I recently decided that it would be nice to be able to replicate some of the costume pieces I have been making (strongly considering Halo 4 Spartan armor for the wife and I this Halloween). Another goal of mine is to make them a bit lighter (the
Knight armor in particular was ridiculously heavy - all that sheet metal definitely adds up). After some googling, I decided to try to make a Vacuum Forming machine.
A vacuum forming machine heats plastic sheets until they are pliable, and then uses a vacuum to suck the plastic into the shape of whatever is underneath it. Below is one of the first things I formed with the machine (the Nerf Spectre that I painted for my
Steam Punk Costume). It is hard to tell from the picture, but the detail on that pull was pretty spot on.
Volpin Props and
Shawn Thorssoli were HUGE sources of inspiration for me on this project. I was constantly referring back to their builds when designing my machine. I originally considered picking up one of the hobby formers that
WidgetWorks sells, but you have to put their frames in an oven, and then press it onto your vacuum surface - and my oven was too small for the 24" by 24" sheet size I wanted to make (plus the wife gets a bit cranky when I clutter up the kitchen with all my random crap).
Anyway, the first thing I did was build a frame for the vacuum surface. This consisted of two 24" by 24" sheets of MDF, and a bunch of 2x4s and 2x6s. You may notice some similarities to
Volpin's base - this is because I copied that part as closely as I could.
The vacuum surface consisted of a bottom layer of MDF with a hole cut in the middle for the adapter I glued on for my
Shop Vac. I then glued in some spacers so that the two layers of MDF would not collapse into one another from the vacuum. The top layer has 1/16th inch holes drilled 1 inch apart across the surface. All of the edges are sealed using
3M Fire Block Sealant because I needed it as air tight as possible, and didn't want to use anything that might melt if the temperature of the unit got too high.
The next element that I built was the oven box. I made a number of mistakes here which cost me some time and money - I highly recommend that you do not repeat them. I read somewhere that standard heat lamps would put off enough heat for vacuum forming - this is a dirty lie. Despite seeing other feasible heating options out there, I decided to go with the heat lamps because they would be easy to mount and wire... this was a mistake.
Needless to say... the heat lamps did not heat the plastic enough to make it pliable (just got one sad little saggy piece directly under each lamp). Mistake number did not require me to start a component over again, though it probably should have. Without really thinking about it, I built the over box out of 2x6s and a sheet of plywood. I later read that Hardibacker cement board should really be used as it is more heat resistant and such... I kept the build as is, but I keep a fire extinguisher handy just in case (probably a good idea either way). I would recommend going with the Hardibacker to start with just to be safe.
After replacing the heating element I discovered mistake number three. Once I had the oven box built, I covered the interior and bottom with
Self-Stick Foam/Foil Duct Insulation and sealed the edges with
Foil-Backed Tape. Fun fact: If your heating element will deform plastics, it will also melt the adhesive in your Foil-Backed Tape, which will then start to fall onto your heat elements.
I tried a couple of ways to get around the melting adhesive, but ended up making an inner box of sheet metal, placing that inside the insulation/wood box, and mounting the heating frame within there. For the heating element itself, I followed in
Volpin's footsteps and sacrificed a couple of cheap toaster ovens for their heating elements. This gave me eight heating elements which provided plenty of heat and deforms the plastic quite well.
I used two more 2x6s to mount the oven box above the vacuum surface. I liked Volpin's idea of using the drawer rails to slide the frame up and down, but I could not find any suitable rails for the height of my system (the rails would have had to be three feet long). My work around was to use a 72 inch Sliding Door hardware set which I cut in half for each side of the frame (two sets purchased, four rails total).
I took apart the rollers, and bolted them to a block of wood and a corner brace in order to form the brackets that the frame would slide into. I considered bolting the bottom half of the frame directly to the brackets, but I wanted to be able to switch out the frames easily if I decided to make some smaller ones.
The frames themselves are just four pieces of trim connected with more corner braces, and held together using pieces of aluminum L channel (thanks again to Volpin for this idea).
At this point, I had a functioning Vacuum Former, but raising, holding, and lowering the frame was a pain in the butt.
Volpin's second former used a lever system to raise and lower the frame. I liked that idea, but I did not want to raise and lower the lever the full height of the forming machine. I used a system of pulleys and picture wire connected to each bracket instead. This allowed me to raise the frame the full distance while only lifting the lever about foot.
The last touches I added were some weather stripping around the vacuum surface for a better seal, and a switch box on the front to turn on the heat sources and the vacuum. The left switch turns on the Shop Vac, and the two on the right turn on the heating elements (I had to put the eight heating elements on separate circuits because they were blowing my breaker when they were all on one and wired in parallel).
Hopefully now I can make some cool stuff to post on here with my new Vacuum Former. Here are the first two pulls I took with the machine:
