EZ vacuumform machine . . .

[Lambo003]

I checked through the HT's and FAQ's and didn't find anything on how to make a home made vacuum form. So here's my take on it! I made this for under $25 bucks.

The key here is to shop around for the parts, as prices seem to range from astronomical to dirt-cheap. The frame rails can be had for pennies on the dollar if you shop when these items are out or going out of season.

What you'll need.

Pre-Punched IC-Spacing Perfboard, Project Box 4.5X8X2.5 - Radio Shack

Aluminum Screen frame, Screen Spline (gasket) to fit the frame channel, Misc. Bolts and wing nuts, Nylon Frame connectors - Home Depot (Etc.)

Attacking the project box!

First you will need to drill a hole in the side to accept the size hose that is with your vacuum source. This varies from manufacturer and it's best to start the hole small, then work your way up to the correct diameter for a nice tight fit. You want it to fit fairly snug to keep the vacuum source strong and be able to hold the connecting end it's self with out it slipping out. The hole seen here was cut small then enlarged to size with sandpaper, testing the fit along the way.

Next, cut the perfboard to fit and sand the corners round to match your project box. Keep things as tight as you can and the end product should drop right in place. Reinforcements glued to the inside of the box help support the perfboard once it's under pressure from the vacuum. You may find you need to beef these up as you use the vacuum-form machine over time. Once the reinforcements are in place, you can now attach your perfboard using the screws that came with the project box. If you would like, you can run a bead of silicone caulk around the edge of the box and perfboard to add to the overall suction from your vacuum.

The Frames

You will want to cut the frame sections so the final pieces are slightly larger than the project box. Mine are about a half an inch larger (as seen in the pics). You will need to cut enough material to make two frames (an upper and a lower). Keep the sizes as exact as you can. Now you can assemble the frames using the nylon corner connectors. Once these are finished, put them together and clamp them so they do not slip apart. Carefully drill through the nylon corners with a drill bit the same size as the bolts you will be using. The one's pictured are 1/8 " X 1" bolts with wing-nuts.

Once the frames are complete, you will need to insert a strip of styrene inside the spline channel. This will raise the spline up just enough to act as a gripping gasket to hold your plastic sheet goods in place. If you do not do this, the sheet plastic will simply slip out between the frames when you heat the plastic or when you go to actually vacuum form parts and ruin your efforts. Glue both into the channels using either epoxy or a hot glue gun.

Vacuum Forming

Practice, practice, practice.

Each time you use this machine you will most likely find different techniques that work best for you. A few that I have learned over the years are:

Use an electric source for heating your plastic. Gas stoves just won't work here.

Locate your vacuum form machine close to your heating source. I usually place it on one half of the stovetop and heat with the other.

Clamp your vacuum hoses down firmly! Once you kick on the suction, the hose naturally wants to coil up and drag your vacuum form machine along with it! Duct Tape works really well for doing this.

Getting enough suction to a specific area can be tricky. I sometimes place plastic wrap around the item I'm vacuum forming and leave about a 1/4-inch space around it. This concentrates the suction to a specific area and leaves you with a nice crisp finished piece with no voids.

You can probably see in the pics that the frames have indentations in them. This is where I use a set of clamping piers to act as a handle keeping my hand away from the heat source. Remember this process involves high heat and can and will burn you so, use caution while handling heated materials!

I use Plastructs butyrate sheets or K&S sheets specifically for windows and such. The styrene sheets tend to be a bit brittle for my taste. Regular white Evergreen styrene sheets work great for body parts and other small details.

As seen in the pics, the sheets are cut to fit the frames and the corners are trimmed to fit around the corner bolts. The sheet extends into the frame at all sides trapping it in between the frame gaskets.

Heating Plastic

Start your heat off on a medium setting. You will be surprised how easily plastic melts! Keep the frame above your heat source and slowly lower it down to about 7 or 8 inches above the stove element. You will see the plastic start to change and become very glossy. Hold it there just until the plastic starts to sag a bit. Just as fast as it heats up, plastic also cool rapidly. You want to work in a steady pace from heating to the actual vacuum forming. You should have your vacuum source running the entire time through out the process. Again, once the plastic sheet starts to sag and becomes glossy, in a quick but steady movement, move the frame over the buck and onto the surface of your project box. If all went well, the vacuum will suck the air out beneath and draw the hot plastic down and around the item you're vacuum forming. Give it just a few seconds (and I mean JUST a few) and switch your vacuum source off. Let the piece sit for a minute to cool.

Bucks and such

What can you use for creating items to vacuum form? ANYTHING! I use a lot of resin, Plaster of Paris, 5-minute epoxies . . . and the list goes on! I've used parts from die-cast cars where no other part was available in plastic form. I build a lot of 1/43rd-scale cars that use vacuum-formed windows and the first thing I do when I receive the kit is make copies of the originals. I just pour plaster or resin into the original, let it dry and pop in out! This also lets me make any refinements to the parts of they don't fit correctly or have any defects in them. Resin allows you to sand and polish out any bubbles or flaws in the original master giving you a near perfect piece!

There are techniques such as drilling your master in certain places to take advantage of the process. Let's say you have a sharp corner or an under-cut. Small holes drilled next to these, then opened up on the back of the master will concentrate suction to these areas. At the time of writing this I couldn't find any of the masters I have used. When I come across them I will add pics of those too.

During a conversion of an Diablo SE Jota, no plastic kits were available. Maisto however had a nice diescast. I chopped the engine cover off and vacuumformed over the diecast piece. Saved me a ton of time in scratchbuilding!

Here, Alezan's Lambo Portofino windows were horrible with huge 1/8 inch gaps in the rear window. I made a resin buck from the original vac formed windows and then added styrene strips to each side of the casting. After careful sanding and polishing, I was able to vacuum form a new rear window that fit perfectly!

Hope this is useful to some of you and if you have any question, please feel free to email me.

Again, use caution and common sense.

[cinqster]

Lambo,

I've made a similar box using 1/2" pine but I've not used it yet. Why is gas a no-no for heating the plastic? Most of the website howto's I found suggested using a gas oven?

Nice tutorial BTW!

[freakray]

Nice how to, thanks for taking the time to add this one.

[Lambo003]

I've used both and with gas you run the risk of over heating the plastic or ending up bubbling the plastic all together.

Electric just seems much more forgiving and you have less of a tendency to over heat not only the plastic but, the nylon corners and frames themselves.

Originally Posted by cinqster

Lambo,

I've made a similar box using 1/2" pine but I've not used it yet. Why is gas a no-no for heating the plastic? Most of the website howto's I found suggested using a gas oven?

Nice tutorial BTW!

[white97ex]

great tutorial. hopefully this will end up in the how to section. the perf board...is that electronics board from radioshack?

[Lambo003]

Yup, that's it!

Works pretty well for this application but, I wish it were a bit thicker. When under pressure from the vac it bows down which is why I used reinforcements along the sides of the box.

Originally Posted by white97ex

great tutorial. hopefully this will end up in the how to section. the perf board...is that electronics board from radioshack?

[freakray]

Originally Posted by white97ex

hopefully this will end up in the how to section.

Done

[mike@af]

Definately need to build one of these. I wonder how well a hair dryer, heat gun, or heat lamp would work.

[Murray Kish]

Thanks for the info. Nicely written and illustrated!

Murray

[Lambo003]

Thanks for the comments guys!

Not sure that any of the mentioned would generate enough heat to do an effective job, with the exception of the heat gun. But hey, anything's worth a try!

Originally Posted by GTmike400

Definately need to build one of these. I wonder how well a hair dryer, heat gun, or heat lamp would work.

[RallyRaider]

Kudos! Now we just need to see are some examples of parts vacformed with this beastie.

[Martin S]

Interesting!
What do you use as vacuum source?
Does a regular vacuum cleaner work ?

[cinqster]

Originally Posted by Lambo003

I've used both and with gas you run the risk of over heating the plastic or ending up bubbling the plastic all together.

Electric just seems much more forgiving and you have less of a tendency to over heat not only the plastic but, the nylon corners and frames themselves.

Cheers Lambo...I'll experiment with both when I get round to it,

John S.

[cinqster]

Jus for future reference for anyne wishing to make one - it worth putting a strengthening web across the middle of the box. I couldn't get the large size perf board so I used two boards joined together over the web.

Remember to drill out the centre web to get even suction through the box!

Originally Posted by Lambo003

Yup, that's it!

Works pretty well for this application but, I wish it were a bit thicker. When under pressure from the vac it bows down which is why I used reinforcements along the sides of the box.

[cinqster]

Most websites recommend using a heady duty shop vac, but I've designed mine around a normal household cleaner - just hope it works?

I adapted one of the weirdo (never used) tools that came with our cleaner - glued it straight into the box so the hose is a perfect fit.

Originally Posted by Martin S

Interesting!
What do you use as vacuum source?
Does a regular vacuum cleaner work ?