Picture of Vacuum Former
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This is my first version of a vacuum former and if you skip to the last stem you see why I needed to make some changes. The new version is here Vacuum Former 2

A vacuum forming machine is used form plastic sheet into the shape of a mold. Vacuum forming is used extensively in industry to make all kinds of plastic products. For this instructable I'll so you how to make a vacuum form machine and I hope to do more instructables on things you can make with this machine. If you don't know what a vacuum former is and want to know how it works PLEASE READ THIS BEFORE CONTINUING. My machine is not be exactly like the one on the link but the principle is the same.

Step 1: Get the Parts

Picture of Get the Parts
This is a basic list of most of the materials I used to put together the machine and a few of the tools I used.

1. Nichrome wire
2. Hardibacker cement board
3. ceramic standoffs
4. aluminum flashing 14in. wide
5. 1x3in. Wood stud
6. wood screws assorted lengths
7. 8-32 machine screws
8. 14 gauge stranded wire
9. screw terminal block
10. crimp-on connectors
11. 1/4in. thick plywood

Control Box
1. 4 gang electrical box
2. 4 600watt dimmer switches
3. 4 dials (radio shack)
4. 14 gauge stranded wire
5. wire nuts
6. extension cord with one bare wire end

1. 1/2x3/16in. Balsa Wood
2. 1/4in.Thick Plywood
3. Wood Glue
4. 2x4 Wood stud

1. 1x2 wood stud
2. Two Hinges
3. Two Sash Locks
4. Two 6in. Angle Brackets

1. Jig saw
2. Miter box saw
3. Hack saw
4. Utility knife
5. Wire cutter/stripper
6. Mulitmeter
7. Drill

This is the prototype machine I built before I built the real thing. It used one heated in an all aluminum oven. This is an over/under design, the oven over the platen. My machine will be a flip type machine because the oven and platen are at the same level and the frame flips between them.
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Lotus141 year ago
I don't see how the heating elements are made, or I should say, it would be nice if there was a drawing with dimensions and materials so you could copy your design. The calculations could be done to vary your basic design, but a starting point would be useful.
kewrw282 years ago
Practice will make perfect. Dont give up now!
Brianaala4 years ago
Great instructable! A couple of other people have commented that the heat source being underneath the plastic will give you the potential of fire (as you found out) but I would like to add a little more on that. Another benefit you get from having the heaters above the plastic is that 1) the sag can go further which helps if you are pulling heavier guage stuff or tougher stuff like plexi and 2) when styrene first sags from the heat (in the overhead heater formers) it will sag a long way then it will pull up a little as the heat affects the other side of the styrene, this is usually the best time to get a pull because the material is at the perfect blend of strength and pliability. Having said all that, your design is very cool and it will work great for the home hobbyist!
hey guys can someone tell me where the pdf for the "wiring" is? I can't seem to find it anywhere... all I found were pictures of the oven. Can someone draw or explain how to wire these dimmer switches from the outlet and to the terminal block??? Thanks!
rsingh34 years ago
Anyone know of any projects i can do with mr coffee coffee makers? I recently bought a bunch off of http://coffeemakersmrcoffee.com and need to find uses for them. Thanks!
hmmm.... you should try using a heat gun for your heat source. its a bit slower but no flames
With a heating gun you won't be able to get even enough heat for the whole sheet. The easiest and best way is actually to have your heater placed directly abouve the table upside downso that the sheet gets heated from above and away from the coils not closer to the coils. You're gonna have to mount your sheet frame on rails, but it's a much safer approach to vacuum forming.
ss30004 years ago
Good job and nice build. I worked for a company that made items by vacum forming (Sailing Specialties Inc) a few years ago working in the CNC department. First suggestion, stop using styrene, styrene is a light weight plastic that is not very good for heating amd forming. If possible try to PVC, ABS, or even lexan. They are much better suited to heating and forming. Number two, instead of the hinged tray that flips make a tray that slides like a drawer. Which takes me to the third. Instead of the heating elements on the bottom, place them on top, or better yet elements top and bottom with metal plated for heat spreaders (they would also cover the elements and should prevent fire and make clean up easier.
mikesnyd4 years ago
Like you said. it sags and then touch's the element. An easy solution to a even and uniform heat is to have say a hotplate with lid that covers all you have. Thus heating from the top down to your styrene. So it is basically a box where your styrene is the bottom and small venting around its perimeter. I have seen a few guys using the top element in the oven. And you can notice when the plastic(styrene) is ready due to the mat finish it receives from heat. If you have at least a 1000W vacuum it will help pull a bit better if it happens to be to the cooler side of readiness. Man vacuum forming is fun. i feel like i am running a sweat shop some days.
jiganto4 years ago
I think some sort of heat spreader mounted over the heaters would give you more even heating and prevent melting plastic from falling onto the heaters and catching fire. Maybe a sheet of aluminum or thin steel.
EGSMachine5 years ago
you get a x10 in XP for the humble pie you just ate. thanks for sharing!
Quite agree! "There are no experimental failures - there's just more data..." If I might suggest: Masonite for the platen/vacuum manifold - hard and smoooooth surface, can be had in both solid and perfboard, tolerates heat pretty well, less work, greater hole-pattern precision at, probably, slightly greater expense... Also, some kind of heat-resistant "honeycomb" separator atop the elements would keep the sheet from sagging into the "free-fire-zone" when it goes too floppy, too fast like that.
bulwynkl5 years ago
I like that while doing your first test and having it catch on fire that you still took the time out to photograph it!! I've always wanted one of theses and now I have a basic design... have you considered using IR lamps instead of the wire heater?
trouble015 years ago
We needed a video from your work please add a video !!!
you know, i think you could have still salvaged this design. Perhaps you could have moved the oven to the top, burners down like you did, but have it roll to one side w/ cabinet rollers or something. That way, you can have your fire safety deal, and even more so, because you could roll the heat aside if it did catch fire. You could also perhaps put some clear acrylic to hold up the plastic-frame-holder thing, so the heat would still stay in (not sure if that's desirable in this application) and you could still see the plastic sag. but then again, perhaps flipping the plastic would ruin it. idk.
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additionally, this would take up a lot of space. More than your new design, but i think it's still simpler.
sturmey5 years ago
Very cool idea. I like how you hinged the material holder to make the switch from heater to vacuum plate easy. I may borrow this idea for some of my projects.

Also, congratulations on a successful test of your fire suppression system. I hope your next test goes better.
Spokehedz5 years ago
Oh wow... That took guts to post your epic fail. Bravo.
alcurb5 years ago
Great project. I would like to see the conclusion. I'd like to suggest to use a chicken wire screen over the heating elements so that the plastic melts, it will drape over screen instead of the elements. You can always cut another piece of chicken wire screening, if the first one proves impossible to clean.
jegner25 years ago
vist www.tk560.com/vactable4.html there you will see something similar, based on Thurston James' machine.
GM20096 years ago
I want to build something similar but will use Quartz heaters from small oven. Backerboard is nice but the problem is that is to big in my opinion to buy. You use only one portion of it and have big leftover. It is bulky to transport to and not so easy to cut. Another solution is to make your own concrete boards with concrete mixed with sand and fiber (search 'concrete board' here). That way you can make any size you want. You can also make one piece shell (in steps). This method has its own benefits. When mixture is poured, wooden pegs can be added for screw holes. I think that Vacuum Former Design 2 is better than this one. Most industrial formers are done with heater above (plastic sagging and melting problem). I've made few of my own forming machines and none was as good as I wanted. Forming is simple, but I have to repeat few key points for success: -Good uniform heater. Working with kitchen oven is fine for tests but for good results good custom made oven is needed. -Good plastic holder frame. Has to be robust and accurate, otherwise vacuum will not be achieved. I always add strips of 150 Al sand paper around to hold plastic better. -Good and accurate frame sliders. It is important that frame with heated plastic be transferred to vacuum plate quickly and accurately. -Good vacuum plate. Having good seal is even more important than vacuum source. Vacuum cleaner can produce enough of vacuum for forming but only if there is a good seal. High end vacuum pumps will help if finest detail is needed (but only if all above is achieved).
fleazy4216 years ago
a circular saw with fine blade is the best for thin strips just make sure to setup a fan to blow the dust away
vernonstien6 years ago
OOOPS, Awsome, I thnk yoou did a good job for your first time!
vernonstien6 years ago
vernonstien6 years ago
So far so good, could figure the Wattage of the burners from ohm's law. can I make a suggestion? Don't use a fan to help heat the material, it blows the sag and makes it wavey that causes imperfections in the part when it pulls. If youwant to use a fan, use it to help cool the part after your pull time is done. I rettro fitted a former at work, changed the the heat source from "cow rods" to inferred ovens, added a PLC for the controls, and wished I would have made the material move over the heat source instead. It came out fine, been wanting to make one for home to tinker with, I have a heat source and that's about it....
vernonstien6 years ago
I'm with you so far......
jpatano6 years ago
I'm building something VERY similar to what you have here, and i have a question about the nichrome wire mounting... what are you using there to isolate the wire from the frame of the box ? does it matter if it's metallic, or conductive ? i guess being pretty conductive, most metals wouldn't alter the resistance factor too badly, so it shouldn't affect your heat output... i'm just curious as to whether you could possibly short the system out.
Doug Costlow (author)  jpatano6 years ago
The wire I had came mounted in the x-shaped ceramic mount. I've seen other guys use ceramic stand-offs. I would not use anything conductive, the chances of some thing being shorted would be to high. Your dealing with many amps of current you need to be as safe as possible.
ahh ok, thanks for the quick reply! i couldn't tell from the pic if that "X" shaped mount was metallic or not. i was planning on using some sort or ceramic insulator... anyone here know anything about using plaster for such an application? i've heard of people using it for lower temp installations, and if i can't use it on this, I have another project that is low temp ( <200 degrees F ). You did a good job on this project though, looking forward to seeing your final design!
Doug Costlow (author)  jpatano6 years ago
My final design is on instructables too http://www.instructables.com/id/Vacuum-Former-2/
deanlol6 years ago
Does anyone know how to make something enclosed? Everything on these types of vacuum formers have a 3d front and no back. I want to make something that has a 3d front and 3d back with a seam along the side. I know I'm not explaining very well, but the first thing that comes to mind is hollow plastic toys with a seam on the side and a small hole in the bottom. I'm trying to figure out how to make plastic pink flamingo's that can be staked in a yard.
Doug Costlow (author)  deanlol6 years ago
Toys that you see with a seam and a hole are injection molded. Those machines are much more complicated than a vacuum former. If you need two sides you could make two molds, one for each side, then vacuum form them and stick them together.
What gauge wire did you use for the burners?
slim_jim7 years ago
Finally! An intellegent, useful instructable. Lots of useful detail. Nice work!
he must be a new member, ha ha
slimguy3797 years ago
whats a good site to get polystyrene? and are there any substitutes? I need a few 12" X 12" sheets. hopefully cheap
Eclecticos7 years ago
I would recommend heating your styrene plastic in the oven until it sags instead of building a stove. Would have liked to se a better seal around the base. Good Instructable none the less.
ydeardorff7 years ago
do you have a layout for the nichrome wiring for a 24 by 24 inch oven? I could use that. Im trying to source up prefabbed heating coils, but if I cant Im going to have to build my own oven. I could use some help with this, its my only hurdle on this build
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