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Dec 29, 2017, 06:56 PM
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BeechSkipperDude's Avatar

Next project - Sig Kobra

Posting here because I want a bit of advice.

This is going to be my next project and I'm going to do some electric retracts and convert to Brushless.

Only problem I'm finding is that many of the easy to pinpoint options like the E-Flite power 25 or 32 or the turnigy g25/32 all have super low KV ratings which allow them to swing huge props.. I don't want that.

Any higher kv suggestions that could run 4-6 cells, swing a 9" prop or so and make this bird set records?

Heck, we could even have a competition. I'll challenge someone to the fastest brushless kobra build 😜.
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Dec 29, 2017, 07:55 PM
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scirocco's Avatar
Just add a cell or 2. There's no need to limit yourself to the recommended voltage for the motors as long as you keep total power within reasonable limits - which you can manage by adding voltage while reducing diameter. For smallish motors like these, rpm (other than prop max) shouldn't be an issue.

Keep in mind both Eflite and Hobby King have high Kv versions of the Power 25 (1250 rpm/V) for EF-1, but these are pretty much maxed out by 4S and an 8x8.

I had a lot of fun with a Sundowner 32 on 5S, 810 rpm/V and 10x10 prop.

If you advise your power expectations and any limitations, eg will not use more than 4S, i'm sure you'll get plenty of ideas
Dec 29, 2017, 08:26 PM
I just want to go fly!
walter3rd's Avatar
Good luck. I built the king kobra with retracts and electric motor and itís a fun plane. Looks fantastic with gear up. Have fun.
Jan 21, 2018, 11:02 AM
Onward and Upward
CatManDu's Avatar
Good looking plane, Walt.
Jan 21, 2018, 04:57 PM
Registered User
Model Motors (Same guys that make AXi motors) make some inrunners that would work great. The are very efficient and sturdy as well. Check their motor spec charts to find the one that will work best. I'm guessing one of their long can 22mm dia series......
Apr 02, 2018, 08:35 AM
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BeechSkipperDude's Avatar
Well. Picked up a sealed kit from a member here in the classifieds. Just gonna finish up some other projects and get to working on this ship soon!
Apr 02, 2018, 03:08 PM
I just want to go fly!
walter3rd's Avatar
Nice score. I like sig kits.
Apr 08, 2018, 11:11 AM
Registered User
I am using a Rimfire 60 on a 13x8 two blade with my Kaos.
Flys great , sounds great and i get 6 mins of high, mid and low speed options.
I even have the gas flying guys paying attention @

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