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tiloldar
06-20-2009, 07:27 PM
Please don't laugh at me for the dumb question. I probably already
know the answer; but I wanted to make sure.
The stator teeth from the diy brushless suppliers are coming with
the enamel covering the edge of the teeth. Will this have a big
impact on the performance of these motors and should I sand off
the coating to clean up the teeth?
Also, some of my stator teeth are not clean from laying around
for awhile. Should I sand them with fine sandpaper or emery cloth
to shine them up?
Thanks for the advice,
Tilo

ron_van_sommeren
06-21-2009, 10:19 PM
The enamel insulation is there to prevent the (insulated!) winding wires against shorting/knicking against the otherwise sharp edges. No effect on performance, don't worry.
Rust is no problem, just extra insulation, you don't have to shine them up. By sanding/filing the rust you may create burs on the laminations, those can create electric contacts between the otherwise insulated laminations -> higher eddy currents -> higher losses. Read posts #4 and #5 in this thread, about laminations, insulation and eddy currents:
http://www.rcgroups.com/forums/showthread.php?t=1067192First

If you have not done so yet, read this rewinding introduction
www.gobrushless.com (http://www.gobrushless.com)
-> knowledge base
-> basic overview (1-5)

More stator insulation methods in item #16 to #25 of first post in this "Tips and tricks, checks and tests, may keep you from frying yer ESC and/our controller" thread:
http://www.rcgroups.com/forums/showthread.php?t=240993

All manufacturers use enamel, usually green or blue, e.g. Kontronik:
translate.google.com...www.powercroco.de (http://translate.google.com/translate?u=http%3A%2F%2Fwww.powercroco.de%2F&langpair=de%7Cen&hl=en&ie=UTF-8)
-> Site Map
-> repairs, tuning
-> power Pyro Kontronik

http://www.powercroco.de/powerpyro/10.jpg

tiloldar
07-04-2009, 07:14 AM
Thanks much Ron,
I feel honored it is you answering me.
I wasn't worried so much about the
extra insulation, just the rust on the
"head" of the stator teeth. It is easier
to understand thinking magnetic.
I guess it was just the "electrician" in me that
worried about the rust. I am too used
to wanting everything clean and shiny :o.