Recent content by toolman2

Try 22 magnets.

Hey mxlemming, curious about this nice flux path and assuming you mean potential for additional reluctance torque and wider rpm range from field weakening etc. -I've had a look for pics of internals without any luck, have you spotted some ?

Fair enough, the magnet gaps you have are larger than usual but 100% (or near) is not ideal either. Any big increase in magnetic strength will also give that amount lower kv and will likely change the shape of your Bemf and change the motors behaviour/efficiency but unknown if that's for better...

Hey Mihai, nice job on making this motor from scratch. :thumb: Amberwolf is right and I’ve had this issue before with similar motors, it's the tooth flux going through the halls at higher phase currents triggering errors and is nearly guaranteed when heading towards saturation. Your magnet gaps...

That temp difference seems higher than it should be. Easiest way to find out is to ride it for 5 or 10 mins around the 130deg reading and let it rest for about 3 mins watching the two temps, the 130 should drop early on and the 70 would rise initially. The two would have to be within about 10...

Those 12070 motors are pretty good I reckon, optimised for high continuous torque. Folks here didn't like them much years back cos of high idle current, much low inductance counselling was needed.. I have heaps of data on them, and was running 32khz pwm to sort things out, for now here's a vid...

Yea I got you, the 400kv and geared set-up would have 16 times less copper loss. But a couple of things: the 400kv motor in this case would not need 4 times the current, it would actually be the same as the 100kv motor with no gearing. -the motor would make 4 times less torque from the same...

Yea, it is 1:1 for that part also. Ie double the KV is half the Nm per amp. Copper (ir) losses are reduced heaps with gear ratio increase because motor torque is less for the same wheel torque. Doubleing the reduction ratio halves the required motor torque and is four times less copper loss...

Appears to be a pair of two stage reduction gears and motors at the rear just like the single two stage reduction set and single motor the front has, and the above is quite high praise for a drive system using 12 gears in mesh. "multiple stages of loss causing levers as a crotch for a wrong...

That is not correct and this appeared to have been successfully clarified by a number of members over the last page or two. -When phase amps are at their peak, the motor rpm and voltage are going to be at a minimum. At this point your display for battery power consumption is going to reflect...

-The attraction is going to cancel out nicely only when dead centered and that's never quite going to be the case, the force from the side that's a tiny bit closer will quickly dominate and it will get pulled in until contacting at a guess.

Agreed speedmd, they are nice finds.. The first one 20kw 238mm dia is of interest, with the Joby motors now impossible to get and these roughly looking like half the rpm and double the torque and about $1000 on alibaba i reckon you could have a machine just as competitive as the Joby bike using...

Hey EG, nice job on prepping the stator and the rewind. Question though -what brand etc is the red paint you have used there? looks like a good thick coating for short protection. Thanks.

+1 yes, running this motor to 6500rpm unloaded would use 1kw as would producing about 40Nm (that it can do), so loaded to that level is fully maxed out and realistically making about 22kw output and around 90% efficient. -not a bad result for a 4kg motor despite the nay-saying.. -The lams are...