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Dec 27, 2003, 09:06 PM
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larger homemade brushless

I originally posted about this motor on pages 36, 40, and 41 of the original homemade brushless thread. Since I have the motor completed and running, I thought it was better placed in Power Systems, since it is not a micro. It came from a 60M tape drive. Weight ready to go in a plane is a piggish 110g or so, but it is a solid piece of work. Steel bell, ball bearings, 23T of #22 wire, Nippy aluminum motor mount, MPJ 4mm prop adapter, 36 N45s arranged NNN SSS NNN, etc. It is about the same size as a PJS 800.

The photos below show my test setup. You can see the Phoenix 25 just below the motor, attached to and insulated from the vise head by double-sided rubber tape. I tried APC 8x6, 9x6, and 10x7 SF props, all from a brand new, freshly charged 8x1000 NiMH. The 8x6 only drew 2A, and even the 10x7 only drew about 5A and spun around 4000 rpm. I have a pack of well broken in 7x600AEs on charge now, but I'm afraid I'm going to have to invest more $$$ to get the performance I want. This will go in my Mini Telemaster (under construction), and I want to get 10-15A, preferably with only an 8" or 9" prop. More to come.

Tony Turley
Last edited by t-turley; Jan 04, 2004 at 01:25 PM.
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Dec 27, 2003, 09:12 PM
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A little better pic:
Dec 27, 2003, 09:19 PM
-plancks only-
Franck's Avatar

Good to see that things run well.

You might want to use

for some rough calculation on performance you might use the folowing link. Havent really used it yet. (this link is for GWS props, i had the APC version somewhere).
Dec 27, 2003, 10:20 PM
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Are you going to reduce the amount of turns to get the higher amp draw you want allong with going 3s li/po?Matt
Dec 27, 2003, 11:33 PM
Registered User
Thanks for the link, Franck. Matt, I'm not planning to rewind the motor until I've done some more testing. I ran it from the 7x600AE tonight, and fresh off the charger, I got 4200 rpm and about 6A. Looking a little more promising. I'd love to go with 3S2P 1500 lipo, but the $100 US price tag is a little steep. The lipos are great for really small planes, but when you start to look at larger planes - even sp. 400 size - the price escalates rapidly.

Tony Turley
Last edited by t-turley; Jan 04, 2004 at 01:26 PM.
Dec 28, 2003, 01:25 AM
Registered User
Your right,sure hope li/pos come down soon.I just purchased irate 2600s at 10C for my wattage mirage for 22.50 each and am going 3s1p.I guess thats about 70.00 and the pack is hard pressed to fit in many plane fuses but,fits great in my migage.Can't waite to torture the s400 motor for 10+minutes at full throttle. Matt
Jan 04, 2004, 01:30 PM
Registered User
After much testing of props, I've decided the most cost-effective method of increasing performance is to rewind the motor. I've ordered a spool of #20, which should get me down around 15T. The other avenues of performance gain were expensive in either $$$ (lipoly) or weight (increasing to 9-10 cells). The Mini Telemaster was designed for 7-8 cells, and I don't want to end up with a big increase in weight.

Tony Turley
Jan 04, 2004, 02:23 PM
Registered User
I've herd that using 2 strands of smaller wire works well and maybe even better.Ever tryed it insread of using a single larger wire? Matt
Jan 04, 2004, 02:35 PM
Registered User
No Matt, I haven't tried that with this one. I guess I could explore that option, as well.

Jan 04, 2004, 02:40 PM
Registered User
Ya,It sounds good but,not very easy to know how many turns of how big of wire,might be easier to just weight and get the stuff you know will be what you want.Matt
Jan 04, 2004, 02:44 PM
homo ludens modellisticus
Ron van Sommeren's Avatar
Experiment to find out the number turns you, than use the thickest possible wire or several in parallel. The more copper, the better.

Groeten Ron

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