20KW 2WD having misfires (but can do a double burnout)

The best solution IMHO is to build the double-hall throttle. It is the natural solution and builds in slightly less power to the front hub.

That would be important! I was thinking of a way to limit the throttle to the front hub at starts anyways. Keep the front wheel from just spinning (also it'd reduce the need for giant torque arms) This would kill two birds with one stone. Probably the smoothest way to do it too. Just wish it worked with a magura.

XLYTE has a two motor controller out. Probably could just reverse engineer the circuit on that to figure it out?
 
JozzTek converts Magura throttles to hall output IIRC. I dont see any reason they could not do two sensors instead of 1 - or you could do it. I like Magura throttles but a physical pot controlling 40KW or 50KW is really dangerous... A hall sensor with a magnet should last forever. Sounds safer to me.

http://www.jozztek.com/shop/en/throttles/23-british-throttle.html

-methods
 
This reminds me of something funny. The Sevcon controller manual calls out an "isolated double sensor throttle" for redundancy in the event some system fails, it only uses the lower value of the two throttle input readings.

We asked them, hey! Where do I find one of these???? They said, "umm... they make one in a foot pedal for fork-lifts... we've never seen any for a motorcycle... :)"
 
Yeah. I defiantly wouldn't want to be in a warehouse the day a hall sensor fails on a fork lift and sends pallets stacked to the roof flying everywhere. Very dangerous. Very big liability.

So when will high powered electric motorcycles get these?

WRT to the hall sensor magura: 130 pounds! SHIT.

JRH said somewhere that magura is either interested or actually producing a hall sensor based throttle in the future. Would be a nice day. Maybe someone can convince them to make one with dual halls to be used with two controllers or as a safety feature?
 
Would another possible solution to the double controller / single throttle problem be to run the hall to a pair of op-amps (or transistor amps) for tuning the gain to each controller, and then the output of those to separate analog-output optocouplers, or isolated instrumentation amplifiers (if such exist for this purpose), and then to each controller?

Yes, it's probably more work than modding a throttle for dual halls, but for those with no mechanical skills at the latter, the electronic splitter might still be within their abilities to wire up.

I guess the key would be to work out the circuit and test it before setting it up on the bike for that power-blasting test ride. ;)
 
liveforphysics said:
This reminds me of something funny. The Sevcon controller manual calls out an "isolated double sensor throttle" for redundancy in the event some system fails, it only uses the lower value of the two throttle input readings.

We asked them, hey! Where do I find one of these???? They said, "umm... they make one in a foot pedal for fork-lifts... we've never seen any for a motorcycle... :)"

This is the dual hall foot throttle they talk about: http://www.evsource.com/tls_throttle.php

You could always have a conventional cable twist throttle operate a modified foot throttle for an excessively complicated system. You gain a hall sensor but add some additional failure points by adding the mechanical cable linkage. :lol:

JozzTek's throttle does look nice & worth considering for a high powered electric motorcycle for sure.
 
That's not a magura we have on site, but a handmade solid aluminium throttle, hence the price. We're currently looking at ways to get this machined in bulk to cut costs. I'm not sure how easy it would be to fit with twin sensors, since we have the sensor fitted to the end of a bolt, so it can be changed without the need to strip the whole thing down.
We also offer a choice of spring strenghts and operating range (1/8 turn as standard). Output is full range, 0.05v-4.95v..
For dual Kelly controllers on one throttle, we just tied gnd from both throttles and used just one controllers 5v supply to power them, this worked out well..

Jozz
 
So last night on my bmx with 24s 2p lipo and X5 and a 24fet running ~180 amps peak (detuned a bit for less waste) I was ripping and hit the railway tracks then my throttle fet funny and my bike slowed down I twisted off then on and it was ok for a bit then nothing again so I let off and wham it went full throttle.... I have ebrakes thank god and used them to keep the controller shut off till I pulled over and found the cheep plastic housing was busted so the magnet was spinning away from the hall in both directions! I carefully road home but man I now understand we need something with a fail safe!
 
Jozzer said:
For dual Kelly controllers on one throttle, we just tied gnd from both throttles and used just one controllers 5v supply to power them, this worked out well..

Jozz

IIRC the Kelly of that power range has optically isolated inputs doesn't it? Even if it doesn't, I think the problem we are seeing with these infineons has to do with the firmware. It is not the best.


Arlo1 said:
So last night on my bmx with 24s 2p lipo and X5 and a 24fet running ~180 amps peak (detuned a bit for less waste) I was ripping and hit the railway tracks then my throttle fet funny and my bike slowed down I twisted off then on and it was ok for a bit then nothing again so I let off and wham it went full throttle.... I have ebrakes thank god and used them to keep the controller shut off till I pulled over and found the cheep plastic housing was busted so the magnet was spinning away from the hall in both directions! I carefully road home but man I now understand we need something with a fail safe!

This happened on my KMX trike. I "pulled up" too hard on the throttle which caused the plastic grip to pop out, release the spring, and then pop back down. The throttle was then free to slide back and forth hammering full throttle. The 20A ebike guys may not understand... but anyone who has built a monster and had it get away from them sure does :shock:

I was once walking my bike through the living room past my mother in law when I accidentally blipped the throttle. It climbed all the way up my front door and bounced the front tire against the ceiling and left a burnout on the floor and door. Freaked her the hell out :p I keep the bike turned off now until I am on top of it :wink:

Another night we were prepping one of Steve's bikes for the TTXGP... We had just finished and the rider was going to test it out. She had NEVER ridden an electric before and she clearly had no idea how hard they kick off the line. (this is a full size race bike with dual Agni and 80Ah Lipo, not a bicycle) The controller was on and everything was ready to go but due to a bug in the Kelly firmware it was locked up. Ok - that was not such a big problem... the problem was that she had the bike pointed at a group of us, she was sitting all the way back on the seat, back straight, and she was rolling the throttle all the way up and down, back and forth saying "it doesn't work". OMG - I was waiting for that bike to explode out from underneath her... The Kelly has a "high pedal lockout" but that only applies on powerup. If the problem had been a loose connection or something like that and the controller had kicked on while at full throttle. Pfffftttt.... what a mess.


-methods
 
methods said:
The 20A ebike guys may not understand...
methods said:
I was once walking my bike through the living room past my mother in law when I accidentally blipped the throttle.
Well I managed to make a damage with a lot less than 20A. I've just connected the battery, and blipped the throttle ever so gently to see did it power up, but my hand was wet and bike managed to run away from me and go clean through a bathroom window (which just came from a glass shop) which happend to be propped up the wall 5 feet in front of the bike :D.
 
Oh yes, about your bike. I've just seen video on second page. Holy smokes, that thing accelerates like it's being shot out of a slingshot. :shock:
 
I had exactly the same plastic throttle failure once a few years back, also on a KMX, though fortionatly only with about 5kw of power. I wouldn't consider using one on a motorcycle except in emergency.

This much power is really bordering on needing a contactor and easily reachable kill switch tbh, however safe you make the throttle, one short in the right place in your throttle cable wiring and your controller will see WOT. E-brake is the next best thing
 
liveforphysics said:
The Sevcon controller manual calls out an "isolated double sensor throttle" for redundancy in the event some system fails, it only uses the lower value of the two throttle input readings.

The best dual sensor throttles have the two sensors outputting differential type signals... one goes up as the other goes down. If the two values do not agree mathematically you know there is a fault. Having both sensor signals move in the same direction can mask shorted wiring faults, etc. And for the real paranoid, you want the two signals to be generated by different technologies (like a pot and hall sensor).
 
Rassy said:
3. All three throttle wires must be paralleled together.

Is this method working well? Any updates? I thought i saw someone in another thread said that this method will do more harm than good. :confused:
 
I just saw your question in this thread today warren, but the answer is that I moved away from the house on the steep hill seven years ago and have not used any multiple motor systems since then. I was told repeatedly by "experts" that the full throttle parallel method that I used could result in problems, but I never experienced any problems.
 
So I've clicked on this topic a few times and it seems like all of the videos are no longer here. I'm really curious because of peoples comments on how fast it is if you can upload a video again because I would love to see it
 
damn it, i was being an optimist since it sounded so cool. the pessimist in me should remember what the video quality was like a decade ago though and say it probably was a thumbnail that looked like a potato made of legos shooting fire since my iphone uses 35mb in like a second of video nowadays
 
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