You can actually make a homemade vacuum-forming machine pretty cheap and easily. I did it a few years ago myself (read about 10). Here is a list of the supplies you will need:
- a 5” x 9” metal loaf baking pan
- a section of heavy metal mesh (I actually used plastic mesh, but would use metal if I did it again)
- some PVC pipe
- some pieces of "L" shaped aluminum
- scrap pieces of ¼” basswood
- four machine screws and wing nuts.
The bread pan is your base. Cut a hole in the side of the pan that will accept a piece of PVC pipe that is the size needed to hook up to your vacuum cleaner hose. Epoxy the PVC to the pan.
Next, use a couple pieces of 1/4 inch bass wood going across the inside of the bread pan with holes drilled in them to allow air flow. These will be your internal bracing so the metal mesh doesn't collapse into the pan when the vacuum is applied. Epoxy them in as well. Now epoxy the metal mesh to the open top of the bread pan. You should now have a bread pan with PVC pipe sticking out one end, wooden braces inside, and topped off with a mesh top. The vacuum chamber is complete.
Now you need to make the frame to hold the plastic. Using the “L"-shaped angled aluminum; bend it into a square just big enough to fit over the meshed top of the chamber. You need to make two identical frames. Once these are completed, the two frames need to be held together, drill holes through both frames and place screws with wing nuts to secure them. The plastic sheet gets sandwiched between the two frames.
Your vacuum machine is now complete. To use it, simply carve your master and place it on the mesh. Take your plastic sandwiched in the frame and heat it over the stove until it visibly droops in the frame and bows down. Turn on your vacuum and quickly transfer the plastic in the frame from your heat source and bring it down over the master on the vacuum machine. The vacuum will pull the plastic down to the mesh and around your master making an exact copy of it. It is pretty easy to do.