Far and away, the most frequently broken parts on an Omega Supreme toy are the drums that drive the walking mechanism. The plastic is a little too thin and brittle, and if the release levers aren’t used correctly it is easy to put way too much force into them in shear when transforming the toy.
This is a shot of the repaired walking drive assembly back in the toy. In the foreground, you can see the pile of broken bits that was left of the old drums.
I measured these parts and have made a parts tree that is on my ShapeWays store. I sell a tree to replace a single drum or a tree to replace both drums. http://shpws.me/RLtL
The parts tree provides replacement plastics for the Drum, the Pin, and the drive housing. Most broken Omega Supreme toys I’ve seen still have the screw, spring, and original pin still captured in the drum. If they are there, great! You can reuse them.
If they are missing, I found suitable replacement parts from McMaster Carr. I really like McMaster Carr. The link for the spring is: https://www.mcmaster.com/9657k601 and the link for the screws is: https://www.mcmaster.com/90380a005.
So, even if your drums are completely wrecked, you can order the printed parts from ShapeWays and the hardware from McMaster and replace them.
Typically, if the original pin is still present, I reuse it instead of the 3D printed pin. The original pin has a smoother surface, and I suspect performs a little better.
Rebuilding the drum is straightforward. Put the pin through the hole in the drum that it fits through (from the inside). Put the spring behind it. Push the drive housing on, and run in the screw. In this picture below, I’m reusing everything except the drive housing. The pin is already in place and the spring is sitting on top.
The drums are just a slip fit onto the square shaft, and are essentially free to fall off until the rest of the toy is reassembled. When putting the driveshaft back together, remember to align the pins 180 degrees away from each other. Otherwise your Omega wont walk, he will just sort of sway.
When fiddling with this, there is a metal counterweight piece that tends to just fall out of the toy. It may not be obvious where it came from or how it goes back in. Below is a reference picture.
When putting the shaft back in, make sure the cam that pushes on the metal tabs for the light lines up correctly. Also make sure the gear is making good contact with the driving gear. It is just a press fit on the square shaft, and its position may need adjusted slightly.
From here, just reassemble the toy and you should have a fully functioning Omega Supreme again!