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Old Nov 27, 2007, 12:25 AM
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Dave North
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USA, CA, San Jose
Joined Apr 2004
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hexTronik DT750 Brushless Outrunner 750kv

Okay, I laid out the big bucks and got one of these new big motors from HobbyCity DoNotSayUnitedHobbiesOrGetSuedByJerkCo. You can see their specs at:

http://www.hobbycity.com/hobbycity/s...idProduct=6247

First, I'll toss out some numbers at you. The Kv computed out to more like 800 than the 750 indicated, but this should not be a surprise. The stator was probably supposed to be wound with 18 Turns of 8-strand 34swg wire, and indeed five of the teeth were. However, those other three proved a little challenging for our overworked winding slave, so they settled for 17, 16 and in a fit of pique, a mere 15 turns on one tooth. So I got a little bit "hotter" wind than intended.

Nevertheless, here are the stock numbers with Rod Badcocks calculator giving the thrust and percentage figures. The thrust is very close to what I observed on the stand, so I'll concur with those numbers.

Hex DT750 Stock 8strand 34swg ~18 Turn

GWS 10x4.7sf TP 1320 3S:
7210 rpm @ 10.76v/13.96a 962 grams 34 oz/thrust 83.9% Efficient
APC 11x4.7sf TP 1320 3S:
6446 rpm @ 10.5v/17.3a 1218 grams 43 oz/thrust 81.6% Efficient

Make of that what you will, it's quite good compared to almost everything else I've tested with those props, but weighs about .7oz more, so that should be no big surprise. What is surprising is it does so well with random winding. Makes me curious what it will do if wound somewhat properly.
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