I am a CNC operator, assembler, and installer for a foam shapes company. We have been making movie props, themed environments, and architectural features for 30 years. AMA

Hi, I'm an engineering student, so I got some technical questions for you (or your colleague respectively):

• What CNC-machines are you using, can you name a brand, post some pictures, etc. ?
• What are the max. dimensions you can manufacture in one piece?
• What material is the foam, or do you use different sorts?
• What cutting tools are you using for the foam and what's the max. cutting velocity?

Thanks!

I'm not permitted to name brands or exact limitations - however, I can reveal that we use 1 lb, 1.5 lb, and 2 lb EPS respectively. Hot-wire cutting velocity depends on the density of the foam, the detail of the shape, and the temperature of the wire. Our machines are big enough to cut multiple 10 foot blocks simultaneously in one piece.

[deleted]

Someone asked about stress working with the movie industry and what other movies and shows we've done, and then deleted their question, hope this answers it : Always, the show must go on and production deadlines must be met. We made cannons for Gods and Generals, columns for the Manchurian Candidate, stone features for the castle in Black Knight, vents for MIB III, and an old cemetery in the woods for O Brother, Where Art Thou. We also did the architectural trim for the series Revolution, sand castle sculptures for The Glades, and a tombstone for Matlock. Just to name a few of probably thousands.

What would you most like to create as your next project- if you could pick?

The high buoyancy of foam makes me want to make a houseboat out of it powered by solar panels...everyone I tell that to looks at me as if I'm crazy.

do you guys air brush the foams? how is it painted?

also, do you make comfortable living? how is the outlook in the industry? I'm kind of curious in this field and wanted some opinions.

We make a wide variety of shapes with numerous finish options, depending on the needs of the customer. Paint and methods used varies from item to item. In some cases a sand or stucco finish is applied to the shape and then painted either by hand or with a spray gun. In other situations, we apply a 2-part polymer spray that hardens and seals the foam, prime it with a plastic-friendly paint, and then generally apply a latex paint by hand or spray.

I'm happy with my living now. Am I driving a luxery car or living in a 5000 square foot home? No. But, I love my job and it is very rewarding. Skilled CNC operators are in high demand so I'd say that there is a good future in this industry for anyone that is willing to learn and work hard.

What is the most well known movie in which your props have appeared? What specific item might we remember from that movie?

We have made quite a few props for TV shows and movies, one of the most noticeable being the giant bull from Year One. Pictures

What machines do you use? How many axis?

Can I have a job.

We have multiple axis CNC hot-wire and CNC router cutting machines. We're always looking for talented people.

How did you get into this job?

I started in finish carpentry 9 years ago and was hired here based on experience with tools and work history. I happen to be good with computers too, so when an opening for the CNC machines came up I jumped at the chance. Our engineer started working here while searching for a job in his particular field, he ended up staying and has made a lifetime career out of it.

I know it's going to vary a lot by size and detail, but what does pricing on these things look like? Is it accessible to consumers? e.g., a piece of headwear vs. a lifesize automobile.

What do you guys think about 3D printing? Do you worry that it will replace CNCs?

We've done a lot of shapes in the high-end residential industry and for small businesses - so, yes. However, pricing is probably prohibitive to the average consumer.

The size of most of our shapes are so big that 3D printing would not be practical where the technology currently stands. We've upgraded our machines many times over the years as technology has advanced and we plan on doing so as new and better ways of doing things emerge.

What's the largest project, and/or foam creation you've made?

The biggest thing I've worked on is WonderWorks, Orlando. It's a huge upside-down building that looks like it was uprooted and thrown onto another structure. We did all the foam shapes for the upside-down landscaping and broken-ground that goes around the top 3 sides of the building. Lots and lots of foam was cut, shaped, textured, and installed.

What kind of music do you make in your factory?

No music, although CNC routers make a loud screaching sound. Somewhat related, we made a 12ft statue of Hannah Montana once that was used for a radio station contest and then crushed by a bus. Found this video of the demolition: http://www.youtube.com/watch?v=a691l86LK4g You awesome redditors can probably find better footage.

I'm a current CNC operator with an engineering degree and this sounds like a very cool and challenging job.

With that being said, what is your biggest 'OH CRAP' moment while doing a project? As in throwing a tool and messing up a large part of the project or something along those lines.

I've been cutting multiple blocks at the same time and the wire was set at too fast of a velocity or the heat wasn't turned up high enough. In turn, snagging on the foam, breaking the wire, and messing up the shape. Definitely an "oh-crap" moment I've endured more than once. Like I've heard many craftsmen say: "Measure twice, cut once." Always check your settings before you cut.

Edit:...and then check them again.

Is CNC machining a young man's sport or can you start this at any age? Say 50?

We've had operators of all ages over the years. You need to be good with measurements and math, have an eye for 3D shapes, have basic computer proficiency, and be able to lift 50 lbs.

Would it be possible to make something like a themed environment for your own home or is the material too much of a fire hazard for residential use?

Foam is combustible, you would need to look at your local fire codes and take precautions. Regardless, it is widely used in interior applications where proper care is taken to install it away from possible sources of ignition.

I just bought a handheld wire cutter from FoamFactory...

Do you have any tips for working with EPS foam? What is your favorite solvent free adhesive?

Well, first, don't touch the wire while it's on. It will shock/burn the crap out of you. Second, make sure your wire is tight enough - if it is too loose your cuts will be warped. Third, find a temperature where the wire cuts the foam like a hot knife through butter. Not too hot as it will burn the foam which will look bad and not too cold or you'll be stretching it and it will leave lines in the foam.

And what about gluing together blocks of EPS? I was thinking a water based contact cement, or super 77 or 76?

(Edit: Replied too fast) I already learned the burning wire bit. Ouch. I'll make sure it's tight though, thanks for that!

lol, yeah it hurts. A polyurethane foam sealant (trying not to list brands) will do the trick as an adhesive - just don't try to cut through it as your wire will snag on it and burn the surrounding foam.

I remember you guys. I also went to Leesburg High.

I'm working with a summer intern that I'm helping where I can.

Would you have any recommendations on a 2-part expanding/tooling foam? Basically I'm helping him find options to build a male foam-master to take a fiberglass splash off of. Then layup a carbon body/fairing off of that.

This is for a university race-team.

Hey, sorry for the delay. For tooling - you would need an 8-12# density expanding foam. Trying not to list products on here, but seeing that you're from Leesburg: http://www.smooth-on.com/ should have what you need.

Thanks for the comment and best of luck.

I'm a sophomore at a Technical High School and I'm currently learning how to use CNC lathes and milling machines, and also the MasterCam program!

Excellent!