3000W Electric Unicycle Build!

It’s not an esk8 build but I feel an electric unicycle is more akin to an eboard than an electric bike so I’ll post here.

I am planning a build similar to the Gotway with a more powerful 3000W motor with a 20.9”x2.75” tire. It will have a 20s3p 30Q battery and will be controlled by gyroscope and accelerometer connected Arduino with a DAC output to control a Kelly speed controller. I will make the frame out of 1” aluminum tube with CNCed plates brazed to the tube to hold the wheel axel.

This project is going to take a long time and I’m just getting a parts list together now and drawing up plans. I plan to log everything in this thread for anyone interested. Stay tuned for blueprints & parts list sometime in the next few weeks!

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I’d like to hear from anyone who has ridden or owns a commercial electric unicycle. What can you tell me about them? What design aspects do you like? What could be improved?

@psychotiller What was that crazy one wheel thing I saw you riding?

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Yup! Fun at slow speeds. I’d never go full speed on one again. Very unstable over bumps and uneven terrian. Had I not had my helmet on, I’d probably be dead.

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That bad huh. Which one did you ride? I assume a larger & wider tire might help absorb bumps. I’m going to get a dual sport 110/80-14 motorcycle tire.

I hate builds like this.

Build it then post everything at once. The suspense is killing me alresdy.

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If I do that I forget to take pictures until the very end. I want to document the process as much for myself as the community. That way I can just link someone when they ask me about it.

Could I do smoother single track trails around 15-17 MPH w/ a few months practice?

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Definitely!! But I’m not kidding about sudden instability. I was getting really good on it. Confidence is your enemy. Its heavy too. I was riding it at night in familiar territory. Road crews had been grinding our streets though, and I didn’t see the rut. It turned and started to run me into a new mustang. I planted my foot between the one wheel and the car and it turned/flipped instantly. The first parts of me to hit the ground were my head, my fist, and shoulder.

JT was on his board and I was riding along side of him. Fastest I got it up to was 19mph. Probably only going 15 when I fell.

Fun to goof around on. PLEASE wear a helmet on it though.

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Of course! Safety first!

So is that wheel DIY? If so who made it? I am a little worried about getting the self balancing software to run properly on Arduino and it would be nice to have contact info for someone who has already done this. I am a 3rd year computer science & electrical engineering student so I do already have a pretty good idea of what I am doing, but knowing a veteran always helps.

I think that, although the current implementation of the over-tilt protection isn’t bad, it could certainly be improved and made more user/commercially friendly.

I can’t speak for any brand or euc other than the ninebot c+ or something like that, but that one has very quiet beeps and decent at best tactile feed back that youre going too fast/ leaning forward too much.

I think making a super loud beeper attached to the Arduino shouldn’t be too hard

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Could you explain a bit more about the beeps? Does it allow the speed controller to go over continuous rated current but only for a short burst before give you a warning that it’s gonna cut power to protect from overheating?

That is my guess

Or does it beep to let you know if you lean farther forward it doesn’t have enough power to keep you upright and you will fall?

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Also an indication of throttle, like the amount left.

Riding in BLDC mode is nice because you always know how much throttle you have left, but with foc(the EUCs are quiet, I would equate them to foc) its difficult to gauge that off of the sound the motors make.

I little DaVeGa style cluster inbetween your crotch or something with a hyper visible screen that shows current PPM position

idk something like that :man_shrugging:

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so there are two scenerios when it will beep and provide “push back”

a) you lean your body too far forward for the device and it is thrown out of wack and it gets very angry. It will try to push your feet back and will beep angrily.

b) If youre traveling too fast, it will let you know when you reach the max speed of the EUC, and then apply the “push back” to apply breaks, and will beep if you continue to speed up. BUT BUT BUT IF YOU CONTINUE TO SPEED PAST THE WARNINGS IT GOES COMPLETELY LIMP

THAT NEEDS TO BE CHANGED

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If youd like Id be cool sending you my ninebot to toy around with

just got to send it back in one piece :rofl:

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That would be super super awesome if I could!!! I really wanted to buy a commercial electric unicycle just to try it out but I couldn’t really justify spending all the money for something that I would only use until I finished my own DIY build.

We can work this out in the future. I can PayPal you for the shipping and everything. I wouldn’t want to have you send it until it is nicer though. No place to ride in Minneapolis until late April.

this is what happens when you don’t listen to the beep

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