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Old Jan 18, 2003, 02:15 PM
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alvinm's Avatar
Pembroke Pines Florida
Joined Jan 2003
498 Posts
What prop for crazy max 4.25 gearing?

Decided to see what the cm can do with this gearing,any prop size recommendations?
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Old Jan 18, 2003, 05:39 PM
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Re: What prop for crazy max 4.25 gearing?

Quote:
Originally posted by alvinm
Decided to see what the cm can do with this gearing,any prop size recommendations?
alvinm,

Try this neat WEB site at Custom Paint Job...
http://custompaintjob.com/ezcalc/dma.asp

Carlos
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Old Jan 18, 2003, 10:49 PM
Crash Master
Gene Bond's Avatar
Indianapolis, IN
Joined Sep 2001
16,632 Posts
alvinm: I think it's a 9x4.7. I remember somewhere, Mike Greenshields posted the info... I have a 4.25 on order to try.

Here's Pcalc numbers:

EM300, 3.67:1, 7.5x5, 8x800AAE
14.1oz thrust, 39.1mph, 6.45a

EM300, 4.25:1, 9x4.7, 8x800AAE
15.1oz, 29.8mph, 7.14a

Not too impressive... But, testing will see!
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Old Jan 19, 2003, 09:21 AM
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alvinm's Avatar
Pembroke Pines Florida
Joined Jan 2003
498 Posts
Isn't the stock prop 7x 5.5 ?you have 7.5 unless that is what you meant.
I currently tried the 8x6 apc and got theses figures:

Prop RPM:7125
Prop Static Thrust oz:15.3

Prop In-flight Thrust oz:7..9 Prop Pitchspeed:40.5
mph
Approx Power System Weight: 8.844 oz Batteries + Motor + 10%
Full-throttle duration: minutes 7.26
Amps were around 6
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Old Jan 19, 2003, 10:04 AM
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Gene Bond's Avatar
Indianapolis, IN
Joined Sep 2001
16,632 Posts
Quote:
Isn't the stock prop 7x 5.5 ?
Nope, just looked, it's marked 7.5x5.
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Old Jan 19, 2003, 04:43 PM
pushing both extremes
Zoom's Avatar
San Jose, California, United States
Joined Oct 2001
566 Posts
Mike G. recommended the 9x6 APC-SF and that's what I tried. It has more pulling power than the stock setup, but top speed is a little lower as you would expect. It's a good gearing / prop combo for smaller fields.

- Zoom -
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Old Jan 19, 2003, 04:56 PM
Dragons, Windmills. All Same.
jcstalls's Avatar
United States, IN, Indianapolis
Joined May 2002
3,411 Posts
Greetings,

I use a slowfly 10/4.7 on 8x800 nihms and will almost hover on a fresh charge. Also you may want to make a new set of longer landing gear for clearance.

With elevator/flap mixiing it will ROG off the grass in less than a foot. Cool mod for five bucks.


Jared

http://www.rcgroups.com/forums/showt...5&pagenumber=2
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Old Jan 19, 2003, 09:31 PM
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Pembroke Pines Florida
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What receiver do you use for your cm?
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Old Jan 19, 2003, 10:02 PM
Dragons, Windmills. All Same.
jcstalls's Avatar
United States, IN, Indianapolis
Joined May 2002
3,411 Posts
Greetings,

I used a Electron 6, a little tight, but rock solid.

jared
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