Thanks Pete!
RTFM = Read The Fine Manual (and double your mileage).
What I have found so far is that balancing a prop when everything else is
perfect
is quite straightforward. The problem with propeller balancing is that quite
often, it's not the propeller that is the main source of vibration. For example,
in the last couple of weeks I have used my balancer on three installations:
1 - A 2 bladed composite prop on a 912S - propeller needed very little weight
adding
- the real problem was the 912S inlet manifold (big tube thingy behind the
carbs) banging against an oil cooler mounting tray - when the owner sawed 1cm
off the corner of the tray, the thing went from being very lumpy to OK - 10
minutes later the prop was balanced as well. The owner was convinced that the
engine was going to have to be swapped!
2 - Airmaster prop on Jab 3300 - straightforward - started at around 0.2 IPS -
needed about 10 washers adding but finished up at 0.06 IPS - got a text message
---From the owner today - he was very pleased with how smooth it had become.
3 - Arplast PV50 on a 912 - prop probably could be slightly better balanced but
this was impossible to achieve due to some as yet un-diagnosed problem with the
engine. (PJ - you were right, it's not the prop that's the major vibration
source here).
I think those 3 are quite representive of what you see when balancing props.
BTW - If you're using my PB-1 unit then it's fairly easy to spot non-prop
vibration
right away because the graphical display will bounce around like a dingbat
and the numbers are inconsistent. If the prop is badly out of balance, the
display is much steadier and the numbers more consistent.
PB-1 owner/operators - please contact me off list if you have any questions
regarding
its usage.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=117331#117331
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