Recent content by MCF

In case anyone runs into a similar problem. Apparently the MXUS xf19r at 72v does not play nice with a squarewave KT controller (presumably the RPM is higher than it can keep up with as its a 1.6:1 geared motor). Replaced with a sinewave controller and everything is working.

Thank you.

Trying to test motor coils, I know they're not supposed to short to axle/chassis. But is there supposed to be continuity say testing between blue and green phase wires on motor side?

:bigthumb: That's the thing it worked fine with the 52v kt sine wave controller. Now with the 72v square wave controller it's being a pain. Is your kt controller sine wave? I wonder if a sine wave version can handle the higher rpms better.

Went back through and checked all the wiring. Borrowed a generic 72v controller the kind with the 3 speed switch and no display and self learning. Worked fine on speed 1 and 2, but on speed 3 it would break up. Since my geared hub has 5.8:1 ratio is it possible for the erpm to be to high...

Went through all combos again, wrote down all possibilities and checked them off as I went. Ended up with 3 forward and 3 reverse, that didn't set errors or sound like a coffee grinder. Controller and motor are both cool. short video of what its doing unloaded at full throttle/speed...

MOSFETs test fine 10kohms from phase wires to ground OL (out of limits/inifinity) from phase wires to power I think the resistance I am feeling is the clutch for the gears.

I did all 36 combinations got 3 that would go forward smoothly, oddly those 3 all pulled the same wattage and sounded the same. Thank you for this link. I stumbled on it when I first started with this problem and then couldn't find it again. this section from that page: "Note: If...

I just went out and tried all possible phase combinations. Only one combo works, issue still exists. It was a great suggestion, thank you. On a side note, with the battery voltage down to 64v it runs well. Will top out at 41mph and is giving me 2000w (per display) so aprox 32 amps. Charged...

I've gone through the parameters a few times. They all look good. (Same as on previous controller, that worked well) Didn't think about resistance in the wiring to the controller. It's 10 gauge from battery to controller. Will check it out tomorrow, thanks for the input.

Hi everyone, I'm having trouble diagnosing issues on my current upgrade. About the bike: motor is a MXUS XF19r was origionally running it on a KT 12 mosfet 40a controller with a 15s battery for approx a year. Bike used for commuting, pulling trailer with pretty heavy loads, and errands. All...