How do you do backcuts on an x series prop?

[hugh hargett]

Just wondering if anyone can tell me how to correctly do backcuts on a stock cupped prop. I also would like to know when doing unstaggered twin props how to get then as identical as possible . Can a back cut be considered a re-rake job or are they totally different?

thanks

Hugh

 

[RodneyPierce]

back cutting a prop will essentially remove lift from the prop, and free up the motor. Let me see if I can find the article by Marty Davis on prop tweaking/cutting.

 

[hugh hargett]

No Rodney, I know what it does I mean how to do them . The actual prop work.

 

[RodneyPierce]

my bad...... 

just cut it.....  make sure they are the same on both sides and have at it.  On 21 props I usually go 1/8 inch down from the hub, 1/4 inch out from the hub, draw a line and cut away...

 

[hugh hargett]

Any diagrams?

 

[RodneyPierce]

there is an article from Marty Davis called prop tech notes or something of that matter. Search on here and Im sure it will come up.

 

[Ted buckley]

Any diagrams?

Hugh, If you have a dremel with a drum/sand paper bit(Coarse-then fine), you could do a nice job on the back leading edge. It will make the same cut on both sides.

 

[Ted buckley]

Areas to Bend Prop.doc

Just wondering if anyone can tell me how to correctly do backcuts on a stock cupped prop. I also would like to know when doing unstaggered twin props how to get then as identical as possible . Can a back cut be considered a re-rake job or are they totally different?

thanks

Hugh

Incidentally, When talking to Dan Hutchinson this weekend - he was showing me one of his props off of a twin that he had, and he just simply put (3) 3/8(approx drill holes on each side of his blade towards the top of the rear edge.. He said that it relieved the props very good.

 

[anthony_marquart]

I've seen this done a long time ago... have to think it could have some unwanted results..

 

[Ted buckley]

I've seen this done a long time ago... have to think it could have some unwanted results..

You talking about the Holes or the above diagram? Holes- I thought so myself, but he said it worked for one of his set-ups.. Dan is no sloutch..

 

[anthony_marquart]

the holes... back-cut is common,..

 

[MarkTibeau]

This might be the link.

rcboat.com/prop.htm