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General control line discussion => Open Forum => Topic started by: Joe Ed Pederson on July 29, 2023, 11:54:25 AM
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Brett Buck,
I remember a post from a while back in which you said you had had a Sig Twister with an FP .25 and 60 foot lines. The post didn't say what prop you used on this ship/engine combination. Did you use the standard APC 9 x 4 sport prop or some other prop (perhaps a cut down APC 10 x 4 sport prop)?
Thanks,
Joe Ed Pederson
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I'm not Brett but I recommend getting one or two each of APC 9-4, 10-4 and maybe 10-3, and trying each.
For the FP-20, I know that Brett recommends the 9-4, which seems to get the best out of that engine. That combination was a bit weak for my Skyray 35, but mine was built stock from the kit by my brother-in-law and nephew and was -- uh -- porky.
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Brett Buck,
I remember a post from a while back in which you said you had had a Sig Twister with an FP .25 and 60 foot lines. The post didn't say what prop you used on this ship/engine combination. Did you use the standard APC 9 x 4 sport prop or some other prop (perhaps a cut down APC 10 x 4 sport prop)?
That was not mine, that was a series of them from Bob Hazle and Paul Pomposo. The baseline was a Rev-Up 10-4. They were all too fast stock and too fast with an ST spraybar and the stock venturi. Bob and Ted tried a "Brodak" BY&O 10-3 and that was WAY too slow. This was one of the many examples that told me the 20FP was a much better engine for these small models. The 25FP was consistently too fast and was not easily slowed down.
If I was going to attempt it now, I would probably start with a smaller venturi and a 10-4 APC, then adjust as necessary. The methodology is the same as I have described previously, get it flying in a medium 2 in level flights, and a peaked 2 in the maneuvers, if it is too fast reduce the pitch or diameter or reduce the venturi (a little bit, not 1/16"), too slow, more pitch, more diameter, or increase the venturi.
Brett
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Have any one tried an APC 10.5x4.5 with FP 25? This prop works very well with Enya SS25/30.
Martin
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Thanks everyone.
Brett, I have the stock venturi the FP .20 and .25 came with and I have two Jim Lee venturis that are both .250 and made for the stock OS spray bar. If these two venturis are too large, I'll have Jim make me a .245 and a .240 venturi.
I'll start with an APC 10 x 4.
Thanks for the information and suggestions.
Joe Ed Pederson
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Have any one tried an APC 10.5x4.5 with FP 25? This prop works very well with Enya SS25/30.
Martin
Probably, back in the day, I cannot recall the results. But both the pitch and diameter suggest that it would go even faster, and the problem is going to be excess speed. He could try it, they are not that expensive.
Brett
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Thanks everyone.
Brett, I have the stock venturi the FP .20 and .25 came with and I have two Jim Lee venturis that are both .250 and made for the stock OS spray bar. If these two venturis are too large, I'll have Jim make me a .245 and a .240 venturi.
I'll start with an APC 10 x 4.
Thanks for the information and suggestions.
Joe Ed Pederson
OK, that sounds like a good plan.
Brett