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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Matt Piatkowski on October 04, 2015, 04:36:32 AM


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Title: Plane for Cobra 2826/10 and /12
Post by: Matt Piatkowski on October 04, 2015, 04:36:32 AM
Hello,
I am sizing the model for these motors: wings span, area, moments, tail configuration etc.
David Felinczak uses 2820 in his Legacy but he wrote that this plane was "heavy at 58.1 oz."

Cobra 2826/10 and/12 are a little more powerful than 2820/12 or/14 so the plane of Legacy size weighting, say, 54 oz. should fly well, I suppose.

As usually, I would be grateful for your suggestions and comments.

Regards,
Matt
 
Title: Re: Plane for Cobra 2826/10 and /12
Post by: Joseph Daly on October 04, 2015, 07:17:27 AM
Matt,
The 28 series cobra are good motor, however they tend to run on the hot side when in a full fuse. I have found that the 35 series run cooler in full fuses and do not weight much more. I have used a 3515 on my rounder, which weights about 55ozs and has no issue pulling that plane and would easily pull a 60 oz plane with no issue. The motor runs a warmer then ambient even on really warm days. They also have 3 large bearing in them. The only draw back is they are wide, other then that it is a really strong motor.

Joe
Title: Re: Plane for Cobra 2826/10 and /12
Post by: Joe Yau on October 18, 2015, 10:18:27 AM
Hi Matt,

On my new Electric Legacy (weights 62.5oz w batt).  It has an E-flite 32 on it, but after about 9 flights, it went bad (had bearing issue then burned up something inside)  so I replaced with a Cobra 2826-12.  using Igor's 11x5 3-blade on it.  The setup with the changes was near 2 oz lighter then the previous with .4oz tail weight removed.  I liked it better as it turns better.  But it got a bit toasty.. had a temp reading of 182F degree :o just after a flight.   so I end up replacing it with another 32.   I would think something like a Vector 40 to maybe an Oriental Plus (600sq in) should be fine with the Cobra 2826-12 :)
Title: Re: Plane for Cobra 2826/10 and /12
Post by: Tim Wescott on October 18, 2015, 11:33:55 AM
We really need more college- and high-school-age people in the group.  I suspect that our knowledge of how to cool motors properly is exceedingly primitive, and a nice thorough study of how to implement good motor cooling in a stunter should make a good senior project for a college kid, or a dynamite science fair project for a high-schooler.

If anyone knows of published results I'd be interested.