Vacuum Forming At Home

A little dumpster-diving let [Nick Skvarla] build his vacuum form machine for around $5. He pulled a vacuum cleaner out of the trash, which was tossed away because of a broken power plug. He put it into a box which had been sealed with spray foam and used a piece of pegboard for the top side of the enclosure. He takes a piece of 40 mil PETG plastic from the hobby shop and mounts it in a wooden frame. That goes into the oven on broil until the entire sheet is sagging, then onto the vacuum former. Above he’s making forms out of some figurines which he’ll walk you through in the video after the break.

There’s a whole world of manufacturing processes that use these forms as a starting point. What would you use this for?

50 thoughts on “Vacuum Forming At Home

  1. @Calculon: I used that video as a starting point, but all the designs I found used a shopvac for the suction which just seemed cumbersome. I had a lot of scrap lumber around and had found the broken vac and pegboard in a dumpster, so I decided to make my own design.

    @Munden: I found the sheeting at a craft store. Apparently it’s used a lot in model railroads and RC car bodies. I would like to find larger/cheaper sheets, but haven’t looked much yet.

  2. You should experiment with covering holes that are not needed/used with duct tape to get a better vacuum. I walked through a shop that made golf carts using this process. They used a Shop-Vac for ten foot square sheets. They used the duct tape to cover holes that weren’t needed. I am sure that your little vacuum is up to the job. Also, the holes they had drilled in the mold were very small, like 1/16th.

  3. My father was really big into vacuum forming when he was young, said they were building whole bodies for RC vehicles, electronics enclosures, etc.

    Seems like it is kind of a lost art, everyone is so into extruded plastic reprap style construction that they ignore something simple enough you can do in the kitchen without any complex equipment.

  4. That is great, Nick, I like it. I have been wanting a vacuum form for a while, not sure what I would do with it, but it could be fun.

    I have watched a few videos of home vac-forms and the thing that sticks out to me is the glaring need for a knee or foot switch. Everyone seems to have a moment where they must take their hand off the plastic frame to hit the switch and it just seems there is an easier, more stable way to do it. Just a thought.

    1. haha the switches on professional machines are insanely cumbersome. I prefer this diy way, plus can just hit the switch of my vacuum cleaner with my foot (as its designed for that).

  5. You could print master object(s) on your 3-d printer or carve them on your CNC mill then create negative molds with the vacuum former.

    Use the resulting mold to cast copies in wax/plaster/silicone/sugru/soap/frosting/chocolate/etc…

  6. Team this with a foam chunk, hot knife, moldable plastic beads nd hot water… welcome to the cheapest way to custome build any chassis piece. And subsequently WORLD DOMINATION!!!

  7. “You could print master object(s) on your 3-d printer or carve them on your CNC mill then create negative molds with the vacuum former.

    Use the resulting mold to cast copies in wax/plaster/silicone/sugru/soap/frosting/chocolate/etc…”

    I immediately thought of using this for chocolate molds. Say good-bye to those expensive Wilton molds….

  8. I just started doing this with a very similar setup… just a cookie tin with holes poked in it and some other minor mods.

    A good plastic to use if you don’t need a clear finished piece is HDPE – commonly found in my house in the form of milk jugs or bottles of windshield wiper fluid. Heat it until it turns clear and starts to sag, and you’re ready to go!

  9. I’ve not done vacuum forming nor I have project going on that could use it, but I’ve had this idea for some time now that this could be useful in mold making for fiberglass/cf parts.
    More in detail: make a plug (the model, positive mold) out of something that’s easy to work with (wood) or use existing item, then vacuum forming thin (if very detailed) plastic over it, and adding structural materials on top of the plastic while it is still on top of the plug. Anyone done this?

    Maybe not the best method for large quantity production but I just thought it might be quicker way to make a mold for dozen or so parts.

  10. That’s very cool. I’ve run a vacuum former for making custom chocolate molds for “Executive Novelties and Marketing”. Shit for the PHB’s. We made our plugs from cherry wood, with a slight bevel on the edges, and drilled very small holes in any internal corners to evacuate any trapped air. Before I would use the plug, I would wipe it down with PAM, or some other food-safe oil/lubricant.

    @JA: I don’t think a vacuum former actually pulls a high enough, or consistent enough, vacuum for doing composite layups, and usually the plug is coated with PVA wax for a release agent. The techniques are similar, but the equipment requirements are different. The vacuum former needs high airflow/low vacuum. The bag press for composites needs low airflow/high vacuum.

  11. I hate when people throw perfectly repairable machines to the thrash. (The vacuum cleaner)This shows when one doesn’t own the device. If you can’t open it, its not yours.

  12. Not sure why this comment didn’t show up? Refreshed and waited a bit – sorry if it is a duplicate!

    As to suppliers:

    Onlinemetals, McMaster and USPlastics will have the materials you are looking for at decent (but not rock bottom) prices.

    Your local plastics supplier (look online) in full 48″ x 96″ (or larger) sheets will likely be the best price. For thin material, they can roll it up for you and ship it in a tube form through UPS (freight charges start at $100 and go up and up from there with liftgate delivery).

    Keep in mind that you can only use thermoplastics for this application (not thermoset). Think Polypropylene, Polyethylene (HDPE, LDPE), Acrylic (not Lexan, which is polycarbonate), and the like.

  13. this is a nice little setup for vacuum forming small parts and doodads. i’d really like to build a large one (2x4ish) with an included heat source. hmm… maybe an arduino controller for it…

  14. I recently read that some of the home vacuum formers were using a cheap electric skillet as a heat source. Apparently they provide a fairly wide heat pattern and are easy to find at any Target or WalMart for under $20.

    Electric skillets also seem to be a tool of choice for other hardware hacks so many of the circuits you may want to add have already been written about in great detail.

  15. This is freakin cool. If you don’t have a 3d printer you could make something out of layers of thick paper or cardboard glued together and then vacuum form it… though you can’t do all the same things or get the same accuracy, it’s still freakin cool.

    Oh also, the storm trooper outfits themselves were vacuum formed, not made from vacuum formed molds.

  16. I wonder if you could form you own speaker cones for some DIY audio stuff?

    Full size traffic cone reproductions. (For VLC fans)

    -and of course making custom packing/shipping containers for valuable or fragile items.

    Very resourceful hack!

  17. @rallen71366

    I didn’t say anything about making a fg/cf part with vacuum former. That wouldn’t work. I was talking about making the mold for the part.

    Why I thought of vacuum forming? Because the mold is as (or more) tedious to make as the part itself. And the top surface of the negative mold is usually gel coat (before wax and pva) so swapping this to plastic shouldn’t be a problem.

    Oh well. I just have to try it when doing some fg/cf work. Whenever that is.

  18. I tore apart three toaster ovens for the heating elements, for my version of this (no transport of hot plastic, just slide the mold tray down over form), I even put a momentary O/I switch on the base to activate the vacuum. Also used a bit of an old air hockey table instead of peg board so the little divots in the plastic are smaller. I’m thinking of using screen as a base for the next version tough.

  19. Second the comment about getting plastic sheet from a plastics supply store. Buying the Evergreen stuff from your local hobby store is a VERY expensive way to acquire sheet. I bought some large sheets of styrene in various thicknesses for my scratchbuilding projects and the price was quite good.

  20. I’m thinking of trying this but to use and electric quartz space heater as the heat source above the vacuum form.

    As for plastic sources: Our local hardware store carries a full line of plastic sheets (clear, white translucent) that I’ve tested quickly with a lighter for malleability. I wonder is a local sign shop would part with some also…

    This will be a great way to produce lightweight identical pieces for models.

  21. thermoformed by vacuum lexan is the primary way to make rc cars bodies… cutthroughstuffguy get your fact straight sometimes…. or call tamiya and kyosho to tell them they are doing it wrong…

  22. @CutThroughStuffGuy – Polycarbonate is a thermoplastic too, you just need to get it about a hundred degrees C hotter than PMMA (acrylic glass). We’ve done some hot bending of lexan for FIRST robotics, worked fine, should work okay for this, just a bit more heat involved. Might require hotter than an oven, might not.

  23. I worked in a theatrical scene shop for a few years. Our vacuum former was handmade by a former shop employee. It takes 4×8 sheets of plastic, and we would drill 1/16″ holes in the model. The plastic was suspended in a frame between oven-heating elements and the model; the plastic in the middle would sag about 18″ down. Drop the frame and boom, you have vacuum molded whatever. It is a phenomenal tool! We were making shells of logs; the plastic shell was tacked to the walls and painted to look like a cabin. The detail was good enough that it looked like real painted wood from about 5 feet away. And someone made it in their garage! I don’t know where they found the vacuum pump though: it weighed about 500 lbs.

  24. I wonder if a discarded home vacuum would be strong enough to achieve vacuum compression on food. Seal-a-Meal-like machines will seal food, but won’t compress it like commercial vacuum sealers, so the home chef is limited in what transformations he can perform on food.

  25. I would suggest using a regenerative blower for this if you are going to go big. Something with low pressure, high flow. Think shop-vac vs vacuum pump only with a much higher duty cycle and lots more “suck”.

    You can pull close to 30 inches of mercury with these things. Shop-vacs start to crap out at about 3.5 or 4 inches.

  26. How detailed can these get? I was thinking of making some copies of sprues of warhammer 40k figures, if it could be detailed enough this could be a great way to save a ton of money on building these figurines.

  27. Agreed, it is a nice way of vacuum forming but with the help of infrared heaters and vacuum cleaner, vacuum forming can be done at home easily and that will be better than any other way. Infrared heaters will provide you an option to use thick plastic sheets.

  28. This is so cool , I would like to make molds to cast resin. Does anyone know what type of plastic sheet I can use? I also would like to find a tutroial on how to make my own vacuum forming machine.

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