Prop adjustment angle

[jeffbock]

Have my model 7 just flying and find my RPM is a bit much. Have the 912ULS with 3 blade Whirlwind prop. The info with prop suggests starting at 17deg. but think this is way too flat.
Anyone else with this prop and what is working for them before I go on a fishing trip with this. Jeff in N. Idaho

[Dick B in KY]

I have the same setup on my SS7. Had the same result as you at first. Measure in 12 inches from the tip, place a piece of tape at that point on each blade and recheck you blade angle there. Being off a small amount will make a difference. After rechecking mine and getting things reset my takeoff RPM is 5600 at full throttle.

Dick B

[jiott]

I also have the 3-blade Whirlwind GA prop and I set it at the factory recommended angle of 71.5 degrees measured as follows:

airplane in flight level attitide.
12" in from blade tip
with one blade horizontal (level on trailing edge)
place digital level on backside of the blade at the 12" mark
hold tight against the backside, especially at trailing edge
adjust until you read 71.5 degrees
repeat on other two blades
This setting is a good starting point and should give you 5100-5200 rpm static at WOT. This is a compromise between climb and cruise, and I found it to be more toward a cruise setting.

[WWhunter]

Are you guys using the WW supplied wooden tool with a digital level?
I also have a 3 blade WW and I found the factory reccommended setting to be less than ideal also.

[jeffbock]

Am using the tool (jig) that came with the prop from Whirlwind and it seems to be a good method. As mentioned, I went from the 17deg to 22deg and now getting 5100 static. Weather permitting may fly tonight and see what it does in cruise.
Is there a source for the Nord-Lock washers (prop attach) other than Whirlwind? North Idaho

[jiott]

In my sequence of steps below, I am NOT using the Whirlwind supplied wooden tool; just holding the level against the blade.