Topic: Making new cases

As discussed on a thread in the hardware "plastic housing" making a new injection molded plastic case for the Chumby is expensive, in the range of $20,000 or more.

Two solutions were proposed, first 3D printing on Z Corp printers. This can be done for about $300-400 per part. It requires 3D CAD drawings. For $300 you only get one part, but the part will be accurate to the drawings. This is a good way to check parts before sending them somewhere like Protomold is a $20K solution but you can get a 1000 parts if you need them.

The second proposal was to use a thermal plastic like Polymorph, Friendly Plastic or Shapelock (all the same thing, $30).  But to make an accurate case with Polymorph you need a mold.

Example of free form part making with Shapelock: … -projects/

Comments indicate that "RTV Silicone putty for mold making" would be a good choice for a mold.

While Googling around for Silicone putty I found this guy who is really into mold making and who happens to be in San Diego., John Greer, 4401 Twain Ave. #26, San Diego, CA 92120,  (877)342-8860

Maybe a local Chumbian can give him a visit and get recommendations on good ways to do case mods. For example it would be very helpful to buy a prebuilt mold that had the inside half of the mold already configured to hold the Chumby hardware and the outside half was customizable.

Re: Making new cases

Thanks for posting the info here Jon!

If in doubt when making...make MAKE your first stop... (maybe they should hire me!)

They suggest Shapelock...links to a good tutorial (same as Jon's above) and the company's site... … our_h.html

How to work with liquid ABS plastic... … astic.html

How to set up your own 3D plastics factory at home... … odels.html

How to make a DIY Vacuformer for making molds... … ormer.html

Keep digging and I am sure there will be many other articles/links of interests...

A non-plastic option would be to use polymer clay like Sculpey...very do-able at home. Resin is another option.

Here is an Australian supplier of Friendly Plastic...there are a few other possible options listed on this page too. … inting.htm

Another idea is to hunt down a local craftsperson who works specifically in plastics. I happen to be doing a workshop with just such a person in December, so I will pick her brains and report back here then. She happens to work in both recycled and new plastics and is apparently a fount of knowledge on the subject smile

Here is a bit of an example of what I am talking about from the non-industrial, craft/art perspective

Re: Making new cases

Not sure if this might help with the mold-making...I've never really thought about how this all could relate to plastics as I generally work in sterling silver...but they might work with some creative thinking...

If you scroll down you will see a link to the MSDS...

You could also look here...these are products used for jewellery mold-making.

And here...apparently some of the designer toy makers get stuff here...

Some great tutorials on molding and casting...

A place for supplies...and some really good how-tos...they sell liquid plastics...probably worth exploring... this company looks like they could be really helpful...very DIY/beginner oriented but professional too.

Please let me know of any successes, further thoughts, experiences...I'm interested in having a play with some of this stuff myself...perhaps I could use it to clone myself so I could actually have time to get to all my overdue craft projects!!!