Iteration Cast Foam Wheels

The process starts by importing a CAD file for a pulley that has the correct profile and tooth count

A construction plane and the split body tool are utilized to get a clean profile view of the pulley, which is then projected onto a sketch.

A new body is created with the correct bore size and proper offsets for the pulley. Chamfers and fillets will be added later, only the critical dimensions and profiles are needed at this point.

An additional sketch is added to the end of the pulley. The outer circle is the wheel diameter, and the inner two dimensions are the printed retaining hub.

The core and retaining cap are extruded.

The retaining core is roughed in

I decided to actually truncate the upper hub in favor of only having foam on the outside edge of the wheel. This should allow the foam to take a few additional impacts before having the hub take any damage. Another added benefit is increased printability with less supports.

Retaining holes are added around the core to allow the foam to completely encircle the part

Chamfers are added all around the harder to print areas

An additional body is added to start creating the buck that the mold will be made from

The wheel has a 45 degree draft angle inside to allow for it to come off the mold easier and to trim some unnecessary wheel weight, as well as access to the wheel mounting bolt

A fillet is added internally for a smoother look

a blank mold is start

The tire and hub are cut from the wheel mold to leave a cavity

A construction line is added at the top of the tire to allow the mold to be split into two parts

The base of the mold, this is only needs one additional feature and a small lip to be removed to be done

The initial bottom of the lid before any additional work

The fill holes are extended so that they can reach the base mold

The pulley portion is cut away so that it can freely slip into the mold lid

A lip with a chamfer is added to the lid to help it center and be retained by the base

A small feature is added to the center of the base to allow the hub to align to the bottom. There is a small chamfer to help locate and seal the hole

The competed mold, time to get printing