We have for some years used cad-cam milled wax masters for our work
in cast silver, gold and platinum. We have the master milled then do
a fair bit of hand work on the wax before casting - these are usually
one offs or two offs (cufflinks) After seeing some impressive results
at a trade fair of what a wax printing rapid protype machine could do
we decided to give it a try as the waxes seemed much finer (no tool
lines) and very accurate. Unfortunately they did not cast well at
all. The wax used in these machines must be of a different
composition and was breaking down during casting (we lost one wax
altogether) so we ended up with castings that needed far more work
than if we had done them the original way. I just wondered if anyone
else had had similar experiences?
Andrew
Hello
There must be something wrong with casting process. Maybe the wax
needs a longer burn out time with a more gradual increase in
temperature. If it is one of the main brands of printer then there
should be no problem. I have had many waxes done through various
sources without problems. Start from beginning to end and reveiw all
prcoesses to check for likely cause.
Phil
any possibility of you posting some pictures of the results you are
speaking of would be of great help - goo
The output material for perfactory machines such as EnvisionTec is a
very tough laser-cured superpolymer that does not burn well. The
thermal expansion of the model as the oven ramps really weakens the
investment and special burnout procedures, and sometimes materials,
are necessary. It is for this reason that we switched to the new
"hybrid" material for our customers’ RPs- part wax, part polymer.
The wax melts out at lower temperatures, leaving a matrix of polymer
that does not expand strongly enough to damage the investment. I
would gladly grow something in this material for you if you’d like
to try it. Otherwise, for RPs you want to go straight to cast I’d
recommend a Solidscape grown model.
On a related note, if you ever have trouble manufacturing a CAD
created piece, I would gladly take a look at your file for you to
help overcome any casting trouble.
Jason
Casting House