Hi Mark,
I think your message proves my case.
Its unquestionably an excellent piece of kit but it does need "an expert" to
determine whether it is the prop thats out of balance as opposed to some
other problem.
Im sure though that the manual covers such anomalies.
Carl
----- Original Message -----
From: "Mark Burton" <markb@ordern.com>
Sent: Friday, June 08, 2007 7:46 PM
Subject: Europa-List: Re: } Prop Balancing
>
> 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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