Thursday, May 29, 2014

Vac-U-Form, used for making HO scale parts and details

Did you have one of these when you were a few years younger?

Well I did, and I wanted it back, so I went out and bought a used one.  Generally, when you buy something that old, there are pieces missing, and/or it does not work.  Thankfully, someone else wanted to preserve and use them, so there is a company that has some parts and rebuild kits.

Discover unique and innovative parts and accessories for your Vintage Mattel VAC-U-FORM thermoplastic vacuum machine.

what's available:

  • Products to repair damaged or defective components
  • Products to improve the performance of your VAC-U-FORM
  • Economical replacement plastic sheets - up to 30mil!
  • Helpful user information
  • Nostalgic VAC-U-FORM advertising



Share your ideas and experience with the VAC-U-FORM community.
VAC-U-FORM is the registered trademark of Lo-Tek Inc.

After acquiring the Vac-U-Form, I ordered up some plastic sheets and the full parts kit.  By now, I have about $50.00 tied up in this project.  Certainly cheaper than a new HO scale locomotive, but I didn't know if it would work.  

The projects that I had in mind were a canoe, a row boat, and making wind shields for automobiles.  First, however, I gave the machine a try, just to see how it worked.  I tried it without the upgrade/parts kit, and it lacked enough suction to pull the plastic down around the molds, or so I thought at the time.  Although I was probably right about the suction, even with the upgrade kit, things did not work right, as I was not getting the plastic clamped in the holder tight enough.

The upgrade kit includes and plate to cover the hat plate, thus holding in the heat, and getting the clamp hot.  The plastic sheets available now do no have holes in them to fit the prongs on the clamp, so the clamp must be hot enough to melt in to the plastic in order to hold it solid.  I hope that makes since?

 The used machine I bought did not come with any molds, which was fine, as the only one that I remember that might have worked was the boat.  Regardless, I had to make my own molds...bring in the 3d printer.  I was in need of some tile roofing for a project, and did not find any HO scale that I liked.  So, that and the canoe mold were in the first couple tests.

 This is the first one that came out almost reasonable.  The tile to the left could be cut in to strips, and although the plastic did not pull down tight in the corners around the canoe, it looked usable.

 The plastic supplied has a glossy side and a flat side.  The black sheet in this picture has the glossy side up.  To show the cut lines, I used a white paint pin on the black plastic, and a pencil on the red.

 Once cut out, it is easy to see the backs of the boats were not formed well, and will have to be built up from styrene.

 I am adding some details and reinforcement to see what looks right.  I ran out of red plastic, as I wanted to finish the well roof before I did this post, but it will be another week before I get more plastic.  I will do a post on the well by itself at a later date.

 I cut off the back end of the boat, and replaced it with some styrene, which incidentally, solvent welded to the Vac-U-Form plastic just fine.

You can click on the pictures to make them larger.
 I do have some cap shingles I formed, but can't put them on till I get more red plastic...

 which I would have had, if I had not screwed up this sheet and another.  The is what happens when the sheet is overheated.  The glossy area on the right is so thin it is clear and it broke open, breaking the vacuum.  Maybe two of the rows of tile will be good, but I needed four to finish the project at hand.  The other pieces are to be cut for caps.

This is about the best I have gotten!  For the record, this was preheating for 15 minutes with the plate to hold in the heat in, in place.  Drop the plastic in and use a spring clamp to hold it tight, wait another five minutes, then put the plate on for 15 SECONDS.  That's right, 30 seconds and it melts through like the shot above in red.  If you look close, you can still see some gloss on the right side where it got a little too hot.  Note that the back of the boat is formed perfectly.  I don't think that with this technology from the 1960's I can get much better than this.

It is also important to point out that with each failure in the Vac-U-Form process, I also found issues with the molds.  This is the third rendition of both the boat and the canoe molds.  Adjusting for air holes and getting what was to be the final product down as close to the surface as possible.  Each sheet costs about a quarter, so when a print fails, you just wasted about 20 minutes and threw a quarter away. :)

More later as I get these projects finished up.  Not sure what else I can use the Vac-U-Form for, got any ideas?

1 comment:

  1. Interesting. I was looking at the machine Micro-Mark is selling .. and trying to think of what could be done with it,11244.html