ORIGINAL: avrod
Matt Kebabjian wrote
Ola, you may want to twist the 18.1x10 to a bit higher pitch. Dave Lockhart has written a straight forward detail regarding twisting the 3 blades, and as resourceful as you are you can do the same on the 2 blade, I am sure. Or contact Dave .
Can anyone give me a link to Dave's article?
I found this after a search here on Rc Universe.
Heatgun and steady pressure. I experimented on a junk prop for the first one. I took a piece of 1X4 and screwed it to the side of the bench leaving a 1/4inch slot. then I made a measuring device to measure the angle of the prop and measured a target prop . (16-11 in this case) then I put the prop into the slot and applied a twisting motion to the blade in the direction I wanted to go, (less pitch in this case 13.5 to 11) and then slowly applied the heatgun to both sides of the blade in question, once the blade Relaxed and moved I applied heat for a little while longer and then let it cool while holding it slightly past the target. when I released it it sprang back a little.
I then measured the blade in a predetermined spot (so all the blade would be the same, I drew some marks on the prop and the bench)
and saw if I was there yet. once I was satisfied I set the other two blades to the same pitch while also measuring the tip hight.
DISCLAIMER_____ I DO NOT RECOMMEND THIS PROCEDURE IF THERE ARE PROP S AVAILABLE IN THIS PITCH.
APC says NOT to do this. I know Dave Lockheart sells the repitched 3 blades. and alot of the folks in the pattern community do this.
Your mileage may very etc etc....
The key is to not overheat the blade while doing this. if you get a white spot on the prop too much heat. you want to apply slow even heat to the blade.
Regards Rod
Rod,
If you are using dry heat to soften the nylon, make sure you hydrate the plastic after you are done. Stick it in a pan with warm water overnite. It also tends to stress relieve so the original twist should be just a bit more than the final you want.
You may also use a pan of boiling water to get the prop hot up and then use the heat gun to direct the higher heat exactly where you want it.
The best solution appears to have been found by Bill C....apc will probably start selling these props soon. The 18.1x12 looks real good for my Webra 160. The 18.1x10 is a bit noisy for my taste and when it was re-worked to a 19x10, it didn't really lose any noisy components. But sure has brakes!! The 12 pitch should have the best noise/brakes/speed envelope.
MattK