The author remixed this model.
Mostly changes are for the look, but there are some added little features.
1. I keep the weight at 200 grams each.
2. I added slots on the back so if water gets inside the axle, water can drip out.
PS. There is no thread in the step file. If you want to have it machine out, you should specify 5/16"-18 UNC-2B for original XR bolts.