APC Props

Stuka Stunt Main Forum · 11 of 11 known posts recovered

Peter Hess · Mar 25, 2001 07:44 PM

Bopping around the internet tonight, I decided to take a look at the web site for APC props. There were three props that prompted my particular curiosity: 9.5x4.5; 10.5x4.5; and 9.625x3.75. The first two were characterized as "40 Free Flight" and the third as "29 Free Flight".
Does the fact that APC calls these "Free Flight" props really mean anything? Is there any reason why these props could not be used or at least tried for control line stunt? Does anyone have experience with them?
Thanks in advance for any comments you might have.
Peter Hess

Steve Helmick · Mar 25, 2001 10:34 PM

#1 source

The ones to avoid are called "Slow Flyer", and the electric ones. They are both for electrics. What we need is wide blades. How about ordering one of those .40 FF props from one of the (R/C) mail order dealers and report back? It should at least be good for a breakin prop. Steve

kdheath · Mar 25, 2001 11:11 PM

#2 source

My sneaking suspicion is that these are intended to be high RPM props. For FF high Rs would be appropriate, what with the short engine runs. Would be interesting to see how they compare to regular APCs in blade width.

peabody · Mar 26, 2001 07:17 AM

#3 source

I have had particularly good luck with the 10.5 X 4.5 apc unit on .40's from Randy Smith,.

There are several round these parts that modify fps or fp clones to near what Randy suggests and they work terrificly on those, too! The blade is very SHARP and comes to a point. I can tell the difference when 1/8" of the tip is ground off in a funny launch! They seem to like a ground speed of 10,600.

See Ya

Peabody

Peter Hess · Mar 26, 2001 07:38 AM

#4 source

Rich: Thank you for your comments about the 10.5x4.5 on an 40 FP. I seem to recall that you have called this a "magic prop". I was thinking of trying the smaller ones on a Fox 25 BB. Do you know of anyone doing that? Any thoughts?

Leonard: What would you think about the 10.5x4.5 on your TT25 GP?

Thanks everyone for your thoughts and suggestions.

Peter

LNeumann · Mar 26, 2001 08:32 AM

#5 source

LAST EDITED ON Mar-26-01 AT 08:33 AM (EST)

>Leonard: What would you think about
>the 10.5x4.5 on your TT25 GP?
>
>Peter

I normally recommend about a 5.5 pitch as "ideal" for the engine. However, line length and prop brand will make a difference. Shorter lines will need lower pitch to keep lap times the same (and if you are flying on 58-60 foot lines, that may be the case) and props with thicker airfoil (like the APCs) will have a higher "effective pitch. These props tend to load the engine more. One way to find out, try it. If it loads the engine too much (thick airfoil) you can cut it down a tad.

I am always interested in getting reports back from people of what props work and what props don't work. Too often people just don't want to try the big props because they don't think they will work.

Leonard Neumann

Steve Helmick · Mar 26, 2001 07:30 PM

#6 source

One of the FEW things I remember from the stunt flying I did 30 years ago was to experiment with props a LOT. Preconceived ideas are difficult to get past, but you have to do it.
There was an interesting article in SN about '98 regarding how prop tip rework affected line tension overhead, control response and many other factors that you just would never dream would happen. The article was written by a member from the D.C.S.C. (is that the correct abbreviation for the Dreaded Canadian Stunt Contingent?), and there were several in that issue from them. The articles were all excellent reading. I'll try to look up the issue and post it. Steve

Peter Hess · Mar 26, 2001 08:12 PM

#7 source

Hi, Steve:
I appreciate your thoughts about experimenting with as many props as reasonably possible. In fact, my original question was part of my effort to put some reasonable parameters on that experimentation. I have put together an order that I am going to make direct with APC for seven different props ranging from the 9.5x4.5 to an 11.5x4, including a 9X6 three-blade. These are in addition to an assortment of BYO's, Maswter Airscrews, and Power Points that I have been gathering. Now, if it ever stops snowing (Yes, it is snowing here and up to 4" is possible), and as soon as I get my tachometer, I am going to have a lot of fun.
Peter

mrwhizkers · Mar 26, 2001 10:57 PM

#8 source

I've been having good luck running an APC 12x4 on a retimed FP40 using Fox 15-12-12 fuel. Also with an APC 12.25x3.75 on a retimed LA 46, again with Fox 15-12-12 fuel.

Angel Figueras · Jul 09, 2001 07:33 PM

#9 source

I am a fresh arrival into this site. My high school friend and control line mentor steered me to you. Wow! I couldn't help but add to this discussion as I have just recently returned to this aspect of the hobby and I have discovered much about how critical prop selection is to a proper stunt run.

I am practicing with a Ukey 40, a stock FP40 (small venturi, two head gaskets), Sig 10%nitro, 50:50 20% oil fuel, Uniflow 3.5 ounce tank and sixty foot eyelet-to-eyelet lines. Experimenting with props was prompted when on a funky takeoff with my beloved BY&O 11-5, I dinged the tips. I could not believe the difference 1/8 of an inch on each tip made on the line tension, engine load and overall 4-2 break performance. I agree with Steve; you must experiment.

Subsequent to this "prop bashing" I have gone all over the prop world, searching for an economical and ready replacement. Many have worked well. A cut down Zinger 12-5 to 11, a RevUp 11-6 cut down to 10.5 and so on. My experiences with APC's have been in RC and I have seen them work wonders on high RPM engines. However a line worth mentioning is their "four-stroke" line. This might be worth while looking into and I will try some of these shortly. My last bit of advice is the toughest to follow and that is to overcome your preconceptions and try something just for the heck of it; you won't believe the results!!

Angel

Steve Helmick · Jul 10, 2001 07:07 PM

#10 source

LAST EDITED ON Jul-10-01 AT 07:18 PM (EST)

APC doesn't have a "4-stroke line", you may be thinking of the Windsor/Master Airscrews, which start at a 12-6 and go up from there. I have found sources in this country for Graupner, Robbe, Bolly Clubman and Taipan props. All are nylon/glass and are good props. While the German props (first two) cost almost as much as a BY&O, they are more durable and maybe more consistent. The latter two are Aussie, and also have a good reputation for performance and excellent prices. Also, don't overlook the Grish/Tornado Magnum props. Try their 11-4 and 10-4 3-blade. Sizes are limited, but they have a rep for working well. Welcome to the forum. Steve