Cast a copy of a scratch built model

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kugar13
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Cast a copy of a scratch built model

Post by kugar13 »

Hey guys!

I'm working on a project with a few people. One of the guys is making a scratch built ship for the project that we want to make duplicates of.

Instead of making multiple copies by hand we'd like to cast molds for identical duplicates. I've been doing some research and was wondering what you guys would suggest.

I don't think casting a solid mold made of resin is the most economical means to make duplicates. What would you guys suggest? Breaking the prototype down into pieces and cast them separately?

Thanks for the help guys!
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Chacal
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Post by Chacal »

To give you guys useful advice, we need to know how the model is, and how big it is. Does it have a lot of greeblies onto its surface? Is it angular or curvy? Does it have sub-parts, like the Enterprise (saucer, engineering, nacelles) or the Galactica (main hull, outrigger hangars)? Is it like a Star Destroyer (basically a single piece, with add-ons)? Or is it like the Jupiter II or C57-D, a one-piece deal?
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Post by kitty »

And other things, like: are you going to do pressurecasting. Will you make the molds yourself (quite an art as i discovered) an so much more.
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kugar13
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Details

Post by kugar13 »

Oh, sorry about that. I'm new to this.

The prototype will be made out of Styrene materials. The model is based on an original concept, but the scale is in the 1/35 range. I'd say no bigger than your typical x-wing 1/35 scale fighter, but thicker. It has two main wings with a few other protruding fins. All holes will be filled with putty for the casting process. It's being made modular, so it doesn't have to be one solid piece when cast, which is good because I don't believe the wings would allow it to case as a single piece. The biggest hurdle in my opinion is casting the main body as one solid piece, which we may not do. I'd prefer to make the model (positive) from the cast (negative) in resin.

I'd say the exterior of the model is smooth. It has one main wing section with 4 other fins, think tails. Has 2 engines built into the tail. An exterior cockpit. I guess you could say the main body is built like a boat with a corvette hood. I know that sounds ugly, but it isn't. We're still designing the prototype, so I don't have a picture at the moment.

Does anyone make casts/molds of their models?

Does this help?

Thank you!
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Joseph Osborn
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Post by Joseph Osborn »

Bring it over to me and I'll cast it for you :)

Seriously, the assembly has to be broken into manageable sections that will come out of rubber molds with the least amount of difficulty. I suggest you do some research on the subject to get a feel for the tasks and the workflow. Here's an article on this very site:
http://www.starshipmodeler.com/projects/jw_resin.htm

Google can help you find other tutorials and resources. Have fun!
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Post by TER-OR »

You'll want to break the model down into parts to do your casting. The model you describe is proabably too big to do in one mold.

http://www.smooth-on.com/
This has a lot of references. There's also a forum here on SSM about resin and molding.

You may want to ask in the Construction forum.
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Post by Sparky »

Blappy did a handout ofr 2005 wonderfest class on mastering for casting....

http://www.starshipmodeler.info/wfest2k ... ut2005.pdf

hollow casting can be done by hand for short production runs, and saves both on resin and life of the mold (thicker resin gets very hot)

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<a href="http://www.kc6sye.com/2_wheresaneatpart.jpg" target="_Sparky">Is this plastic thingy on the counter a neat part?</a> <a href="http://www.kc6sye.com/1_casting_inprogress.jpg" target="_Sparky">Let's cast it.</a>
kugar13
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Post by kugar13 »

Thanks guys, you are super awesome for helping me out!

I know the road ahead will be frustrating, but I can't help being excited about it! All of these articles are getting me pumped!

Thanks!
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LindaSmile
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Post by LindaSmile »

There's a whole forum full of ideas here:

viewforum.php?f=15
Is this plastic thingy on the counter a model part or can I throw it away?
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