I just finished my build of a OneWheel based on the ByteSizeEngineering build and I want to give my thoughts on the build and any lessons for people that want to do it as well. For anyone interested in following his videos, you can find them here. He has all the configuration files linked, as the dimensions for the frame and a 3D model of the whole design. He also sells a $20 build guide which I reluctantly bought. It was pretty helpful.
Parts:
- Motor: Pei Scooter Phub-188
- Battery: CaoMM 48V 20AHr Li-Ion Battery
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- I got a lot of crap for getting this cheap battery but it hasn’t given me any problems. I haven’t done a range test yet but it seems to be working well.
- ESC: FSESC 75100
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- The guide recommends you buy the FSESC 4.20 but I would highly recommend against this if you get a 48V battery. This battery will be ~54V when fully charged and even a tiny voltage spike will destroy the 4.20 which is only rated for 60V. I learned this the hard way. The 75100 is only a few more bucks and hasn’t given me any problems at all.
- Anti-Spark Switch: Flipsky Anti-Spark Switch
- IMU: MPU9250 ( Don’t buy from AliExpress. I got one with bad I2C pull-ups and didn’t work)
- Foot-Pads: Thin-Film Force Sensitive Resistors
- Bluetooth Module: Flipsky Bluetooth Module
- Frame: 2" x 1" x 6’ x 1/8" Aluminum Tube
- Miscellaneous
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- 3ft of 10 AWG Wire
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- 5.5x2.1mm DC Barrel Extender
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- 1k and 10k Resistors
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- 3.5mm Banana Plugs
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- Probably forgetting but most are just common sense stuff like shrink tube
Tools:
- 3D Printer
- Miter Saw for cutting aluminum
- Drill Press for drilling holes. You can get away with just a normal drill (I did) but I would not recommend it. If you do, make sure to use a center punch to make sure you get it in the right spot.
- Tri-Square
- Socket Set
- Since I made most of mine out of wood, I had to use a few more tools but you’ll be better off if you can 3D print most of it.
Build:
Unfortunately I didn’t have access to a 3D printer which made things difficult. I did outsource the end caps to someone to print for me but they were annoyingly expensive so I didn’t want to pay someone to print it all.
Instead, I made the enclosures and footpads out of wood. Basically just a 1/2" sheet of plywood that I cut and glued/screwed together. It was super tedious and I would not recommend especially if you don’t have a table saw or miter saw. They eventually came together pretty nicely but unless you’re a fan of the wood aesthetic, I wouldn’t recommend.
Random Build Notes:
- The battery I used was a bit bigger than the one from the guide so I had to expand the enclosure in the length and height directions. As a result, my aluminum pieces were 36" long instead of 34".
- Trying to line up the holes in the aluminum with the enclosure to screw them together is a little tough so I ended up just epoxying them together. Not the best solution so I would recommend just trying to line the holes up.
Electronics:
The inside is a bit of a mess but it all stays pretty still from the zip ties.
Here’s a zip containing my configuration files:
Config Files.zip (5.8 KB)
- Feeding the wires through the metal tube was a bit of a pain but keeps everything neat. I would try to put some rubber rings around the holes in the metal to prevent rubbing on the wires.
- The resistors for the footpads are part of the wiring harness and covered in shrink wrap.
- The 75100 FSESC makes it very easy to connect the PH2.0 connectors to the ESC.
- I am still trying to get the WS2812B LED to work. I’m having some problems with the code but that should be done soon which will make it much cooler.
Overall I would highly recommend going through with this build. It feels pretty close to the real thing and is a fraction of the cost. The build got a little frustrating at some points but that’s just part of the learning process. The board is a bit large which is kind of annoying. Unfortunately, I didn’t really think about this in planning and it has to be this big to accommodate the battery. I would like to add a handle to the side so it’s easier to carry.
If anyone has any questions, please let me know.
