First test run, throttle becomes stuck wide open! Ideas?

[Timbecile]

Hey endless,

Just got my long time project started up again, running 14s lipo through a ku123 controller and bpm2 rear hub, throttle is an after market bought from local scooter shop. I plugged phase wires only and am running sensorless just to start, and plan to attach halls and a kill switch + e brakes soon after adding ca analyst shunt. Was anxious so went On my way with bare minimum...

Of course on first test run the worst scenario occurs and the throttle seems hitchy, then becomes stuck wide open.. I feathered brakes (thankfully hydrolic front/rear) until it cut out power and I yanked battery wire harness off.

I researched and found that if throttle ground wire shorts/disconnects it can become stuck open? Any other ideas what I can look into to troubleshoot or what might cause such a symptom?

I have a ca analyst v3 already and am going to run the shunt and controller through here in near future which may remedy or atleast mitigate future risk but figured I should look into it still. The e brake and a kill switch are urgently being worked out before any future test runs of course.. The hydrolic brakes make e brake compatability a little harder... Can I wire the ebrake switch (the button unscrews from brake lever) to a generic on off switch instead of is this a bad idea?

Thanks in advance!

-Tim

 

[molybdenum]

Sorry to hear about your incident and I am glad you are alright. I have a shutoff button on the handlebars but by the time I actuated it, I could easily be forced into traffic in the event of throttle malfunction. The best solution is a motor shutoff actuated by the brake levers. I have a set of those pushbutton ebrake cut-off levers and they are too flimsy for my liking. Magura makes a hydraulic ebrake compatible cut-off but it is expensive.

I plan on making my own ebrake cutoff from normally open magnetic reed switches and neodymium Magnets. This solution should be completely waterproof and wires are the same as those of the pushbutton solution.

The wires soldered to the magnetic reed switch will be passed through a hole I drill through the brake lever body and to the controller. I am waiting for the parts, which cost me less than $6.00 shipped on ebay. When the magnet approaches the reed switch, it closes the circuit and shuts off the motor.

Others who have discussed this include:

"Using Reed Switches For E-Brakes" rkosiorek https://endless-sphere.com/forums/viewtopic.php?f=16&t=11760
"How and where to mount magnetic reed switch for regen brake?" electrobent http://endless-sphere.com/forums/viewtopic.php?f=2&t=16722
"Reed Switch buggered" Kingfish http://endless-sphere.com/forums/viewtopic.php?f=2&t=18944
"Normally Open Reed Switch as ebrake" Sunder https://endless-sphere.com/forums/viewtopic.php?f=3&t=47423

 

[dogman dan]

One possibility, at least for now, is mount the e brake handle on the bars, so you have something to grab if you get another run away.

And work on that throttle plug, or connections. You may just have a wonky throttle, so another might be a good idea.

 

[Voltron]

Mine happened right in the middle of heavy traffic, jumping to full power and leaving me riding the brakes (no cutoffs) and yanking wires until it stopped. Very alarming! Got to an open area, and started poking the throttle wire along it's length and found the one tiny area that triggered it. Sliced it all open, and sure enough there was a break under the undamaged looking insulation. That made me get serious about an easy to reach on/off switch on the bars....



Re. backwards throttles...had that happen on a repair...tried 3 throttles that all went to full power as it was let off...then finally read a tip about just rotating the magnets, so picked the easiest one to pry them out, worked fine. Apparently older generic bikes ran them the opposite polarity.

 

[d8veh]

The throttle stuck on full throttle because you have the cruise control enabled, which means that if you hold the throttle against the stop for 5 seconds, it stays there until you operate the brake (switch) or blip the throttle. To disable the cruise control for normal throttle operation, remove the connector bridge from the blue wires.