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Old 03-15-2010, 03:01 PM
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Default ESC Timing and High kV

I'm not sure if this is the right forum but I thought I'd give it a shot...

I purchased a GP SS 25A Brushless ESC a couple of years ago to go along with a (now discontinued) Rimfire 2826-1600 kV motor. When I eventually put the two together some time later and fed the ESC with a 3s 20C lipo, the motor got extremely hot almost instantly when spun up. It sounded fine but I could smell the smoke coming on. Basically, it smelled like motor was about to fuse together. Realizing this in time, I quickly shut it down. I wasn't sure if the ESC or the motor was the problem so I took a CC TB 54A ESC and tried things again after cooling. With the CC ESC, the thing ran like butter - smooth and consistent. I figured the SS ESC was defective.

I put the two aside for another year and pulled them out again a few days ago with a new project in mind for them. I though I'd tempt fate and try the Electrifly combo together again and to my surprise there was no heating issue. I tested it with several different lipos to exclude those as a source of the problem (although I doubted it). While the motor no longer heats up with the SS ESC, as soon as I pass about 1/3 throttle a nasty grinding sound begins. I tried the ESC on a larger Rimfire 1500 kV (~600W) motor with the same 3s pack and the same sort of problem arises - the motor grinds past a certain throttle position. Again with the CC ESC all is smooth on both motors.

Next, I thought I'd try a different brand of motors - Turnigy's. Both about 700W motors, one ~1300 kV, the other 750 kV. With the 3s packs and the SS ESC, the 750 kV works smoothly although underpowered (as expected). The 1300 kV work much better than the Rimfire 1500 kV but grinds just a bit but nothing that I'd say, there's a problem here. I ran both Turnigy's for a while and they were both cool to the touch after a while of running at 3/4 throttle. I didn't try the CC ESC on the Turnigy's as I'm trying to figure out the problem with this SS ESC.

So, with that rather lengthy preamble, is it possible that the timing on this 25A SS ESC is not right when it comes to running high kV motors? How or what can be done given that this ESC is practically specifically designed to work with the little 1600 kV Rimfire that I bought it with? Can the timing be changed or does it need to be serviced...?

Thanks in advance for any suggestions.