Tag Archives: plastic

Vacuum Formed Balustrades

June 19, 2013 Eric Hart

One of the first projects I worked on when arriving in Santa Fe was actually for a scenic element. One of the shows has a number of decorative balustrades way upstage, and they wanted to vacuum form them. I was tasked with turning the wooden master.

The first step was gluing up a number of poplar boards. This was going to be a fairly thick piece. I made two, so I could split them down the middle and give them four halves to vacuum form on a single sheet of plastic.

The lathe in our props shop has a duplicater set up. This allows you to cut out the profile of what you want to turn in a thin sheet of plexiglas, and the blade can follow that shape. You still need to finish it up by hand to make sharp corners and smooth it out, but it helps keep your shapes and sizes consistent across multiple pieces.

Above are the two balustrades, ready to go!

Next I had to split them directly in half. Luckily, we have a massive bandsaw, and I could build an oversized dowel-splitting jig to cut the whole baluster in half in one pass.

The next step included a new technique for me. I had to drill holes throughout the wooden mold for the vacuum to pull air through, paying particular attention to the undercuts. They also asked me to mount the molds on a sheet of plywood with a gap underneath, and drill holes all along the periphery. Since the vacuum form platen only has holes at regularly-spaced intervals, it would not suck the plastic tight against the bottom of the mold; this technique was like creating a custom platen to sit on top of the regular platen.

That was actually the end of my part. The scenery department took my molds and began running them through the vacuum former. I don’t have any pictures of that, but I do have a video of the machine in action. Above is a photo of the resulting pieces as they get mounted to the scenic piece.

How-to

Spiritual Stones from Legend of Zelda

May 20, 2013 Eric Hart

Here are the last of my Legend of Zelda props I made last month for a local theatre group. I previously posted about the Master Sword, and some rupees; you can find out more about this project in general at those links if you are interested.

The last prop, which is actually three items, are the spiritual stones. These are various colored gems in gold settings. They have names, too: Kokiri’s Emerald, Goron’s Ruby, Zora’s Sapphire.

As with the rupees, I cut the shape of the stone out of a piece of wood, vacuum formed two halves out of acrylic, and glued them together (painting the inside before gluing, of course).

Layout of Goron's Ruby — Layout of Goron’s Ruby

Starting with Goron’s Ruby, I used some reference images from the video game itself to lay out a full scale drawing of the stone’s setting onto some 3/4″ MDF.

I made most of the cuts on the table saw (my nifty cross-cutting jig lets me safely cut arbitrary angles on small pieces). The bevels were also cut on the table saw with the blade set at an angle.

Since the emerald had a sort of “wrap around” design, I cut the pieces individually and glued them on one at a time to achieve an exact fit. It was a bit tricky getting all the angles right, but it gave the nicest result.

Because the shape of the sapphire is trilaterally symmetrical, I used my compass and bevel gauge to make sure all three parts were drawn the same.

It had to be cut out with the jigsaw and cleaned up by hand with files. Some further shaping was done with the Dremel.

Once finished, the pieces just needed to be primed and painted. The emerald was painted with the stone already attached. For the others, I painted the settings first, and then the stones were glued in (so I didn’t have to mask anything).

Of course, it always helps to take cool photographs of your props. One day, I’ll get around to posting a quick tutorial on photography.

Tools

Using a Big Boy Vacuum Former

May 8, 2013 Eric Hart 1 Comment

I have been working at the Santa Fe Opera for a few weeks now. While I haven’t completed anything enough to show on this blog yet, I did shoot the video below. I needed to vacuum form a giant champagne bottle which I turned in foam on the lathe (actually, half of the champagne).

The Opera has a large vacuum former capable of taking full 4′ by 8′ sheets of plastic; even cooler is that the whole thing was built by the technical director, Eric Moore. This video shows me pulling a sheet of thin styrene over my form.

How-to

Rupees from Legend of Zelda

April 24, 2013 Eric Hart

For the last few weeks before I came out to Santa Fe, I was building some props for a local theatre group known as The League of Extraordinary Thespians. They are doing a musical of The Legend of Zelda: Ocarina of Time. The first props I finished were the rupees, which are a type of jewel used in the game to buy items (some of you may have already seen these in an Instructable I posted last week. Sorry).

I figured the best way to make a translucent gem was to vacuum form the shape. You remember my ultra-cheap vacuum former, correct? Before I could use that, I would need a form. I decided to do the front and back of each rupee separately, and then glue them together. So first, I would need to cut a piece of wood into a rupee shape.

You can see I’m using the (oddly-named) GRR-Ripper from Micro-Jig; it makes accurate cuts on tiny pieces in a safe and straight-forward manner. I did all the cuts with my table saw, giving me a pretty clean-looking rupee half.

I got a sheet of clear acrylic from Hobby Lobby. They only had it in one thickness; I’m not sure what it is exactly, but it’s less than 1/16″. I started vacuum forming the halves and trimming them out, leaving exactly what you see above.

Before gluing the halves together, I painted the insides. This way, the paint would never wear off, no matter how much the actors handled them.

For the green ones, I tried watering down acrylic paint. It was pretty tricky, since the paint kept wanting to bead up. Normally, you would lightly sand the surface of the plastic to help the paint adhere better, but that would kind of kill the “translucency” effect. So I bit the bullet and bought some blue and red spray paint so I could just lightly dust the other rupees.

I used a solvent-based glue (Amazing Goop) to glue the halves together. The glue was a bit thick and dried flexible, which helped make a stronger bond since the edges didn’t quite match up exactly.

And that is how you make a rupee!

Useful Sites

Beware the Sites of March

March 15, 2013 Eric Hart

This post is a few years old, but interesting nonetheless. Art Direction, Props and Authenticity talks about the importance of realism in prop making, specifically the realism of a prop’sÂ weight. A prop that appears too light can take the audience out of the moment.

Game of Thrones has a new video out showing some of the work that goes into their props. It features prop masterÂ Gordon Fitzgerald, some drawings of props, and a look at how the smallest details are taken care of.

The Make Magazine blog featured a cool tip for usingÂ polycaprolactone plastic to make sanding blocksÂ (they use Shapelock, though Friendly Plastic is another familiar brand name). If you need your sanding block to have a different shape for fitting around a curve or other odd surface, just heat it up in boiling water and reshape it to what you need.

Finally, if you have the time (about a half an hour), here is a good video featuring Adam Savage as he weathers and ages a prop. He articulates his process rather well, even though a lot of the process is carried out by instinct and intuition:

Prop Agenda