To build the vacuum form, first two "picture frames" are needed. These are constructed out of 1x4 wood. I cut out four pieces 16" long, and four pieces 7" long (size can vary; a bigger frame will allow bigger parts to be made, but if the part is smaller, there will be a lot of plastic waste). I then made two crude picture frames (both the same size), using the metal "L" brackets to hold the frame's four pieces of wood together (the outside dimensions were 16" by 11.75"). Attach the "L" brackets towards the outside edges of the picture frame (you'll see why in a moment). After it was done, I put the non-metal sides of the picture frame on a belt sander to make them as flat as possible.

Keep in mind that most household 30" ovens have an inside dimension of 18" by 21". So don't make your jig bigger than that.

Now that the two picture frames are made, lay them on top of each other, with the metal brackets on the "outside" (the bare wood faces touching each other). Then drill six 3/16" holes through both frames (one in the middle of each short side, and two evenly spaced on the long sides). Now six 2" bolts and wing nuts can be put through the frames to keep them clamped together.

Now place the clamped together pictures frames on the two foot square, 1/4" thick fiberboard, at the edge of one side (the outside edge of the picture frame aligns with the outside edge of the fiberboard). Take a Sharpie pen and trace the inside of the picture frame on the fiberboard. Remove the picture frames and set them aside. Next drill a hole the same size as the shop vac hose through the fiber board (my shop vac hose was 1 1/4" outside diameter). Position the hole just inside the blue sharpie picture frame tracing, on the side closest to the edge of the board.

Finally put two layers of the foam adhesive weather stripping on the outside of the drawn blue line on the fiberboard. Put one layer right on the outside of the line, and put the second layer around the first layer (not on top of the first layer!) You have now made a vacuum form jig!

Have a (Plastic) Drink on Me.
The next trick is to find a plastic that can be used for vacuum forming. It needs to come in sheets, and to be somewhat flexible. The original space craft was made with polystyrene. I tried that material, and it's just not durable enough, as it rips and tears easily. I tried ABS plastic. Though tough as nails, it doesn't vacuum form very well, and it's hard to keep it at the right temperature without self-destructing. Can't use plexiglass, as it shatters to easily. Can't use Lexan, as it bubbles too easily when heated. The last plastic I tried was PETG. This was the ideal plastic!

PETG is the same material Williams and Pinball Inc. uses on 1990s pinball ramps and flat plastics (though sometimes Pinball Inc uses CAB, see below for details on that). Now I know, you're gonna tell me about your Star Trek Next Generation pinball where the ramps are all blown out, and how that plastic flat slignshot plastics are all chipped. But think about it. You're constantly beating this material with a 1 1/16" steel ball, and it's basically holding up pretty good.

PETG is extruded Polyethleneterephtalate Glycol copolyester sheet. It has close to the durability and impact resistance of polycarbonates (Lexan) with lower cost, and is easier to work with. PETG, like acrylic plexiglass, offers a visually clear product that compares to optical glass. Yet PETG has greater impact resistance than acrylic. Minor surface scratches can be removed with heat (have you ever seen the blow torch trick used to remove scratches in pinball ramps in the "This Old Pinball" videos?) When fabricating with PETG, it can be bent with heat and the edges can be flame polished.

PETG is also part of the PET family of plastics. There is considerable similarity between the three PET products (PET, PETF, and PETG). Plain polyethylene terephthalate (PET) or polyester is most commonly associated with a material from which cloth and high-performance clothing are produced (e.g., DuPont Dacron polyester fiber). PET is also the material used for soft drink bottles (recyle symbol number 1) and many other molded consumer product containers. Increasingly over the last ten years PET has gained acceptance as a material of choice for beverage bottles. Cleaned, recycled PET flakes and pellets are in great demand for spinning fiber for carpet yarns and producing fiberfill and geotextiles. PETG, where the "G" represents glycol modifiers, which are incorporated to minimize brittleness and premature aging. This polymer is used in applications where thermoformability (heat forming) is required. Polyester film (PETF), is another PET derivative, and is a semi-crystalline film. PETF is used in many applications such as videotape, high quality packaging, professional photographic printing, X-ray film, floppy disks, etc. The film's primary advantages are high thermal stability and mechanical strength. In fact, PETF has one-third the tensile strength of steel (have you ever seen the Tom Hanks movie "Cast Away", and what he does with video tape?)

Features of PETG:

• Outstanding toughness, not brittle.
• Easily trimmed with a router or power saw.
• Edges can be flamed polished and buffed to high gloss.
• Low forming temperatures 280 to 320 degrees F.
• Available in a wide variety of thickness' and colors from .020 to .500".
• Will reproduce mold surface finish to the point of replicating wood grain mold surface.
• Chemically resistant to most cleaners.
• Decorates easily with spray paint, hot stamping and screen printing.
• Vacuum forming only needs 14 PSI (Pounds per Square Inch).
• Draft angles of 5 to 7 degrees for ease of part removal from mold.
• Cost is fairly low at about $1.60 sq/ft.

So PETG is the plastic to use. The only downside to PETG is the fact it is not UV resistant (which means it can yellow from UV light). Note the last two bullets. It vacuum forms at only 14 PSI (Pounds per Square Inch). That's good, because just about any decent shop vac can suck that hard. But the last point is an important one. The "draft angle" is the overall angle of the mold. That is, the top of the mold must be narrower than the bottom (a somewhat pyramid shape). This is required, otherwise the newly formed part can be difficult to remove from the mold! This is no problem with the Space Pilot craft though, as the sides are slightly angled like a pyramid.

The only other plastic I could have used was Cellulose Acetate Butyrate (CAB, or A.K.A. "Butyrate"). Unlike other common synthetic plastics, the cellulosic plastics like CAB are not manufactured by polymerizing a monomer. Instead, they are produced by the chemical modification of cellulose, a natural polymer. CAB is characterized by good strength, toughness, and high surface gloss. In addition, it has good clarity, sparkle, and will take paint or screen printing readily. Pinball Inc. explains they use CAB in ramp parts that they have difficult details like lips and small crevasses, or in ramps that are tinted (like Addams Family and Twilight Zone, as PETG requires a special color order and would be cost prohibitive). CAB is slightly more flexible than PETG, and the mold distribution is better with CAB, as it forms to the mold with less "stretching." Although CAB is adversely affected by alcohol, alkalis, paint removers, and acetones, it is resistant to most household chemicals. Additionally, CAB is resistant to ultra-violet radiation (that is, it won't yellow easily). CAB applications include cellophane, Rayon (carpet fibers), tool handles, panels for illuminated signs, steering wheels, goggles, bathroom fittings, decorative trim for cars and consumer durables, drawing stencils, pens, and blister packaging amoung others. Cost is about 30% more than PETG, and because of this, I did not use or try CAB. Expense is probably the main reason Williams did not use it either for its plastics.

So I went to the local plastics store and bought a 4 foot by 4 foot sheet of .060" thick clear PETG. Cost was about $25. I cut the large sheet into smaller 13"x9" pieces, and put a cut piece between my newly made picture frames, and clamped it down with the bolts and wing nuts.

The Coin-Op Cook: Baking Plastic (Yummy).
Put the kitchen oven on "bake", and set the temperature to 325 degrees. As the oven warmed up, cleaned out the shop vacuum, dumping it's dusty junk into a large plastic bag. Also clean the internal vacuum filter. These are important steps, as the "suck" on the shop vac will be dramatically increased if the vacuum is clean.

Now moved everything to the kitchen, close to the oven. Put the fiberboard jig on the edge of the counter top, with the 1 1/4" hole hanging over the edge of the counter. Put the shop vac hose into the 1 1/4" hole, and secure it with a piece of duct tape. Test the weather stripping seal by putting the picture frame with installed flat PETG on the weather stripping, and turning the vacuum on. The PETG should suck down tightly against the press board, and should not leak. Cleaned the mold (space craft) of any dust (compressed air or the shop vac works well for this), as any dirt or particles could get imbedded into the PETG plastic. Also clean the flat PETG plastic itself, and make sure the blue protective film on the new PETG plastic is removed.

Now put a 1/2" high wood block in the middle of the Sharpied picture frame area on the fiber board (this is an important step and it can not be skipped!) Put some double sided tape on the bottom of my mold, and placed it on top of the wood block (note the wood block should have a smaller footprint than the space craft mold) in the center of the picture frame. Note this step can not be skipped; the mold must be raised up with a block. Also the mold should not obstruct the shop vac hole in the fiberboard.

Just incase there is a 'plastic accident' and you warm the plastic too long, it's not a bad idea to put a layer of tin foil over the oven rack. Makes cleanup a lot easier if the plastics gets on anything, and the wife won't yell at you. The oven can then be warmed up to 325 degrees (again use the "bake" cycle in the oven, so only the lower burner turns on).

Open the oven and put two 8" long pieces of 2x4 wood in the oven, and put the picture frame with the PETG plastic installed on the 2x4s. Turn the oven light on, and close the oven door, watching the plastic through the oven door window. Hopefully when you do this you didn't make your picture frame larger than the oven!

As the plastic starts to warm up, it can warp and get a slightly wavy shape. Don't worry about this, it means the plastic isn't consistently soft yet. As the plastic warms up it will flatten. It took about two minutes, and then the plastic started to sag in the middle (the 2x4 blocks allowed the plastic to sag without touching the metal oven rack below it). I let it sag until it was about 3" beneath the picture frames. Be careful, don't let it sag too much! Because once it hits a certain sag point, it will sag really fast until there is a big hole in the plastic where the sag once was, and a gooey mess all over your oven! Also if the plastic gets too hot, it will develop small air bubbles. Experience is the best teacher here, so have enough PETG plastic to play with.

Notice how the plastic has "drooped" below the wood frame due to the oven's heat. Now is the time to remove the frame from the oven, and get it quickly to the vacuum form.

Using gloves, open the oven and quickly move the picture frame to the vacuum form jig. Press the picture frame squarely over the mold and on top of the weather stripping. Make sure you push the picture frame straight down squarely on the mold, otherwise you'll stretch one side of the plastic more than the other, making the plastic thinner on one side. Once the frame is squarely down, immediately turn the shop vacuum on!

Here the warm soft PETG is placed over the vacuum form with the space craft mold. The vacuum is turned on, and the soft warm plastic is sucked down all around the mold.

If everything has gone fast and good, as soon as the shop vac comes on, the soft PETG plastic will suck down over the space craft mold. If one side didn't lay down right, I used a plastic pen to gently push the plastic down. While the vacuum was sucking, I used a heat gun to warm up any sections of the PETG that didn't form well over the mold. This kept the PETG soft and easier for the vac to suck down, especially after the PETG had cooled from the vacuum (just turning the shop vac on cools the plastic fast, so the heat gun helps a lot).

Right after turning on the vacuum, I also take a heat gun and warm stubborn areas of the plastic that don't want to "sit down" easily on top of the mold.

After about 60 seconds turn off the shop vac. The PETG plastic should have formed nicely over the mold. On two occassions I was unhappy with the results of my vacuum form (I had not cleaned out the shop vac before starting, so there wasn't enough "suck"). Instead of throwing away the already used plastic, I just reheated it in to the oven and tried again (this assumes you can get the mold cleanly out of the newly formed plastic without any cutting). This actually worked quite nice, allowing me to not waste plastic that didn't form right over the mold.

After you're happy with the newly formed plastic, undo the wing nuts and remove the PETG from the wood picture frames. Also remove the double sided taped wood from under the mold. Now the excess plastic around the mold can be trimmed with a new razor blade. Any plastic that hooked underneath the mold needs to be cut away, so the mold can be easily removed.

The underside of the PETG after it is vacuum formed and before the mold has been removed.

The next task was to remove the body filler mold from the PETG. This is why we embedded the "T" nut inside the mold. Just screw a bolt into the bottom of the mold's "T" nut, put the bolt in a vice, and pull the PETG off the mold. This is difficult to do without the bolt, because there is no way to hold the mold while pulling off the newly formed PETG. After the PETG was released from the mold, a belt sander was used to make the bottom of the new space craft perfectly flat. A Dremel tool was also used to cut any holes or slots in the space craft's body.

Once you have the rhythm down, you can make one plastic part about every 10 minutes, mass-production style. Make thousands of them and give them away at parties. Seriously you'll find making parts is actually very fun and rewarding, even if you don't know what to do with all the PETG parts you're making!

I forgot to put the T-nut in this mold, so a 1/4-20 tap was used instead.
Moral: don't forget the T-nut!

Sanding the bottom of the new part flat on a belt sander.

Painted Me White.
Since the PETG was clear, this gave an ideal painting situation. I could paint the *inside* of the body, instead of the outside. The color will shine through the clear plastic and look great. Also the paint would be nearly impossible to scratch during game play since it's on the inside. And finally you don't have to be a perfect painter to make the body look great (runs won't show). Any overspray on the outside of the body can be removed with alcohol. I used Krylon paint and it worked great. I decided to go with white, as the space craft in the game's flyer was white. This also makes the craft's decals stand out better (I tried blue like the body I borrowed, but it just didn't look as good).

The original Space Pilot body is at the top center.

Decals.
Speaking of decals, they also needed to be reproduced. The space craft's body had two American flags, two "USA NASA" decals, two side pilot decals, and a front windshield decal. Surprisingly, this was really pretty easy to make. Using the computer, I just scanned the original decals off the original space craft body. I imported them to PhotoShop, and cleaned up the graphics (these edited graphics are available at marvin3m.com/arcade/spacpil.htm). Next I went to www.decalpaper.com and bought some clear water-transfer inkjet printer paper, and printed the decals on this paper (white is also available, which would have been good if I used a blue space craft). After printing I clear coated the decal paper with a wet coat of Krylon Crystal Clear (otherwise the inkjet ink would bleed from the decals when wet) and let it dry overnight. They also make decal paper for laser printers, and that does not require the clearcoating step.

Now that the decals were printed and the body was dry, I put some warm water in a small bowl, and added a couple of drops of white Elmers glue to the water (this will help the decals stick better). Then I cut the decals out and placed them one at a time in the small bowl of water. After about 15 seconds in the water the decals easily slide off their paper backing, and were put on the new space craft. Tap dry them slightly with a paper towel to remove excess water. They looked great! I let the decals dry for an hour.

Now the new space craft body was complete. I installed it in the game, and it worked like a champ! I was rather impressed with myself. The new PETG body will be way more durable than the original thin polystyrene body. And frankly, it looked way better than the original too!

Conclusion.
So was all this work worth it? Well sure! I mean I mastered some new skills (vacuum forming plastic and making decals).

Sidebar: Vacuum Forming 1990s Parts.

Ok so you like the neato vacuum forming technique used on the 1968 Space Pilot. But you're not into these old EM machines (you're a 1990s pingeek). So how does this apply to you?

There are number of parts that can be vacuumed formed for 1990s machines. Several that really come to mind are the "Boulder Dash" mountain in White Water, the "Hover Ship" in Terminator 2, and the lower ball arch guns for Cactus Canyon. All of these plastics are easily damaged, and none are readily available.

Here's how I remade the hover ship for T2. The original plastic is .020" styrene, and rips and breaks very easily. So it was an ideal canidate for recreation. Just like the Space Pilot's craft, I put masking tape all around the edge of an unbroken T2 hover craft, and filled it with Bondo body filler. I also made sure I embedded a 1/4" T-nut into the wet body filler. After the body filler was partially dry, I removed the original hover craft body.

Next I sanded the bottom of the hover craft mold smooth, and fixed any imperfections in the body filler using Super Glue. When I was happy with the mold, I put it on my vacuum form fixture, and made some PETG impressions.

Overall the new hover craft body came out pretty good. Though my recreation doesn't have all the detail of the original (not enough vacuum "suck"), the new body is way more durable than the original. Another problem I had was making my body "chrome". The original chrome finish on the T2 hover craft is hard to duplicate. I tried Krylon Chrome metal spray paints, but that didn't look quite right. I mean it worked, but it was not a perfect color match. But overall the finished hover craft came out pretty good, especially if you don't have one!