Monday, December 28, 2015

Vacuum Former 2

A few Years ago I made a simple vacuum former in my small apartment in New York.  I drew up plans for this in Adobe Illustrator - these were the days before learning how to use SketchUp.

You can see my original build by clicking here.  But essentially it was constructed with a few 2x4 pieces of wood, a little plywood, peg board and tape.  

I was able to make a few things with it, namely a few Stormtrooper helmets...

...and a TIE fighter helmet.

I also made a few visors for my X-Wing Pilot helmets...

...and my Daft Punk Thomas helmet.

It was such a simple and inexpensive build that when it came time to move I didn't even bother taking it with me.  And now I think it's time I build a new one, a better one.  Now that I know SketchUp I can build one in 3D to size.  I also have a home now with much more space, so I designed one which will have legs and stand off the ground. 

It's still a simple design for the forming chamber seen above.  Below I will make the frame - which holds the thermoforming plastic - and it will fit perfectly in the chamber.  

My first frame that I built years ago was a simple 2x4 wood frame that I stapled the plastic to.  This frame will open and close, so I no longer need to worry about staples.

I'm also going to make a cover for this whole thing... that when not in use, it could pass as a piece of furniture.

With my designs done, I color coded each part...

...and laid it out so I know how much wood to buy from the store.

At the time I started working on this, money was tight, so I started by just making the main former box and frame.  I can always add the legs and top later.

The box will be made out of MDF.

I cut the pieces I needed on the table saw.

Then I laid out a grid using my T-square and a pencil.

One by one I began drilling holes on the grid...

...until I had the top of the chamber done.

Next I drilled a hole in one of the side pieces.  This hole will be where the vacuum hose connects with the chamber.

Then I began adding construction adhesive to the side pieces...

...until all the sides were made.  Each side consists of 2 pieces of MDF.

When the sides were dry I attached them to the bottom and clamped it in place until dry.

Then I added the top with more adhesive and clamps.

While that dried I began working on the frame.  I cut all the pieces I needed with the miter saw.

Then I drilled pocket holes on the pieces that needed them.

I assembled the frames using a face clamp and pocket screws.

Before long both sides of the frame were done.

Next I clamped the 2 frames together tightly and attached a hinge in the back.

Now the frame opens and closes nicely.

It also sits perfectly on the chamber.

At this point I was going to attach some latches to keep the frame closed tightly, but the only hinges I could find were too big.  So in order to "lock" this frame I cut 2 more pieces of wood to make handles for the front.

I drilled pocket holes in each handle, and then drilled 2 ordinary holes and screwed the 2 handles together.

Then I took the screwed-together handle and used pocket holes to attach it to both sides of the frame.

Now when you unscrew it, the frame will open.  When you put a sheet of thermoforming plastic inside, screw the front handles together and the whole frame will be locked tightly.

When the chamber was dry, I used my dremel to widen the hole for the vacuum hose until it fit the hose perfectly.

Then I gave the whole thing a good sanding.

I added some sealant to the sides to make sure it was air tight.

Then I decided to test it out, using a garbage bag.

I placed it in the open frame...

...and then closed it and "locked" it.

I placed the frame with the garbage bag onto the chamber and connected the vacuum hose.

Here how it looks before turning on the vacuum.

And here's how it looks with the vacuum on.  As you can see the garbage bag is being sucked down.

Here's a second test, this time using a sanding block.

Here how it looks before turning on the vacuum.

And here's how it looks with the vacuum on.  As you can clearly see the block in the middle.  But I think the suction could be stronger.

So using a marker, I traced the inside of the frame onto the chamber.

Then I bought some rubber foam seal...

...and attached it outside the line I drew.

Now there should be a nice air tight seal.

I tried it once more and the difference is night and day!
(scroll up and look).

I decided to test it again, this time using the stormtrooper mold I was making.

Without the vacuum on...

...and with the vacuum on.

So suction is much stronger with the rubber seal.  Now that I have the chamber and frame done it's time to try real vacuum forming.  But sadly I have to wait for the plastic I ordered to arrive. 

While digging around my workshop I found one full sheet of thermoforming plastic.  YAY! Now I can test out the Vacuum Forming frame and chamber!

The chamber fits nicely on one of my kitchen counters.

The plastic sheet fit in the frame quite snugly.

And the frame fits in the oven.

Next I plugged the shop vac into the chamber...

...and brought out the front of my stormtrooper helmet mold and placed it on the chamber.

Next I heated up the oven and put the frame in...

once the plastic was ready I took it out of the oven, turned on the vacuum and placed the frame on the chamber.

When the plastic cooled I removed it from the frame.

It's almost perfect.  See those lines?  That was the plastic touching the oven rack.  I'll have to make the frame a little taller.

To do this I cut 2 equal sized pieces of wood...

...drilled pocket holes...

...and attached it to the frame with pocket screws.

Now the frame is raised 2.5".  The plastic now can sag 3.25" when heated, as opposed to .75".

Once I receive my new plastic sheets I'll try out the revised frame.  While I waited I thought about building the legs and the top for this, but then decided against it for the time being.  It's small enough that it can fit in the closet or a shelf in my workshop, or as pictured below - under my art desk.  If I wind up building a bigger vacuum former then I'll definitely make it more like a table, complete with legs and a top.

About a week after starting this project my thermoform plastics finally arrived!

These are White High Impact Styrene 1/16" thick and I bought them from  With my plastic sheets finally here, I set up the former with the front of the stormtrooper helmet on it.

Then I put a plastic sheet in the frame.

I heated the plastic, put it on the chamber, turned on the vacuum and voila!

I wound up making a couple of stormtrooper faces.

I even started making the back of the stormtrooper helmet...

...and all it's parts.

And for kicks I even vacuum formed an old U.S. Army helmet.

The vacuum former itself works like a charm.  The frame still needs a bit of work though.  The lifts I made for it work well, but they sit at the edges of the rack beneath it.  I had to do a balancing act each time I placed it in the oven.

In order to make it as best as it could be, I'm going to make new handles that are the width of the oven rack.  I measured the rack to see how much space I needed on the sides of the frame.

Then I cut the wood for the new handles.

Like the old handles, I cut the corners at 45 degrees.

Then I drilled pocket holes into the new handles.

I removed the old handles and lifts...

...and attached the new handles.

The length of 2 handles on each side was greater than the length of the frame, so I simply cut off the excess with a small saw.

New frame with handles complete.  Now to test it out.

Unfortunately the height of the new handles are greater than the grooves in the oven.

So I set up my router table to thin out the thickness of each handle's edge.

Now the frame fits inside perfectly!

My next attempt at vacuum forming will use an X-wing pilot helmet mold.

I placed plastic in the frame...

...then the frame in the oven.  It fits perfectly!

... and voila!

 The Vacuum former itself works great!  Learning how to make proper molds for vacuum forming is another story... but that's a story for another day.

Thanks for reading!


  1. Marvellous work, Tim! You'll be getting a pizza oven next - then you'll be able to do the whole trooper suit!