Legit DIY Onewheel XR build guide

[Enginir]

You guys! it totally worked!

Just done with my diy onewheel project, it was super fun to ride, easy to make and cost is very little comapred to pint&xr, since i saw so many dudes struggling on a onewheel build, i’m gonna share how to do it the simple way.

PART LIST here we go.

1.Phub-188 48v 800w hubmotor with tyre bough for $112 on ALIEXPRESS

2.DIY 12S1P SAMSUNG 40T BATTERY PACK $60 (177wh)

3. 2x Customize CNC space grey anodized aluminum rails ~$120 ordered from local CNC shop

4. 2x CNC milled aluminum underpads ~$75 ordered from local CNC shop

5. 2x CNC milled wood footpads made from my fathers wood hanger factory

Dish shape double concave designed to lock foot in for carving.

6. TRAMPA VESC6+ (onboard mpu9250) $175 bought long time ago

But I just checked
trampa went little nuts asking for 236$ each, but no woreies later i will design my own vesc 6+ specially for diy onewheel, will sell for like 100bucks, for now lets use trampa.

7. 3D printed front&rear bumper
   
   
   
   
   
   
   total cost is around $500

GUIDE
to be continued
a detailed video tutorial is being edited by my friend, should be able to come out soon on youtube channel: Enginir

I drove up to a nearby city to meet up with 6 onewheel owners, let them tried the diyonewheel i made, after several ride and pid tuning on the vesc tool, they said the feeling is 80% close to the onewheel pint, but sharper, not as floaty due to the phub-188 tyre profile being too “pointy”( the contact patch is not as wide as the tyre in the pint) but it definately has more fun when carving and maneuver in tight corners.
they also own dandan,actually everyone of them bought dandan D2, they said the dandan is no where close to this diyonewheel in terms of balacing strategy(huge thanks to freedomcaller, he wrote the balacing app on vesctool) , the dandan is extremely unstable and cause one of them to quit onewheel forever after hiting head after a serious nose dive on dandan.

several video about comparing the pint and xr, diy tutorial is expected in few days so stay tuned.

I also made several cnc parts and footpads, hit me up on diyonewheel@gmail.com if u guys want anything as showed on the post.

And thank u all for taking ur time to check all those shitty picture lol.

Peace.

[Helno]

What kind of speed are you getting out of the 800 Phub on 12s? Others have done similar builds and it appears to be a bit speed limited due to the lower kV when compared to the real one wheel.

[Enginir]

I havent tested speed yet(nose dive), but it feels like speed mode 2 on boostedboard, around 25km/h is my guess, i wont go any faster than that. and u can tune the duty cycle tiltback to 90 to avoid any speed limitation

[Enginir]

This is my footpad sensor set up, designed this thin flexible pcb and tape the velostat on top of it

[Bionic24]

Welcome to the forum. Very nice build!

I would not set tiltback at 90%. It leaves very little room for the controller to give you the backwards angle while maintaining balance. Under load it is even questionable if the motor is able to reach much more than 90% dutycycle on a 1P battery.

I think 80% would be a better value.

Very interested in learning more about you tuning values.

[Enginir]

hi Bionic24,This is my config on the balance app, you are right its actually good to set the duty cycle tiltback at around 80 to leave some space for error margin, currently i am not experiencing any lac of speed even using 12s1p 40t set up. maybe they did change the hub winding? i can hit 11880 erpm at 49v(no load).

[Bionic24]

Sounds like it has a different (better) kV indeed. The original Phub has around 10, yours would be more around 16.

[NuRxG]

Anyone know how to use the terminal kv command? I never seem to get any results out of it.

[Bionic24]

This is with Madgwick filter? What is your Beta value.

Latest version of the firmware has more cool functions for you to explore like smooth filtering.

[Enginir]

actually i’m using mahony, madwick is kinda shaky didnt know why, my trampa vesc6 wont conect to vesc2.09 after the loading the new firmware so i’m using 2.03 for now, also i’m working on my own vesc6 with onboard mpu9250

had a quick layout and it looks like this, the mosfet are gonna be irf7749 aswell dont wanna cheap out on parts lol. it has a strip shape so it can be mount to the side of the rail hence free up the space in the front for more battery.

[Bionic24]

My gyro was too sensitive to bumps and stuff with the Accelerometer Confidence Decay at 1. When going off road or dropping from curbs the board would go ballistic. I am currently at 0.3 and it seems rock solid.

With Mahony filter I see a lot people having succes by replacing D value for a higher KP. So Mahony KP 1.0 and PID D at 0.

Looking forward to you build videos.

[Enginir]

here s the video enjoy lol https://www.youtube.com/watch?v=8j8RW86GRIY

[Bionic24]

Can you tell us more about your velostat footpad setup. When I tested it I could only get it to work with a spacer. The velostat sheet would just short the ADC and the 3.3V side. Do you use any additional (pull-up/down) resistors and what kind of values are you measuring when standing on the pad vs not standing on the pad.

[brycej]

What nuts did you use to attach the motor to the rails? Milled a D slot but I have a tiny bit of jitter and it is through the PID in a tizzy when shifts from one side of the D and back. Your nuts look a little smaller then the ones it came with.

[Enginir]

My nuts are custom made ,its a cylinder nut so it can pass away the load from the axle to the outter side of the aluminum rail.

[Enginir]

I used a pcb which has 4 resistors on it as voltage divider, i didnt use any spacer, it works perfectly, even better than the ones on pint. its basically a flexible pcb which has 4 cables not touching each other, and the velostat shorts them to pull up the adc value, u can not just use them without a divider circuits. in my set up,step off is around 2.35v on adc1&2, step on is 3.2v both, i set the falut value to 3.0 which has worked great.

[Enginir]

oh i have had the same problem, u have to mount the axle firmly, otherwise the pid is not gonna do the trick with the axle turining even a just little bit in the frame, thats why i ordered these nuts, they keep the axle in place for the software to do the job.(had to use loctile 638)

[Enginir]

Any inputs for the price and logo design is welcomed

[NuRxG]

That looks sick. I want one!

I’d toss my current frame in the trash and actually finish my build LOL!

[Enginir]

Thanks for supporting mate, u gonna be a happy customer lol