Mold for molding Mendel corner parts 27$

Hi!

I ended up trying to mold the mendel plastic parts. I draw a mold and uploaded it to shapeways.com for ordering. Would there be any interest in this mold, if it ends ups a successfull way to produce mendel? The price will be about 27$ which you can, hopefully, use to produce all 6 corner vertexes? If this is successfull, I will make molds for the other parts as well.

You can see it in [www.shapeways.com]
Please, do not yet order it, unless you want to be an alfa tester. I have not yet tested it by myself.

I prepared the mold by importing the stl file from the reprap file system. Then I cut it to half (cannot mold a part with crossing holes. You need to be able to remove the piece from the mold..).
I build up a 2mm thick walls. The inner side is slightly sloped to make the removing easier.

My plan is either to order a packet of polymorph and mold it from that (Shapeways White & Strong can handle temperature up to 70 degrees) , or just by some resin and use it. I will inform you when I have some results.

Anyone have any experience on this subject? I think I need some releasing agent to be able to release the piece from the mold.
I'm considering honey wax (melting point 65 degrees), parafin (40-60 degrees) or stearin (72 degrees). So the polymorph melts at 60 degrees, the mold can stand up to 80 degrees (shapeways has updated the temp), Which releasing agent should I use? Should the agent be liquid (will it get mixed with polymorph) or solid when the mold is made?
My plan is first to melt the releasing agent (honey wax) and let it solidify to the mold. Then melt the polynmorph and let it cool down somewhere between 65 and 60.
Fill in the mold and let it cool down. Release the piece (hopefully it can be released..)
If I use parafin, it would be melted while polymorph is frozen, maybe the piece would be easier to release? Or would the parafin just mix up with the polymorph and spoil the piece?

Vaseline. Also, try [objects.reprap.org]
and do start a wiki page for the mold-piece if you like?

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

James might be the one to talk to, he is selling cast vertexs on Ebay.

The price has dropped from $40, to $35, now to $30.

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repraplogphase.blogspot.com

Shapeways can deliver in 10 days, regardless of the amount of orders (I suppose.) I have first going to test this, there is a lot of things that might not work.
btw, the price is lower, 27$ includes European VAT 22%, so the correct price would be around 23$.

In my experience, polymorph doesn't need a releaser. Depending on the mold material and the temperature, of course.

I've had success using it as it's own mold, without a releaser of any sort.

I have a hand-cranked wheat grinder, and also a fine gearmotor thing from an "omega juicer". I heated some up, wrapped it around the locking bits of the appropriate parts, cut them off and stuck them in the freezer. After a few minutes I pulled them out and stuffed more polymorph in. After Cutting the mold off (the parts where round, of course, but with bits sticking out that meant that I had to cut the molds I'd just made off) I simply held the new parts down partly in hot water to remelt them and stuck them together (being VERY carefull to get them aligned properly)

It worked great, and I got a very complex adapter part in about 30 minutes. I still have that part around somewhere. My wife's asked me about it just last week. Don't know exactly where it is though.

I've since reused the plastic the molds where made from for something else, of course.

Uhm.. Polymorph is the same thing as Shapelock, IIRC.

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I'm building it with Baling Wire

That's good news.. and with polymorph I can test easily; If it get stuck, it can be released by heating up to 60 (I suppose..).
Maybe we should continue this conversation here: [dev.forums.reprap.org]

Still waiting for the mold..

Actually, this seems to work, but but there are some tricks.. see [dev.forums.reprap.org]