wr250f conversion

dougf

100 W
Joined
Mar 18, 2022
Messages
114
Went for a ride today, triumph throttle feels pretty good. I think id like maybe a touch more response. Very dry and slippery here right now. Bike is maybe a touch too powerful for the conditions. Ride got cut short because i got a puncture and didnt have the tools needed to fix it. I wonder if its worth trying to implement some form of traction control. I have extra IO now, will wire up the front wheel sensor and write some code later.

Doug
 

dougf

100 W
Joined
Mar 18, 2022
Messages
114
It has been a while since we heard anything, any progress? :)
Yeah a little bit of progress. I finished the aluminium dash and mounted it to the bike. I also spun a PCB to go behind the headlight to replace the birds nest of wiring and plugs underneath. Not 100% happy with that part, I think Ill spin that one again with a few tweaks. The dash itself, I think Im going to do one more revision of the pcb, add uart passthrough and put a Bluetooth modem inside it to directly connect to the fardriver phone app without unplugging/replugging. Also completely forgot to add my overcurrent relay which I need for compliance on the road. Basically just an output which will switch if the controller current gets too high. Otherwise I havent been riding the bike much at all. Flat out with work. Probably going to need to pull the battery apart again. Looks like I have a small drain on cell 3, probably from when they got overloaded at the drags. I did capacity cycle tests on them afterwards and they seemed ok but I think sitting in the hot shed over summer has kickstarted some self draining. Very slow but I do wanna fix it. Will just replace all the cells in cell 3.

Hopefully in a few months Im going to start on a new electric project which should be pretty cool. Not a bike though.

Doug
 

j bjork

100 kW
Joined
Aug 31, 2018
Messages
1,719
Location
Linköping, Sweden
Alright interesting, pictures of the progress is always nice 😉
Do you need an extra overcurrent protection, bms and a fuse is not enough?
No more dyno testing? :giggle:

It will be interesting to see what the new project are, some kind of vehicle?
 

dougf

100 W
Joined
Mar 18, 2022
Messages
114
Alright interesting, pictures of the progress is always nice 😉
Do you need an extra overcurrent protection, bms and a fuse is not enough?
No more dyno testing? :giggle:

It will be interesting to see what the new project are, some kind of vehicle?
My BMS doesnt have overcurrent protection, just monitors the cells. For road compliance you need to have a contactor to disconnect the main battery and it must open when the key is turned off. Ive done that bit. ADR also want overcurrent protection. You can use a fuse but your also allowed to just measure the current and open the relay if it exceeds the rated current. Given Im reading current from the controller, not a shunt, I doubt it will protect anything as a short externally from the pack will not register a current. Could probably do it based on voltage sag as well I suppose. Probably all irrelevent as I get the impression if I dot most of the i's the engineer wont mind. A lot of the rules are based around cars. I also need to fit a second 12v battery which can run the lights for 30 min. Ill fit it for engineering then remove it.

Nah, no dyno testing. The bike feels great. Perhaps Ill take it to the drags one day after work before they shut for winter. Im sure Ive reduced the top end power by turning the pha %'s down but its a dirt bike, not a drag bike and it far exceeds my ability to hold on.

Yeah, think Im going to build an electric ultralight aircraft. Still months away. I didnt regret making an electric bike so Im hoping the same will apply to an aircraft.

Doug
 

dougf

100 W
Joined
Mar 18, 2022
Messages
114
Small update. Pulled my battery apart to find the small discharge on cell 2. Turned out to be a water damaged cell in the bottom left corner. I guess water gets trapped there in the battery mount and while sitting on the sidestand never drains. 2 layers of glass isnt water tight. Repaired and this time I build an ABS box to put the cells into. Its a V1 effort, Ill run it a bit and if I like it make a v2 or get one vac formed.
Took the bike to the drags again last night. Got 4 passes in. Fastest was my last pass. I ran a 13.75 at 134kph. 1.99s 60ft, 5.3s to 330ft and 8.28s to the 1/8th at 126kph. I spent most of the evening struggling with wheelies and my fastest pass was when I turned the power down ;). I also may have experienced some MOE errors on one run. They seem to occur at the transition of field weakening. Didnt end up on the tow truck so Ill take it as a win.

Doug
 

j bjork

100 kW
Joined
Aug 31, 2018
Messages
1,719
Location
Linköping, Sweden
"Did multiple 1.9s 60 foots and best time was a 13.6 @ 140kph"
That is what I found from another time before you modified the battery and tuned it on the dyno.
So it seems you did a little better back then, hmm :unsure:

Did you turn down the battery amps to help with the wheelies? (I suppose so as you said power)
Wouldnt it work to just turn down the phase A, if it was wheelies in the start?
 

speedy1984

100 W
Joined
Sep 28, 2018
Messages
204
Do you know what phase amps you are reaching off the start🤔I couldn't get more than 650ish at 380dc with the 1800 108v and the 620ish with the 96-850 model.Ive also gone direct drive with the same motor but decided I'm going 29s11p molicel pack for Mx events and quicker charging.The last piece of the puzzle just turned up🥳 the 3shul cl1000 vesc.I bought a mint 2021 kxf250 roller to speed up the build.
 

dougf

100 W
Joined
Mar 18, 2022
Messages
114
"Did multiple 1.9s 60 foots and best time was a 13.6 @ 140kph"
That is what I found from another time before you modified the battery and tuned it on the dyno.
So it seems you did a little better back then, hmm :unsure:

Did you turn down the battery amps to help with the wheelies? (I suppose so as you said power)
Wouldnt it work to just turn down the phase A, if it was wheelies in the start?
yeal last time i had a smaller rear sprocket, 46 or something, it'll be further back in the thread. I ran my 60t rear this time. I fried the battey when i did that 13.6 and 140kph run. So yeah, with higher gearing its a better drag bike. With the 60t I wasnt any faster short track because I couldnt use full throttle and keep the front down. Seems about 1.9s is the fastest I can go on a standard dirt bike.

i turned down both. Tried 500, 550 and 600A on the battery current and much the same as the dyno, didnt feel that much better.

Second pass I stretched out the field weakening to get some top end, maybe 15% more in most cases but that lead to the front coming up in the run, not off launch. also stuttered a bit so assuming too heavy on the FW.

3rd pass back to my original FW settings and 550A battery, still pulling wheelies. final one I went back to 500A and dropped the max field weakening value from 1800 to 1600. My understanding being that the % are scaled from that number. Still couldnt go all in. but managed a clean run.

Only got 4 runs in due to someone spilling there car guts on the track. It was fun but I wont be going back.

For a dirt bike, not bad. Completely blitzed the interceptor 650 my missus was riding and within half a second of the tiger 800 at the 8th.

Doug
 

dougf

100 W
Joined
Mar 18, 2022
Messages
114
Do you know what phase amps you are reaching off the start🤔I couldn't get more than 650ish at 380dc with the 1800 108v and the 620ish with the 96-850 model.Ive also gone direct drive with the same motor but decided I'm going 29s11p molicel pack for Mx events and quicker charging.The last piece of the puzzle just turned up🥳 the 3shul cl1000 vesc.I bought a mint 2021 kxf250 roller to speed up the build.
no idea, i didnt datalog anything. It was a touch last minute and just wanted to have some fun. Settings were identical to my dyno runs for the most part so looking at those will tell you my pha amps.
 

dougf

100 W
Joined
Mar 18, 2022
Messages
114
Took the bike out today, this time with knobbies. As a spur of the moment thing I had a crack at flipping some of the current limit settings. I maxed all the speed % ratios up to 5500 to 100%, then set 50% and 6000 and 5% for the rest. Then bumped the overall pha limit down to 1000A or double the Batt amps. This felt softer off the line, just a touch, but I didnt get any MOE error stuttering at all and absolutely rips in the top end now. Something about this controller really doesnt like too much pha amps when transitioning into Weak mode. Maybe a firmware bug. I will need to do some actual testing. The %'s have been bothering me all week. Motor is 55kv and about 100VDC so Id expect at least 5krpm without having to start field weakening.

Also rode most of the day with the throttle in sport mode. I like it, but its definitely a bit too nasty at times lurching or blowing the rear wheel out on hills. It feels a bit more natural then linear mode. Did a lot of log hops without issue so the instant response is reasonably good.

Doug
 
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