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Engine basics => Engine set up tips => Topic started by: frank mccune on May 27, 2015, 05:26:14 PM

Title: Cutting down pops?
Post by: frank mccune on May 27, 2015, 05:26:14 PM

    Hi:

    I have a large stash of 11" and 12" props that I want to trim the diameter to a size that will be better suited to my engines.  I am thinking of reducing the props one inch to work well on my .35 and .40 stunt engines.  All of the props have a pitch of either a 4 or 5 inch. Perhaps the 11x4 and the 11x5 props do not to be trimmed or trimmed for the .35 engines. 

    Is there any reason that this may not be suitable?

    The engines are O.S .35 Stunt, O.S. .40S,  Fox .40 Stunt circa 1971 and H.P.40 Stunt

                                                                                                                                                Tia,

                                                                                                                                                Frank

Title: Re: Cutting down pops?
Post by: Phil Krankowski on May 27, 2015, 07:23:18 PM

You are in the realm of reasonable trimming.  I would think really hard before taking more than an inch off the diameter, but it would depend on the prop size and application.  They will not act exactly like a prop that was built to be 1 inch less diameter, but instead will be heavier and usually have a steeper pitch.

It is a lot of work to trim a box of props, adjust the tip shape, reseal if wood, and then balance.  This is the biggest reason against trimming.  In reality this is just a 4 letter word, that some consider "dirty": W-O-R-K.

Phil

Title: Re: Cutting down pops?
Post by: BillP on May 30, 2015, 08:27:39 AM

No reason I know of not to trim a prop. It may be the only way you can dial in a particular setup to your likings. I normally trim when the tips are getting ragged edges. Not all props will react the same. I trim nylon MAS 9x7 to 9x6 and see zero difference. On wide blade wood Zingers I see a change. On 10", 11" & 12" APCs I trim the narrow ends off approx 3/16"~ because they get fractured easily and see no change at all.  TF Power Props are the same.  Just go for it and see how it works for you.

bp

Title: Re: Cutting down pops?
Post by: bob whitney on May 30, 2015, 09:24:41 AM

how do you trim a 9/7 to a 9/6 prop

Title: Re:
Post by: David Ruff on May 31, 2015, 07:21:36 AM

11 inch props can work on those engines anyway

Title: Re:
Post by: David Ruff on May 31, 2015, 07:21:54 AM

Buy more props

Title: Re: Cutting down pops?
Post by: Phil Bare on May 31, 2015, 09:14:48 AM

Dang, Pops is pretty short already and besides, he would probably put up a darned good fight...................... LL~ LL~ LL~ LL~ LL~

Title: Re: Cutting down pops?
Post by: BillP on May 31, 2015, 07:14:32 PM

Quote from: bob whitney on May 30, 2015, 09:24:41 AM

how do you trim a 9/7 to a 9/6 prop

Typo...I guess a senior moment? I have no idea how the mind does that stuff..actually it was a 10/7 cut down to 9.5/7 on a Fox 50rc in an ACE T-34.   

Title: Re: Cutting down pops?
Post by: frank mccune on June 01, 2015, 03:46:49 AM

     Hi BillP:

     A typo? That is the story of my life at present.

    I just bought a new computer with very small chiclets, keys, and have developed rapidly failing eyesight.  Typos are are a constant companion for me nowadays.! Lol Is not aging fun?

                                                                                                                                                       Be well,

                                                                                                                                                        Frank