I’ve had quite a few projects where a vacuum forming machine would have been a huge help. It wasn’t until I found a great site with a step-by-step tutorial on how to make one from scratch.
Unfortunately I neglected to take photos during the early stages of this project. Due to limited space, I decided to build my machine where the oven would hang upside down over the forming surface. I built the supporting table high to alleviate too much stooping over. The vacuum surface is 21.5″ x 21.5″, made with MDF and covered in aluminum.
Since I can’t weld I made my plastic-holding frames from canvas stretcher bars (like painters use). Inside I applied no-slip tread for a firmer grip. The lower frame is attached to a pillow block bushing that allows the frame to slide on steel rods up and down from the oven to the vacuum surface.
I cut a hole in the bottom of the table and made a flange out of one of my shop vac’s attachments.
The frame guides were secured to the table with these plastic brackets, although in hindsight, I could have just epoxied them in place.
Here is the completed rail system.
The oven surface was made with concrete board.
Ceramic posts were attached according to the tutorial.
The sides were cut from leftover concrete board, attached with scrap aluminum and sealed with furnace caulk.
The NiChrome heating element wire was a bear to figure out. Each segment had to have equal resistence for even heating. With the help of the oven calculator, and much advice from friends and the TK560 board, I was able to get the segments exact!
I built a supporting wooden structure to hold the oven. Please excuse my crap carpentry!
Up until this point I had not yet decided how to support the oven over the table. Just in time, my friend Jeff gave me some Gorilla Racks and I happened to have some parts left over!
I attached a shelf support to either side of the wooden oven box, and then attached the vertical rack posts to the table. This also allowed me the freedom to change the height of the oven if I needed to.
I attached the Gorilla Rack bracket to attach the oven to the supports.
The wires were attached to the segment posts and run out a hole to the switch. The wires attched to a 20 amp switch.
The oven inside the supporting wooden frame.
To allow for a tight grip on various thicknesses of plastic, I used window sash locks on each side.
A friend sent be some pillow blocks that allow the frame to slide up and down.
I used an ordinary light switch to control the power. I also installed hooks to hold the frame up against the oven opening.
The whole unit ready for a test.
For my first test “pull”, I wanted to experiment with different types of objects: A large smooth-sided unsanded MDF dome, A small unsanded MDF dome, a small flat-sided sanded shape and to fill the space a pocket knife and wrench. All pieces a placed on plywood risers placed on washers as not to disrupt the airflow.
The first test pull may not be considered a success my experience formersa but I was just giddy that it actually worked! The “tenting” between shapes can be corrected by adding more space between the forms. I expect a big shape like the large dome would have to be pulled by itself.