Gauge for PowerFin Props

[RockyMeLad]

Hi All,
Those who know me recognize my strong points... I'm lazy and disorganized. Because of these traits I needed to come up with a better way to adjust the pitch of my PowerFin Prop. My original feeler gauge would not come apart so you couldn't smoothly "stack" the necessary pieces of the feeler gauge to get the appropriate thickness. Charlie kindly loaned me his which were already separated and loose in a baggie. With my old eyeballs, trying to find the right combination to build-up the appropriate thickness was a struggle. Also I couldn't set the stack down for fear of loosing one of the blades and getting the angle messed-up. So here is my solution bassed on the premise that intervals of five thousandths are sufficient. It takes two feeler gauge sets (cheap is ok since they come apart easily). if you stack the right pieces in the correct order, you can get from.060" to .130 in .005 increments. and always have adjacent feeler blades with no gaps. Since the manufacturer's instructions indicated to start at .095", that just happens to be in the middle of the range. Aint science wonderfull?

[Brent_Brown]

I stop doing the feelers with my powerfin and use the warp drive protractor it is faster for me and works fine.

[RockyMeLad]

I must have been tired... didn't get the attachments, attached.
:confused:

Stack
Order
0.020
0.010
0.010
0.025
0.020
0.015
0.015
0.005
0.005
0.025


For example blades 2-7 totals .095"

[scott heger]

Warp drive bubble degree wheel for props is so much faster. I just don't trust those drilled holes, but like the Powerfin blades.

Scott Heger, Laguna Niguel, Ca N86SH

[Jazzenjohn]

I just attach a laser to the blade tip, point it at the ground and mark it. Rotate it to the other blade do the same thing and compare. I have no idea what the pitch is but I set it so both blades are Exactly the same and the max RPM is 6500 on the ground.

[mceagle]

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[Aussie_Paul]

John, after I have the rpm right, I fine tune the blades but I use a straight edge rather than a laser I don't have.

I don't think it is that neccessary for me to get them that perfect but everything helps with our vibrating machines.

In our gyros we have the rotor doing say 360rrpm, the prop 2200 rpm, and the engine 5500 rpm!!!!

Aussie Paul.

[Jazzenjohn]

A laser might sound high tech but what you're really doing is using it as a straightedge or an "optical lever". The laser I use cost me $8

[RockyMeLad]

Intuitively one would think/assume it ok to just get pretty close on the prop pitch adjustment. While getting the prop back to an optimum setting after alleviating the kinked fuel line, I temporarily misplaced (right under my nose...) my feeler gauge, so borrowed a bubble level device from one of the EAA guys. In my admittedly limited experience it was way more difficult to fine tune the blade position with the bubble level due to stiction (the extra resistance to motion getting started compared to the smooth sliding once there is motion.) Much easier to turn the blade until it stopped against the feeler gauge and then too, it didn't shift during tightening. The surprise was that the bubble level adjustment had significant vibration, but the feeler gauge adjustment did not. Not sure that I understand the mechanism that caused the vibration. Both techniques appeared to set all three blades to the same angle. Any ideas?? :confused: