material for building an LARGE size model

roadwarrior · Post by **roadwarrior** » Mon Oct 06, 2008 10:57 pm

Hi All,

Thinking about building a large-ish model (3-5 foot long), and was wondering what everyone reccommends for a hull material? Acrylic sheet, styrene sheet, wood? I have access to buy many different materials and adhesives, and equipment to machine it. Just need to decide about what material to use, and design around that.

Thank you for any input,
Tom

Lichtbringer · Post by **Lichtbringer** » Tue Oct 07, 2008 6:53 am

It depends from the shape of the object.

Kylwell · Post by **Kylwell** » Tue Oct 07, 2008 11:18 am

Depends on how you're going to light it, and how you're going to hang it.

And how long you want it to last.

Plywood, specially untreated & thin, delaminates over time if not proper sealed. In this day & age of LEDs and compact fluorescents you don't have to worry about heat build-up like the studio modelers do (or did). So you could easily go with schedule C pvc pipe as a frame & polycarb or acrylic sheet as bulkheads & sheeting. I prefer acrylic for it's stiffness but some like polycarb because it machines like butter.

Chacal · Post by **Chacal** » Tue Oct 07, 2008 7:15 pm

Kylwell makes a good point there: Don't follow the techniques used to build studio models if you want the model to last. The key to building a successful studio model is speed—you use what is easier/faster to build.

For a 'labor of love' type of model, do as Kylwell suggests, but I'd also chime in with: metal. A soldered tubular brass internal structure can support a lot of weight. Another thing: use good glue—2-part epoxy is best for long-lasting bonds. CA will eventually (a few years) crack and separate.

roadwarrior · Post by **roadwarrior** » Tue Oct 07, 2008 11:51 pm

Thank you for the replies.

The plan is to build a flying saucer with mandibles (!) and make it somewhat large. I was leaning towards acrylic because A) readily available in large sheets, B) cost effective, C) can be machined, thermo-formed and easily glued, and D) can be laser cut. And as access to the laser may be curtailed soon, I wanted to at least build a hull now and detail later.

I wanted to run thru other stuff as ideas as I know all of you here have vastly more of the stuff that constitutes knowledge in these matters than I. Build a model out of a box or do a minor kitbash and I'm good. This would be my first step into scratch (ignoring that 4 foot long cardboard stardestroyer I built sooo long ago).

If this gets off the ground, I'll post pics/info. Thank you for the input,
Tom

en'til Zog · Post by **en'til Zog** » Thu Oct 09, 2008 7:48 pm

I'd advise against using PVC pipe - at least the normal 'house plumbing' type. I was involved in a model build for a film and the guy in charge used PVC for the long, self supporting main spine with the mount in the middle of the 5 foot 2 inch long beast. Quickly, it began to sag. By the time it was finished, with moving 'arms' and all, it was sagging noticably.

Just my experience.

Kylwell · Post by **Kylwell** » Thu Oct 09, 2008 7:59 pm

en'til Zog wrote:I'd advise against using PVC pipe - at least the normal 'house plumbing' type. I was involved in a model build for a film and the guy in charge used PVC for the long, self supporting main spine with the mount in the middle of the 5 foot 2 inch long beast. Quickly, it began to sag. By the time it was finished, with moving 'arms' and all, it was sagging noticably.

Just my experience.

Sounds like too small a diameter. Larger the diameter the stiffer the tube.

Richard Baker · Post by **Richard Baker** » Thu Oct 09, 2008 10:02 pm

For a model thai size I would suggest starting off with a frame or skeleton- .080 aluminum if you can, threaded pipe or welded 1x1 square tubing would also work. It will give all the plexi a thing to hang on and support the weight when you display it. Tab and notch the plex when you can- it will help the epoxy hold things together.
It sounds like an interesting project you got there...

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