bend under spring
compression and get caught in the spring, partially jamming the brush.
Normally this is fairly close to brush replacement time. Should the
copper lead get caught in the spring wire gaps, this makes the brush
hang up and eventually loose contact as it wears. I have even seen one
where the spring cut the braded copper. Either way the prop control
stops working properly shortly thereafter until the brush is changed. I
have never had problems with carbon dust in the brush guide, but that
too has been a reason for sticky brushes.
I'm afraid I have seen the wire jam up the works twice now and it really
has nothing to do with your operations. The Airmaster manual is clear
on how to wind the copper braid, but I am afraid, we don't all wind the
copper the same.
On annual inspections I tend to take my brush block off and check my
brushes carefully. Any sticking and I am into it, cleaning and
inspecting. But I am anal like that.
Best Regards,
Bud Yerly
US Airmaster Distributor.
----- Original Message -----
From: GBWFH2010<mailto:gaxuk2001@gmail.com>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Wednesday, May 29, 2013 12:37 PM
Subject: Europa-List: Re: Airmaster AC200 Feather light on during
flight
<gaxuk2001@gmail.com<mailto:gaxuk2001@gmail.com>>
I think I have solved the problem. Despite having removed the brushes
and cleaned the slip ring once, I decided to do the whole operation
again. What I found was the inner ring brush had a very sticky spring
and was sometimes getting stuck at the mid-way point, thus making
intermittent contact with the ring. (When I removed the brushes the
first time everything appeared fine so I missed the problem.) It is
possible the vibration caused by the landing run and stopping the engine
might have been enough to cause the brush to contact the inner ring as
all ground feathering tests were fine.
A short test flight showed the propeller and all light indications to
be functioning perfectly with not a hint of the FEATHER light
illuminating!
--------
Gordon Grant
G-BWFH
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=401522#401522<http://forums
.matronics.com/viewtopic.php?p=401522#401522>
http://www.matronics.com/Navigator?Europa-List<http://www.matronics.com/N
avigator?Europa-List>
http://www.matronics.com/contribution<http://www.matronics.com/contributi
on>
|