Prop Scan

[hump180]

I just had my prop scanned by Black Dog Propellers, the same shop Ron used. The results for my 15x9 3 blade are below. They are repitching to 10 from this point. Hopefully I will notice an improvement next summer. Next time I talk to Steve at Black Dog I am going to ask how a prop can be so out of spec.
Bill

Scan Results
8.4
8.9
9.2

[Ken Juul]

From what I have seen pitch is set with an angled "pitch block" and a hammer.  Slide the prop over a vertical post.  Position the pitch block under the blade and use the hammer to adjust the blade to the new pitch.  Many shops just use experience and eyeball to guage when it's close enough.  The electronic system Black Dog and others use is fairly new technology.  When I had mine checked electronically to confirm the pitch, I found I have a similiar spread, not quite as big.  I asked the shop about it, they said they would be happy to take my money.  However unless I was experiencing excessive vibrations, at the speeds our props turn a a few degree spread either side of desired is considered acceptable.

[Ron Hill]

Bill : As Ken said "they use a mallet and a pitch block" then the finished product is deemed OK by "eye ball-ing" the finished product.
I believe that Prop Scan is worth it; the pitch and twist are exacted at 3 differant places on each blade. If you don't believe it's worth it, it just ask your cutlass bearing!!