Author Topic: Magic pie V5 almost no torque at low RPM  (Read 1687 times)

Offline Driftworks

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Magic pie V5 almost no torque at low RPM
« on: May 26, 2020, 10:31:44 PM »
Hi All,

Quick introduction, my name is Dave and I’m currently building my second Drifttrike using a 1000W 20inch golden motor hub motor in combination with a Vector V5 1000w internal controller. Although the internal controller has been built into the frame of the trike instead of in the hub motor.

But now I have encountered a problem which I’m wrecking my brain on. The engine responds to the throttle propperly when the wheel is lifted of the floor. As soon as you apply pressure to the wheel, the engine starts shocking. When driving the trike at higher RPM this problem doesn’t exist. I don’t understand why the engine has such bad torque at low RPM, and what changes when it increases. I have used many of these set-ups before on a different project, but never encountered this problem.

Edit: when the wheel is stopped by hand (at full throttle) the LED indicator on the controller blinks 4 times. (Switched controllers and thumb throttle’s and problem stays the same.)

All help is welcome,

Best Regards,
Dave
« Last Edit: May 27, 2020, 01:43:47 PM by Driftworks »

Offline Bikemad

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Re: Magic pie V5 almost no torque at low RPM
« Reply #1 on: May 27, 2020, 01:40:44 PM »
Hi Dave andto the forum,

The Magic Pie 5 controller will only work with a Magic Pie 4 or 5 and will not work with earlier Magic Pies.

I gave up trying to upgrade an early MPIII using a pre-production MP4 vector controller as I could not get the motor to run properly:
Quote from: Bikemad - 1st August 2014
I decided to test the wheel in the bench vice before refitting it to the bike, which turned out to be a wise decision.
I connected the controls and battery and tried the thumb throttle. As I gradually pressed it, the motor suddenly started at full speed and did not alter the speed until the lever was released.
It seems to work just like a simple On/Off switch with no variation in the motor speed whatsoever (either full speed or nothing).
If I pull either of the brake levers and then try to use the throttle it will not run (so the brake switches are both working) but if I pull either of the brake levers while the motor is running it does not cut the motor and does not disengage the cruise control when cruise is activated.
I also discovered that if I open the throttle and then pull a brake lever, I can release the throttle completely and the motor will continue to run at full speed for as long as I keep the brake lever held in. Releasing the brake lever then causes the motor to stop.
If I re-apply the throttle before the wheel has completely stopped it really jerks the motor and a couple of times it has even caused it to cut out completely and would then not restart until I disconnected the battery and reconnected it again.

GM had apparently modified the stator windings and hall sensor positions to suit the sine wave controller, but the changes to the windings meant that the sine wave controllers were not compatible with "non-vector" motors.

The MP5 controller will also work with a Magic Pie Edge or Smart Pie vector if different firmware is installed (but it will not work with an original non-vector Smart Pie).

Unfortunately, the MP5 controller is unlikely to work correctly with motors that were not specifically designed for use with Vector controllers.

However, if I've misinterpreted your description, and you are actually using a 16" MP5 with its original controller mounted externally, the problem you are experiencing must be down to the extended phase wires (or possibly an incorrect hall sensor configuration?).

The 4 blinks indicate that the stall protection function has been activated because the motor has been stalled for too long.

Alan
 

Offline Driftworks

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Re: Magic pie V5 almost no torque at low RPM
« Reply #2 on: May 27, 2020, 02:06:58 PM »
Thank u so much for your detailed awnser! We are having similar problems with the regeneration button like you have described. Like it is a full throttle or off button. However with a different combination  of hall and fase wires it will run “propperly” off the floor. Unfortunatly I don’t know what type of wheel I have and I haven’t quite worked out how to post pictures here. :/

The hub motor came with an internal pcb controller saying MX328 PCB. (Not sine wave)  I have removed this controller and running a Kelly sine wave controller on a similar wheel without any problems. Seeing as I have a whole heap of V5 controllers at work I expected it would be doable to fit it to a same branded wheel. Especially because the power is rated identically. But it sounds like I’m not the first one trying this. 🤣

Offline Bikemad

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Re: Magic pie V5 almost no torque at low RPM
« Reply #3 on: May 27, 2020, 06:25:58 PM »
Unfortunately I don’t know what type of wheel I have and I haven’t quite worked out how to post pictures here. :/

Check out this post regarding posting pictures.

Alan