KTM 200 exc goes electric

I made some changes last week before the ride on the weekend:

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A new bracket for the regen button, now it is held by hose clamps.
It is a little bulkier, but it dosent seem to be a problem.

I also tried my domino throttle instead of a Chinese hall throttle:

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I soldered in resistors on the positive and negative to be able to have some safety from especially a problem on the negative connection. So it wont go full throttle if there is a fault.. I think it is a little more linear, or maybe it is just that I have gotten more used to it.

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I used 330ohm, but higher would maybe have been better.

I also just ordered another charger. You shouldn't drink beer and browse aliexpress or ebay :roll:
Mine hasn't been totally reliable, it sometimes resets and go to a lower voltage. Never higher so far..
I dont really need to charge at 50A anyway, at lest not so far. So I ordered one of those modified 0-120V 0-25A.
I hope it works fine. It seems like they take out one of the big caps to get room for the pots to set V and A, I hope that wont be a problem.. If I want a fast charge I still have the one I built.
 
thoroughbred said:
Hi can you explain how the resistors work to prevent a runaway throttle situation?

The domino throttle is a potentiometer, I am not sure what its resistance is but something like 5k ohm.
When you connect ground to one of the base resistor connections (or what it is called in English) and 5v to the other, what you will get on the signal wire (wiper?) is 0 with released throttle and 5v at full throttle.

The problem with this is that if you loose the 5v connection you will get 0v no matter the position of the throttle, not a big problem.
But if you loose the ground connection you will get 5v, and that is full throttle..

What the resistors do is add an offset. Now 0 throttle is maybe 0,3v, and full throttle maybe 4,7v. I cant give a very good explanation in English, but you add resistance to the throttle that you cant access with the output (wiper?) on the potentiometer.

If you loose ground or 5v connection you will still get 0 or 5v from the throttle no matter the position, but now you can setup 0 or 5v as faulty outputs. So the controller goes to protection shut down instead of full throttle.
 
j bjork said:
My charger has been working fine, so I went on and changed controller to the votol em 150sp I bought together with the motor.
The specifications are not very impressing with 380pA and 120bA, but luckily it is unlocked :wink:

I thought it wouldn't deliver good pA, but according to another members measurements it does.
And it sure feels like it does. I have it set up for 500pA and 300bA, just like I had on the nuc.

In sport mode this sure has a lot snappier throttle response, and better power at low rpm.
Just what I needed, the peak power has never been a problem so far :D

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I made the brackets for the nucular 24fet. But when I understood that this controller may be interesting too, I modified them so both should fit. But it is not a very good fit on this controller. I would like to mount it further out, more in line with the seat. But that would mean cutting the old one off, and weld on a new one..
I don't feel like stripping the bike, paint and all that at the moment :(

Some other things to play with:

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An 80 tooth rear and some 11 tooth front sprockets.
The 10 tooth I have now is pretty much worn down, and has a lot of play on the shaft.
I think these will be a tight fit, but were not available in 10 tooth.

I think it would be good to go bigger than 80 tooth rear for the gearing, but it is so damn big :confused:
A problem is that it is steel.. It will probably last forever, but I think it weighs 4kg..
It will need some serious lightening.

The bike worked very good today, but I crashed a few times.
At one time I broke my light switch:

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I used the flasher switch as a 3 speed switch, with reverse, mid (or high, a bit confusing in the program) and sport.

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It felt kind of broken, but stayed in sport so I could continue. I think I will just get rid of it, I don't really need high/low beam atm. anyway. I only use sport on the track, but I like to have reverse.

On the picture is also my button for regen, no variable regen on this controller unfortunately. But it worked pretty good so far anyway. It locks the wheel on loose ground, but I usually did that with the variable regen too. It just skids a little on big rocks, so it seems like I found a decent all-round setting.
What I miss the most from the nuc is the very nice display.'

Oh, and another thing. A guy at the track had a ktm freeride, and he let me test it. I was too tired atm to take it to the track, so I just took a quick spin on a dirt road.
And I can say that my bike sure felt more powerful than it, and definitely snappier :D
It was a bit to short test to say to much for sure, but that was the feeling I got anyway.
what an amazing build!
this post got me curious though.. are you saying that you can unlock a votol 150sp and then set it to 500Pa and 300Ba and it will not burn out?

also very impressive how you can get so much power from a 3000W motor. the parker hannifan on my scooter is 3900 Watts and it already gets hot when configures according to specs. when i increase Pa or Ba it gets waaayyy to hot. sounds like a plan to swap it for one of these motors.
 
Thanks :)

The controller is unlocked, so you can set it how you want.
The phase amps is not very different from the default setting.
It is supposed to be max 380A in these newer controllers, but it seems like they are set up at 470A like the older ones.
So my settings for 500A is not very different.
The default setting is max 120 battery amps though, and something like 140 or 150 in sport mode.
So there are 300 a little more :wink:
 
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Back from today's ride, before wash.
This time it wasent trouble free though:

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I did plan for problems like this though, so I could bypass the bms and continue.
The display refused to show anything useful, only some Chinese that probably said there is a problem with the bms..
I could look at the app in the phone and at least see the voltages between laps, the charge left didn't show anything useful when the bms couldn't measure the used Ah.

I wasent expecting the bms to die like this though, it seems to work fine for everybody else.
I haven't taken a look at it yet, but I guess there is a blown mosfet. I hope things hasent got too damaged..
 
I took it apart to get a closer look at what is going on.

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It looks ok at first glance, but when I measure the discharge fets are shorted.
It looks like all of them are driven from the same source, with just an individual resistor to each mosfet.
I measured to each mosfet, all of them seems ok :)

When I took a closer look I think I see the broken one:

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The solder on the middle one in the picture seems to have melted.

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Both charge and discharge mosfets are the same.
What I would like to do is unsolder all of them, solder on a 1mm copper plate on the board and use that to get P-.
Then solder back 12 discharge mosfets and maybe 6-10 charge mosfets on the copper plate. Then the charge mosfets will only be for charging, all discharging will only be trough the discharge mosfets.

But I am not sure if I can do that without damaging the mosfets?
Would it work to just hold a hot soldering iron to the metal part of the mosfets that sticks out, and lift off the mosfet with pliers when the solder melts?
 
I have similar looking ant bms that just one time when I installed my battery back after some tire work gave the discharge mosfet abnormality error. I pulled one leg up from every mosfet and found the shorted one. Really strange way to go imo since it didn't faill under any load.. Anyway since I didn't have replacement or hot air station I just left the leg up at that mosfet. Now my 5 replace mosfets have arived and what should be "cheap but ok" hot air station. It has been so nice weather to ride and do other things that I have not tried to replace the mosfet yet tho..

I would not try with just soldering iron to get the mosfets off but maybe it can be done without damage :roll:
 
Alright, I gave it a try with a 100w soldering iron with a tip that would fit between the mosfets.
I have one with a bigger tip, but that hit the chisel on the mosfets before touching the metal.

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A picture to get a feel for the size I used.

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And it worked really well, it was easier than I expected :)

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I will run my copper plate out in this direction. I need it to clear those connections, but still leave room for all the mosfets.

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This is how it turned out. The hardest part was to keep the mosfets from moving around when soldering.
Especially not to move the first row when soldering the second row.
I went for 6 charge mosfets, it should be plenty for max 50A charging.
I didnt expect 1mm to make a lot of difference to the leg length, but it did. I was able to bend them to touch the bord at least, then I added extra solder to the legs.

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In the box. With the big wires in the "right" direction I could shorten the discharge (now P-) wire a little.

I do worry a little that there might be uneven load on the mosfets now, when I have both wires in the same direction.
Before, with the B- in one end of the copper plate, and C- at the other end of the other copper plate the resistance of the copper plates would even out.
Now it increases in both plates the further it gets from the wires.
I have no idea if it is a big problem, or a non issue..
 
It has worked fine now, except that I have cutouts now an then.
When it happens I have to stop to make the controller work again.
I usually just use the regen brake for the rear wheel, that can get interesting when it stops working when I have the cutouts..

However, last time the second button broke. This was the waterproof one..

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For now I just disable it, and try to get used to the normal brake instead.

I got the charger I ordered some time ago today:

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At first it seemed fine. The fan was pulsing a little, but not a big problem.
But then it started..
A problem I have with the charger I built is that before I reach about 80v one of the psu:s goes a bit low in voltage.
Then the fan goes full speed, it is noisy and really annoying to hear.
Luckily it is not for very long.

On this one the fan goes full speed WHEN I hit 80v. Then it stays at full speed :roll:
It is almost unbearable. I dont think I will be able to use this charger as it is.
 
Finally got some time to work on the sprockets:

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11 tooth JT sprocket in place. I heated it to maybe 100 degrees c, then I could gently tap it in place.
No play between sprocket and shaft now :wink:
Hopefully it will last longer then the chinese ones too, I have already worn out 2 of them.

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A little modification to the swing, I couldn't use the full adjustment range without cutting off the inner bracket for the chain guide.
At least with the 90 tooth sprocket, that is why I got a 86 tooth too.. But that felt like to much of a compromise, I don't want to gear up. I tried to avoid welding the swing arm, because I didn't want to weaken it. Alu get softer after welding. But it seems really strong where I welded, so I don't think it is a problem at all.

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I also made an adapter for the front chain guide, the chain didn't get much guidance on it as it was.

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This is how it looks now, I thought the 70 tooth sprocket I had first was kind of big.
Then I got a 80 toot sprocket, I thought that was BIG.
Now I have a 90 tooth sprocket.. It is really big!
 
That 90 tooth sprocket is massive dude. Should give you insane torque, and hill climbing abilities.
 
I changed front gear from 10 to 11 tooth at the same time, actually it is because of that I changed the rear sprocket.
The change in gearing is not much, I went from 8:1 to 8,18:1.

I wanted to change front sprocket because the chinese ones have play on the shaft.
Some people have broken the splines, and I found these JT sprockets that have a very tight fit on the shaft.
But they are not available in smaller than 11 tooth.

It would be interesting to try 9:1,I think it would be too low and loose power to early in the speed range. But I am not sure..
When I went from 7:1 to 8:1 it sure made a lot of difference to the low end torque, and I didn't loose top end.(at the speeds I am using on the tracks) But I think it is close, at least when the voltage is getting low.
 
It was very muddy on the last ride:

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I had a little problem with the new setup, the rear sprocket seemed to get covered in mud from time to time..
That led to that the chain got tight so it made noise, that probably was not very good for the motor shaft :?

It was a little on the tight side to start with, so hopefully it will be less of a problem next time.
The chain guide also got a little knocked out of position, so it was pressed against the chain where the chain goes on to the rear sprocket.

But it was a little extreme this time with mud and some pretty deep grooves in the tracks at some places.
 
Thanks, on the last page there are mostly some small adjustments. The real building is on the earlier pages :wink:

Not much new to report, but I have changed rear wheel bearings:

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No pictures of the actual change, but is rather basic.
I noticed they were in a bad shape when I changed sprockets.

I am chasing the cut out problem now, from time to time the controller just cuts out.
I have to stop for it to start working again, but I have learned to just lock the rear wheel (and motor) when it happens.
Still annoying, and I cant rely on the regen brake. When it happens the regen stops working..
I like the regen better than the normal rear brake, because it is responsive and direct.
Not like the nuculars regen, where I can regulate exactly how much brake I want. But still better than the normal rear brake.
The normal brake depends so much on how much dirt and water there are on the disc.

The strand thing is that I have been able to log, and it seems like there are no fault codes when it happens.
 
Excellent progress bjork. When will you take some videos of the bike in action? We're dying to see it!

Cheers
Tyler

 
Thanks, nice to know there are interest :)

I'm not very good at that computer stuff, I need to edit the film somehow I guess. Then put it somewhere and link here I suppose..
If I make a film, I am pretty sure it wont be one of those nice ones with speed and power. Maybe music and a steady camera.
It would probably just be a bumpy one, where you can barely see what is going on :wink:

At the moment I'm trying to figure out the cutouts I have from time to time. But I will try to make some kind of film later.
 
How is the front sprocket and motor axle holding up? Still tight afer some abuse? I ended up with a 11T JT sprocket and bigger rear sprocket myself on the ATV. The 10t sprocket that came wit the motor had a ton of slack. So I appreciate the info where I could get a new sprocket :thumb:
 
The front sprocket and axle is still solid, no movement :thumb:

No cutouts today, but it dosent have to mean problem solved. (but I sure hope so :wink: )
It will take some more tests to be sure.

I hit a tree today, I just hate when those things run out in front of you :roll:

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Maybe I should have made a mold for the front cover, so I can make new ones when necessary.
But I am not sure it is really worth it, it is a lot of work.
 
I was out riding again today, and I learned that the cutout problem is not solved :(
This time it was a bumpy track, with lots of rocks and roots. It seems to be those kind of tracks that are the most problematic.

I also tried to do some filming, but the result was useless.
I had the camera on the handlebars, it is bumpy :wink:

But the biggest problem is that the camera angle was off, so you can hardly see the track.
I thought I had it set up decent, but an incident changed things:

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A crash broke my domino throttle, and the camera mount.
The throttle still works, and I was able to re mount the camera. But not in the right angle..
 
I've not seen this come up much but sudden speed changes may be causing problems for the controller, it might not be able to respond quickly enough to them and is getting overloaded as a result. Maybe it's something that can be addressed in settings but it's possibly also causing some shaft breakage issues in other projects, rotor inertia putting much more load than intended on the motor shaft. If you've got a rear wheel with a cush drive that wouldn't be too hard to fit it could be worth trying it out, it will add more unsprung weight but if it solves the issue it would be worth putting time into damping shocks elsewhere in the drivetrain.
 
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