Simple but Strong Wheel

I printed with supports, I'm not sure if you really have to or not.  The wheel is symmetrical.  I printed in PLA and really cranked the infill and layer counts as I used this to move a greenhouse around.  The center axle is designed to accept a 12.7mm (½ inch) bolt.  The diameter of the wheel is 190mm (~7.5").

Included is a small bushing to keep the wheel from rubbing, but it is optional depending on the application.