From: Mark Burton <markb@ordern.com>
Hi Folks,
>> It shouldnt be necessary as they are supposed to be factory balanced.
>
>
The propeller may be well balanced when brand spanking new but by the
time it has been attached to the aircraft and a spinner popped on the
front it is very likely to need balancing.
In the unlikely event that the prop/spinner combo are perfectly
balanced to start with, they won't stay that way for ever due to dings
on the blades. Apparently, if you take a propeller off and replace it
1/1000" out of centre then that will produce a noticeable amount of
vibration.
Mark
there are a couple of issues here, firstly it's essential to pull the blades out
before fully tightening the bolts so that they seat properly in the hub. Also
the spinner rarely goes back in the same place. The factory grp backplate is
rather floppy, to say the least. I have made graphite epoxy backplates in the
past which are at least circular, but they can never be perfectly balanced.
I have bought one of Marks prop balancers, to balance the wooden prop on my Long
EZ, so I can help people not too far from Derbyshire balance their prop. No
doubt there will be something of a learning curve ;-)
Graham
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