Easy permant strong fix bro just put a drop of cheap super glue gel on metal Axle, them slide hex on. I glued the hex to the wheels and hasn't slipped since. I've got them solid with rtr parts, but these are doomed with brass motor pinions. Stock plastic output shaft gear will slip next and is not fixable. The single speed is cool can go fast if you remove the reduction gear case on end of motor. The mn78 has a awesome metal transmission with metal gears, just sits too high have to cut C24 floorboards

I can't believe you got them portals to work, nice work

Looks like a beast

Nice work