Build your own plastic Vacuum former - Awesome

I did not write this, and am taking no credit for it, but it's all on this thread for you.Link to original Thread


Screw the nipple to the platen flange
Wrap several layers of PTFE tape (teflon tape) around the threads of the pipe nipple, where it will screw into the floor flange. You need several layers, because the tape is very thin, and you want to build up enough thickness to fill any mis-fits in the threads and make a good seal.

Now screw the pipe nipple into the flange, hand tight.

Wrap teflon tape around the threads several times before screwing them into the flange.

I did not write this, and am taking no credit for it, but it's all on this thread for you.Link to original Thread


Tips on using your vacuum former
I won't give detailed instructions for vacuum forming here---that's for another instructable I'm working on.

For more information on vacuum formers and vacuum forming, check out my web site, http://www.vacuumformerplans.com (It has links to several other good sources of information.)

I will give a few tips that are somewhat specific to this design, though:

(1) Pick a size of plastic that's appropriate for what you're making. You need some "extra" plastic between your mold and the inside edge of the gasket. A good general rule of thumb is that if your mold has steep sides, the extra area should be as wide as the mold is tall. If the sides are more rounded or gently sloping, you don't need as much. If you have too much extra plastic around the mold, you may get webbing. (Wrinkles caused by the plastic stretching too much and not being able to suck inward onto the mold without folding over on itself.) If you have about the right size sheet of plastic, and you're still getting webbing, there are other fixes; go to my site and click the link for the webbing article.

(2) Be careful about the binder clips; remember to make them flat against the bottom of the bottom frame, with the rolled edge a bit inward from the frame so that you don't tear up your gasket.

You will sometimes bring the frame down a little out of alignment, and dent the inner part of gasket with the rolled edges of binder clips. That's no big deal.

You can add guide rails to prevent this, and bring the plastic down straight every time. All you need is three strips of something reasonably stiff, sticking up just outside the gasket. If you put two along one edge and one along an adjacent edge, that defines a corner that you can nestle the frame into just before bringing it down, and press it lightly into the "corner" as you lower it. L-shaped guide rails can be clamped to the platen anywhere you want them, for different sizes of plastic.

There are designs out there for systems with their own ovens, which have a frame that pivots to raise the plastic off the oven and bring it down onto the platen. For a small former, that's not necessary. L-shaped clamp-on guides work fine, are adjustable, and let you bring the plastic straight down rather than swinging it in an arc.


(3) Put your mold up on spacers such as washers or coins, about the thickness of pennies, to ensure that there's room for air to flow under the mold and to the platen hole.

You can also use a piece of aluminum window screen under the mold, to keep the mold from sitting quite flat against the platen. For plastic up to about 12 x 16 inches, I often use a piece of window screen folded once each way, to make four layers, and no other spacers. This makes one thick, porous "spacer" under the whole mold, which air can flow right through. In effect, it makes thousands of platen holes, including hundreds right around the edge of the mold, where they count most.

(Even if you have a many-hole platen, one layer of window screen is a good idea. It keeps the mold from blocking the holes it's sitting on, and keep the plastic from sucking quite flat to the platen and blocking the holes right around the mold.)

For larger molds, you may need taller spacers, about the thickness of nickels. Tall molds trap more air under the "tent" of plastic that you create when you stretch the plastic under the mold, and taller spacers allow more air can to flow under the mold in the crucial first second. If the gap between your mold and the platen is too big, though, the plastic may suck in around the edge of your mold and need to be cut off. A combination of windowscreen and penny-sized spacers usually works well.

Weird coincidence: i was playing with a proper vacuum former today!!

Sweetness! +rep

Hell Yea! Looks preddy easy to make to. +Rep
I have a shop vac, and a oven.

Now I just need to find something worth vacuum forming. Hummn..
Maybe a fun weekend project. :think:

You really should give a credit line to each post if you did not write the post. Name, link, etc.

Quote:

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Originally Posted by Crimson Sky

You really should give a credit line to each post if you did not write the post. Name, link, etc.

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oh yeah sorry i'll put a link up now :up: Thanks