View Full Version : Brushless motor wire diameter.

02-19-2007, 02:30 PM
Having purchased a brushless motor kit of parts I happen to measure the diameter of the stator wire supplied. The kit states 23AWG wire but on measuring with a vernier micrometer shows it to be 22AWG.
Not a big increase, I hope, for my 12amp speed controller and 3 Li-Po's to handle.
Are there any tables, charts or calculations to show how much current will flow for different AWG sizes using 2 or 3 Li-Po's.

02-19-2007, 03:15 PM
Have you allowed for the insulation on the wire ? I imagine 23AWG should be the size of the copper not the overall size with insulation.


02-19-2007, 04:02 PM
Good point !
0.65mm with insulating varnish and 0.63mm after removal.
Checked at three separate points every 500mm along the wire and used the ratchet each time to obtain equal pressure readings.
Still quite a distance from 23AWG(0.57mm) with or without insulation.

02-19-2007, 04:26 PM
Dave, Welcome to Wattflyer

Please see the following thread. It may help.


Sorry I didn't read your post very close. The wire will handle more current but shouldn't generate more. Does that make sense? Its the number of windings that will be the biggest factor in determining the amount of current produced. Current is induced in a wire as it cuts through a magnetic field. The more wires (determined by #windings) that cut through the more current. The reverse is true when you are trying to use the windings to gererate the magnetic field.

02-19-2007, 05:37 PM
Yep you need to determine the amount of winds you need to achieve your desired kV first, and then pick the thickest wire gauge that will allow you to fit that many winds.

02-19-2007, 06:09 PM
Yep you need to determine the amount of winds you need to achieve your desired kV first, and then pick the thickest wire gauge that will allow you to fit that many winds.Or, if the wire would get too thick, wire 2-5 wires in parallel. Parallel winds count as a single wind.

Excellent motor building articles by Brian Mulder, a must read, will prevent you from asking a lot of questions :-)
-> Articles by SouthEasterners.
-> Electric Motors - part 1-5

Do-it-yourself motor homepages, manuals/tutorials, checks and tests in this motor builders tips and tricks thread. The checks and tests may save you from frying your controller or motor. Thread is active, bookmark it for future reference and subscribe to it:
http://www.rcgroups.com/forums/showthread.php?t=240993 (sticky thread, at top of subforum)

Vriendelijke groeten ;) Ron
• diy motor building tips & tricks (http://www.rcgroups.com/forums/showthread.php?t=240993)
• diy brushless motor discussion group (http://www.yahoogroups.com/group/lrk-torquemax)
• Drive Calculator (http://www.yahoogroups.com/group/D-calc/) download & discussion group
• int. E fly-in & diy outrunner meet (http://home.hetnet.nl/%7Eronvans/), Aug.26 2007, Nijmegen, the Netherlands

02-20-2007, 03:31 PM
Thanks to all for your comments and websites recommended, there's more than enough info' to read thro'.
I would like a Kv of around 750 - 800 as my intention is to replace the old Graupner brushed 400 and G/B I have installed in a small 36" span glider. It's looking like 10turns on each segment of the stator will do nicely, along with the ND50 magnets recommended - boy are they strong.
Right now my objective is to wind the wire very neatly on all segments and by next week it should be completed.

02-21-2007, 02:16 PM

keep us posted.