THE CAD IS COMPLETE! For now. Took about 2 hrs to finish the rest. I added screw holes for the rivet nuts and any threaded inserts. The plan is to use M4, M5, and M6 screws for this build since I already have those screws lying around. I added bumpers to the front fenders for extra protection and drilled some extra holes in the aluminum extrusion to route the wires. As of now, the CAD should be complete, and I may edit it later once I get the parts.
Been a while since I worked on this, but I made a ton of progress and did a ton of off-camera research. First of all, I decided to go from a 14s2p battery pack to a 16s2p pack because I didn’t realise that the hub motor is rated for 60V, but there wasn’t enough space in the compartment to store that big of a pack, so I had to spend some time in CAD to extend the overall length by 2 inches. A few other things I did: I decided to use aluminum sheets for the base; the footpads are now 3D printed instead of wooden (I might go back to wooden, not sure yet), and I decided to use both electronic footpads and a remote control for better and safer riding. Now there is just some polishing to do in CAD, and then its just building the actual thing.
Made a lot of progress today. I found a 3D model for a scooter hub motor that had a very similar shaft to the actual OneWheel motor I was going to buy, so I used that model and did some detailing on the tires.
I added LED strips to the front and back for nighttime riding and a latching button and barrel jack for charging and turning it on. Next up are the screw mountings for all the pieces, and I think that’s it for the CAD
Figured out the battery pack! Honestly went way smoother than I thought it would, and now we have a battery pack that fits, plus some extra room for the BMS and any wires to add. Took a bit of research to figure out a way to clear some extra space on the board without increasing weight or sacrificing strength. Next up is a few external circuit upgrades that I want to add that official OneWheels don’t have.
Worked on most of the frame, finished a few parts like the electronics housing, the footpads, and the fenders. I also decided to use a 21700 custom battery pack for power. The plan is to use a 14s2p config, so 2 rows of 14 cells, which adds up to 28 cells. Not sure how to fit everything yet.
I ended up pivoting back to a hub motor because I found this kit online with a hub motor, ESC, and a few other parts that are perfect for a OneWheel. I modeled mockups of the components based on the dimensions given on the website and came up with this basic design. Next up, I need to figure out the battery.
So I found out that getting aluminum machined stators and rotors for a hub motor is super expensive, so instead I’m planning on using two 6.5” hoverboard hub motors joined together inside an official OneWheel tire for a custom hub motor. It doesn’t fit perfectly, but I think it’s still workable with some metal adapters or if I change the tire.
Did a bit of detailing for the actual wheel. I designed a basis for the stator and the rotor for the motor. Measurements need work, but it’s a start. Also added a tread pattern on the tire.
Finished a basis for the design. For the tire, I’m going to be using the official OneWheel Pint S Performance Tire. For the frame, the electronics casing will be made either with ABS or some other strong plastic or some kind of metal. I want to design my own hub motor from scratch (literally starting with a metal coil and magnets) since hub motors for this size are super expensive
Started working on the project today. The first part I’m working on is the driving base. For that, I’m using a 6374 170KV motor for the torque, combined with two 6-inch lawn mower wheels joined together for its base. The plan is to use toothed belts and pulleys to transmit motion from the motor to the wheels, but we haven’t designed that part yet.
Couldn’t decide between using steppers and servos, but I eventually chose steppers for the robot arm. I started with designing a base and a cover for the base stepper. The plan is to use a cycloidal gearbox for each of the 6 motors for 6DOF. I found this reference model of a cycloidal gearbox for a NEMA 17 stepper, and I’m ONLY using it as a reference. I’ll design my own completely from scratch and will use that instead.
Did a little more work on the neck design
I’m not entirely sure how this is going to work, so right now I’m kind of just freestyling
Worked on the Neck Mechanism for about an hour and a half, and I also modeled the base shape of the head. For the head to move like a real droid, it would need 3 servo motors for the roll, pitch, and yaw angles. I decided to use 3 MG996R servos for each joint because they’re pretty good, cheap, basic servos, plus I already had them lying around.
