APC electric props vs MAS electric props - RC Groups
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Nov 28, 2001, 01:25 PM
Rod
Rod
Registered User

APC electric props vs MAS electric props


I would like to hear of your experience with APC electric props. I find that in the smaller sizes (10" diameter and smaller) they are very good and produce excellent thrust. However in the 11" and larger they do not produce the same ampount of thrust as the MAS electric props, using the same size prop.
I use an 11" x 7" on my MEC Turbo 10+ (10 cells) in a LT-25. Changing to an APC 11" x 7" I found that the model was much slower in flight and the take-off was much longer. Similarly using a 13" x10" with an Aveox 1412 2Y and 3.7:1 gearbox (24 cells) produced less thrust than a 13" x 8" MAS e-prop.
I was wondering if the larger blade area on the MAS props was more effective than the APC in the larger sizes, or are the APC props actually oversized? I have noticed that some manufacturers size their props smaller than they actually are, (that is a 11" x 7" is actually a 11"x 6").
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Nov 28, 2001, 03:47 PM
Ascended Master
Sparky Paul's Avatar
You might find it worthwhile to get a bunch of MA and APC props in the size ranges you want and try them all.
Only your model can "know" what it really likes!
Nov 28, 2001, 03:57 PM
Registered User
Rod,

I found the same thing on my Lazy Bee - the MAS 11x7e was much better than the APC 11x7e.

However on a funfly that I have the APC props outperform the MAS at the 12" and 13" diameters.

MMGM
Nov 28, 2001, 04:26 PM
Registered User
ScottS's Avatar
Was the current draw the same with both props? Props aren't always exactly what is printed on them.
Nov 28, 2001, 04:56 PM
BEC
BEC
Registered User
BEC's Avatar
The MA-E props are best at speeds below about 6000 RPM. Above that the APC thin-Es work much better. But I have found that you can't just go size for size.

My main example: I used to fly my LT-25 on the 12X8 MA-E wood (and I've tried the nylon version). My current prop of choice: APC 14X7 thin-E prop. Similar current draw, better all around performance (though a bit lower top end speed, which isn't a big deal on this airplane except for when trying outside loops).

All this really does is prove what Paul said - try 'em! (And I have tried several others before settling on this one)

But I have alot of MA-E props that I don't use anymore......
Nov 28, 2001, 04:58 PM
Recruiter - 60 Amp Club
Ed Lyerly's Avatar
Master Airscrew "E" props in the 10", 12", 13" diameters put out more thrust ....and pull more amps than the APC "E" props of similar size and pitch.
My experience is ( as someone else said earlier ) that it depends on the aircraft you are using it on which is best to use.
Ed
Nov 28, 2001, 05:03 PM
Rod
Rod
Registered User
Scott, I found that the 13 x 8 MAS electris drew about 42.3 amps whereas the 13 x 10 APC drew about 39.5 amps on the Aveox.
The MEC drew 31.2 ampos with the MAS 11 x 7 and 28 with the APC.
From this I can guess that although the APC's draw fewer amps, they also produced lower thrust in this prop vs. prop comparison.
Last edited by Rod; Jan 22, 2002 at 02:20 PM.
Nov 28, 2001, 05:37 PM
RIP Azarr - "Old age is not for sissies"
Azarr's Avatar
Prop for the same amperage rather than the same size and you'll see a significant performance increase with the APC "E". As Bernard said, he replaced a 12-8 with a 14-7. It's moving more air at a similar current draw.

Greg Gimlick turned me on to these at Mid America a few years ago. He had a few prototype APCs for evaluation and we replace my MA 13-8 with a 14-10, same current draw and a significant performance increase.

Azarr
www.ecubedrc.com
Nov 28, 2001, 05:47 PM
Registered User
ScottS's Avatar
Testing is the only way to really know. Like I said before what is printed on the prop doesn't always tell the whole story. I tested a APC 10x7E prop and an APC 9x7.5E on the same system. Any prediction program will tell you that the 10x7 will draw more current, but in reality the 9x7.5 pulled nearly 10% more current.
Nov 28, 2001, 06:16 PM
Rod
Rod
Registered User
Thanks very much for all of the responses. I guess the long and the short of it is to test individual props of various makes and observe the flight performance, and at the same time test for amp draws etc.
Life is sure not simple in the wonderful world of Electric Flight!
Nov 30, 2001, 09:31 PM
Registered User
MrThermal's Avatar
APC lists slo-fly and electric props in the 9x7
size range. Does anyone know what the difference
is between them ??
What I really want for Christmas is an
APC 9x7 slo-fly folder !! The price for an
aeronaut folder is way-too-much
Dec 01, 2001, 08:26 AM
Registered User
Quote:
Originally posted by MrThermal
APC lists slo-fly and electric props in the 9x7
size range. Does anyone know what the difference
is between them ??
What I really want for Christmas is an
APC 9x7 slo-fly folder !! The price for an
aeronaut folder is way-too-much
Slow-flyer APC props have a much lower max rpm rating than the APC-E ones. I think they are suitable for up to 280 or gentle 400 size use only. APC-E props can be used with any electric engine, but not with a glow one.

I believe the slo-flyer ones are slightly more efficient than similar sized APC-E ones, when used appropriately.

Stuart