Re: Injection Mold needed for Jewelry

From: Paul Finelt (
Date: Mon Aug 23 1999 - 00:49:27 EEST

Keltool works fine when you have a master or an original that is oversize.

If you are trying to fit mating parts (stones, coins, jump rings,etc.) ,
you need to consider all the shrinkages ( original mold shrink, plastic
shrink and investment casting shrink -- investment and solidification).

If you don't have a master, Keltool can't produce one for you.

Paul F.

At 01:11 AM 8/22/99 -0400, wrote:
>Ricky ;
>I've been watching the responses on the RP-ML to you inquiry and I'm
>supprised no one suggested to you 3D Keltool. At my facility we do cavities
>for things like small toys and gadgets literally by the thousands. Alot of
>these toys have intricate detail as well as undercuts all over the place. We
>have found 3D Keltool to give better replication than any other process
>available today (even deadly beyliium copper). We work with either hand
>carved or CAD generated masters. If you have the actual piece you would like
>duplicated into an injection mold it is no problem to do. The only setback is
>the 3D Keltool process has a shrinkage of .006 per inch. This means if your
>original piece was 1 inches across. The 3D Keltool cavity will be .994. This
>is not considering the plastic shrinkage either. If your final part is molded
>in ABS which has a shrink of .006 per inch. The final molded part will
>measure about 988. If this is not a problem we can probably cast your
>cavities without you having to go through the frustration and expense of
>redrawing everything in CAD. The cost if the cav and core blocks are about
>2x2x1 inches would be $500 each for the cavity and core. The amount of
>complexity doesn't change the price (the more complex the better). If we have
>to generate the parting lines it will cost about $150 extra if a flat parting
>line, or $300 if complex. Delivery is about 10 days. If there are undercuts
>in the part this is no problem for the 3D keltool however if they are severe
>you will only be able to mold softer plastics in the mold once its done.
>Otherwise the parts won't come out of the mold. You might be able to still
>mold your part even with the undercuts if you float the center section of the
>mold (where the medalian goes). We would have to look at the part to give any
>real answers.
> We have 9 moldshops in USA and Sweden but unfortunatly they are all
>totally booked up and we wouldn't be able to build a mold for you at this
>time. But we certainly could supply the 3D Keltool cavities to you. You could
>have your local neighborhood tool shop fit it into a moldbase. This normally
>takes about 20-30 hours of labour drilling the ejector pin holes and EDMing
>the parting lines and such. Actually we are in the process of buying another
>small 12 man mold shop right near you ( in Texas). If things go well in a
>couple months we could possibly send you there.
>Good Luck
>Bob Morton
>Fusion Engineering
>For more information about the rp-ml, see


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