Designed this for a friend who wanted to make bath bombs. You will need 2 of the inserts and one of each of the other parts. Simply add 1 insert to the body, add the desired material and then the second insert, and use the plunger (press) to compact it and then push up from the bottom. I printed it in petg but pla will work as well. 

The inside is 38 mm wide but it can be very easily scaled up in your slicer if needed

No support 

Easy print