Let’s make a wheel

[rollingbender]

My “transformation of a Chinese scooter” build is about to make a big leap by installing a short case 125cc GY6 crate motor. In order to weld the new engine hanger to the frame, I need the rear wheel to establish the centerline. Trouble is…. I cannot find a 10” rim. The 50cc rims have the proper splines and brake drum to fit my engine but the dish is wrong and the rim hits the case. A 50cc rim has about an inch between the edge of the brake drum to the left edge of the rim. I have established that this distance needs to be .3125 to have the rear wheel centered in the opening of the engine case. 

So… I will make my own by modding a 50cc rim. 

The rims I bought for the project have 16 curved spokes. I cannot easily duplicate these rims but hopefully what I end up with will at least match the design. 

Here’s the rim we want to match…




And here’s the rim I’m going to modify…




I started by cutting out the spokes with a jigsaw. Wow, this Chinese aluminum is SOFT!!!




Then I removed the remains of the spokes from the hub and made it true by turning it on my lathe using an axle as a mandrel. So far, so good!

Now I need to remove the spoke remains and true up the outer ring of the rim. Not so easy. I clamped the rim to the bed of my CNC mill and used the machine to take a whole bunch of measurements but I could not find a spot where the rim was actually round. Blame it on the casting. I flipped it over and tried again and BOOM, round on the first try. I guess I’ll have to start from the back to true up the inside and then flip it back over to remove the last bits of the old spokes. 




Next will be to cut out the new insert to go between the outer rim and the hub. I’ll cut this out of 3/4” aluminum plate on the CNC. I have it all drawn up and the code created to make the cuts. Here’s an animation of the cutting process


Now I just need to round up a piece of plate to cut it from. After the insert is made I will TIG weld the whole assembly together. 

[snaker]

WOW, I choked on my coffee on this one.
But then I noticed the milling table in a photo, so, hopefully the skills and equipment match the job.
Even so, this should have a giant "DON'T DO THIS AT HOME KIDS" warning.

Looks good.

[90GTVert]

This is an amazing project. I was impressed with the scoot itself, but you are really going above and beyond into areas where few would dare and fewer would have the skills and equipment to pull it off. Thanks for sharing it with us.

[rollingbender]

Yea..I forgot the disclaimers
Don’t try this at home
Hold my beer

Here’s my mill (that I now have stuffed in my garage).

[aeroxbud]

This project has taken a turn into parts unknown.

[rollingbender]

Learned a couple new tricks in the course of drawing this up!!!

Here’s the 3 components of the rim all joined together. I’m pretty happy with this. I just need to draw in the hole for the valve stem so the mill doesn’t run it over when I clean up the remainder of the old spokes.

[rollingbender]

Clean-up and truing of the old rim has begun!




Getting the last bits of the old spokes out of the nooks and crannies will prove to be a bit of a programming challenge….

[Kaos]

Dude, thats next level. I'm quite impressed!

[rollingbender]

The mill is milling!!!

[rollingbender]

Setting tool heights for machining the back side…



End of machining the back side. You can see a series of tabs that I left between the part and the stock. Bad things happen if you don’t do this or have both pieces clamped down. The tabs are cut with a jigsaw and cleaned up with a pass by the belt grinder.



The result was a nice slip fit between the 3 components. I will be making a welding jig from the sacrificial plate that I had under the work while doing the machining.



As long as I was doing this I made a last minute additional feature by adding scallops to the spokes.



…and mocked up on the case…



Now to make the jig and off to my friendly TIG welder dude!

[rollingbender]

It took a lot of work in the computer, checking and rechecking dimensions, angles and radii but I finally got everything on the drawing to match the actual rim and was able to clean up the last bits of the original spokes (mostly).



A bunch of sanding and a whole lot of time on the buffing wheel and I think that I have shown that it possible to polish a turd!

[90GTVert]

That's beautiful work that looks way better than what you set out to match. More impressive still is that most people will probably see it when finished and think nothing of it; not having a clue what was involved. Heck, I'm proud/happy when I get something very simple to turn out OK on the mini-lathe. If I did that I'd be knocking on doors showing it off or call the local news. 😆

[sinfull]

Really great work 👏 👍

You going into the custom wheel business ??

[Kaos]

This is beyond amazing. I'm very impressed. I wish I could do something like this... Then maybe my wheels would match

[rollingbender]

Feb 6, 2023 18:17:23 GMT -5 Kaos said:

This is beyond amazing. I'm very impressed. I wish I could do something like this... Then maybe my wheels would match

Yea… now I’m thinking about doing this treatment on a front wheel so that they absolutely match😡. That would also give me a chance to get rid of the mechanical speedometer stuff and keep things looking clean.