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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Chris_Burgess on June 29, 2012, 03:45:59 PM

Title: Motor Size?
Post by: Chris_Burgess on June 29, 2012, 03:45:59 PM
I'm looking at putting together a 35-40 size stunt ship, I'm thinking an e-flite power 25 might be over-kill, would a power 15 give me enough oomph to tote it around, think the size of the silencer, seeing as I'm using that wing...
Title: Re: Motor Size?
Post by: Tim Wescott on June 29, 2012, 05:52:44 PM
Mine says it's good for up to 425 watts.  Divide that by 11 to get the plane weight in ounces.

You could probably push things a bit higher because (weight)*(11 W/oz) is for peak power and the average is a bit less.

But I think I'd try to keep the weight down to 39 oz or less.  If you know you'll have more weight -- get a bigger motor.
Title: Re: Motor Size?
Post by: Chris_Burgess on June 30, 2012, 09:54:25 AM
Thanks for the Advice!
Title: Re: Motor Size?
Post by: Jeff Traxler on June 30, 2012, 11:42:24 AM
Chris,
        I have had great success with the cheaper 3542-1100KV motors.A 4s 3000MaH pack and I simple FM-0c timer from Will Hubin and a Hobby King 40A ESC.I have had 100's of flights with this setup and only 2 glitches/.The first was a low bottom/CRASH on an outside square(pilot error) and when I put a discharged battery in with the hot ones which was also an Einstein manuver.I did get some great taxi experience LL~ LL~ LL~ LL~ LL~
 If you don't want to spend an arm/leg to try E this might be a way to go.
                                                                                                   Jeff "T-Bone" Traxler
Title: Re: Motor Size?
Post by: John Cralley on June 30, 2012, 08:32:22 PM
Jeff,

Bob Hunt had a simple solution to keeping batteries straight - charged vs discharged. If you put a rubber band on your battery when you charge it and remove it when you use it to fly, you will save on taxi time.  y1
Title: Re: Motor Size?
Post by: Leo Mehl on July 15, 2012, 09:21:01 AM
I flew my Nobler with an e-flight 10 motoer with a cut down apc 12X6  prop and the lap times were perfec5t for me. I aplso flew it with a e-flight 15 which is a little better as fare as power goes for that size plane. I am Now dezigning a new plane for the 15 that will have a 500 sq, inch wing with a top load battery compartment for a 3300 3 cell battery, I am sure this will be a good flying plane when finished.
Title: Re: Motor Size?
Post by: Dennis Toth on July 15, 2012, 10:10:34 AM
Chis,
The one thing about electric is that putting a bigger motor does not hurt things, it will run the same rpm that is set in the ESC regardless of the prop (within reason) as it does without  a prop. So the choice becomes prop size you want to run and balance of the plane. If you need more nose weight put in the bigger motor and let it have the reserve power for maybe using a wider blade prop.

With the top loader make sure the motor mount wall is securely attached to the fuse sides. I use small countersunk wood screws through the doubler into the mount wall. Make sure the mount wall is substantial, don't use 1/8" lite ply unless you are going to use an external support bearing. I have been using 3/16 ply on all my ships (35 to 50 size ships) and have not had any mount failures.

Best,         DennisT