You can print all parts without supports, infill 20 percent is more than enough. To complete need 2 bearings per wheel, and 1 nut M8 with length of 70mm at least. To join parts together I use M4 bolts with nuts.

if you need washers, see [https://www.printables.com/model/1089868-washer-1mm-thick-inner-diameter-81mm-outer-diamete](https://www.printables.com/model/1089868-washer-1mm-thick-inner-diameter-81mm-outer-diamete)