RE: invesment casting from desktop printers

From: Tom Richards (
Date: Fri Mar 03 2000 - 10:31:11 EET

Alex: We've found Sanders to be the only RP process which can produce small
to tiny intricate parts accurately with good finish all-around. We've been
running our machine for seven years. Yes, it's been upgraded over the years
under service contract. It now runs quite reliably, albeit slowly.
Tom Richards, Metallurgist

At 09:50 AM 3/2/00 -0500, you wrote:
>This is an interesting customer relations approach...
>I'm beginning to see the light... now I understand why Al Hastbacka
>responded the way he did back in mid January.
>Does Sanders not like criticism or competitors?
>I guess if you can make a machine that can build .0005" layers (as I read in
>Rapid Prototyping Report Vol10, N2, Feb 2000 page 6) then you can afford to
>loose a few customers because your machine is so great that everyone wants
>Thanks for the info Karl.
>-----Original Message-----
>From: Rolf Hubert []
>Sent: Wednesday, March 01, 2000 9:22 PM
>Subject: RE: invesment casting from desktop printers
>Karl, you bought these 2 machines knowing how precise but slow these systems
>are. Our machine is not for everyone especially you. I have heard nothing
>from you that makes any sense. Why don't you do yourself a favor and sell
>it to someone who would appreciate them. We have delivered over 400 machines
>and very few customers have problems like you.
>Our machines are for dimensionally accurate, smooth, small parts. We build
>turbine blades that you couldn't even begin to do with other systems. Why
>don't you try stopping the verbal abuse. You bought systems that frankly
>you shouldn't have, shame on you.
>I can't even imagine why you built a model that took 650 hours, at least it
>Rolf Hubert
>Industry Marketing Consultant
>Sanders Prototype, Inc.
>-----Original Message-----
>From: []On Behalf Of
>Sent: Wednesday, March 01, 2000 2:55 PM
>Subject: RE: invesment casting from desktop printers
>We have investment cast from all of the machines that you listed including
>the Sanders machine. Regarding the "Concept or Desktop" modelers, These
>machines are ok for products that do not require very tight tolerances. In
>general we have found that the parts on these machines are typically blocky
>with little or no detail and have no thin wall features. This is not to say
>that the equipment can not build these features but that they may not
>survive the gating or dipping processes. We have a Genisys in-house and
>have yet to cast anything from this machine as the build quality is less
>then desirable for one of our cast parts. The equipment sits idle for 90%
>of the year and the other 10% it is running crude small scale mockups. We
>have cast parts run on the Z-Corp and Actua(ThermoJet) equipment and for
>blocky parts they are ok although the surface finish on the Z-Corp was a bit
>rough at best! We have 2 Sanders machines in-house (an MM6 Pro and MMII) and
>although the bladed products we build on these machines are small (about the
>size of your thumb nail) it took about 630 hours of machine time to complete
>enough blades to make one completed ring(3 rings of blades per engine)!
>These machines are headed for soon!
>We also have 2 SLA-500s and with these machines have had the most success in
>the casting arena! As an example on one build I had 500 parts run in less
>then 2 hours and in a week they had been cast, cleaned and installed in
>engines! Despite the frustration with support removal and having to seal
>QuickCast patterns this is, in my humble opinion, the best route to
>prototype investment castings. We are now enjoying nearly a 100% success
>rate with patterns generated on the SLA equipment.
>Beyond the specific RP equipment when generating a pattern for investment
>casting you have to consider several factors that may prevent the part(s)
>form completing. All of which should be considered even when using
>conventional wax patterns. The longer I am involved in this industry the
>more I realize just how much of a black art this process is! There are no
>standards regarding gating, burnout, shell materials, and thickness,
>preheat, melting temperature and pouring temperature! We have tried
>solidification models and flow analysis and have found that our best first
>guess is as accurate as the results from the analysis.
>I'm sure this is much more then you needed but one can not give a simple
>answer with out a minimal amount of background. I hope this helps!
>Karl Denton
>Lead Engineer
>Williams International
> -----Original Message-----
> From: Kevin Dyer []
> Sent: Wednesday, March 01, 2000 12:31 PM
> To:
> Subject: invesment casting from desktop printers
> Hello
> I would be interested in hearing from others who have used
>ThermoJet, Z
> Corp or Genisys systems to produce investment castings. This
> would be helpful in preparing for an upcoming presentation that
> these technologies with 'industrial strength' RP systems like SLA.
>If you
> have anything you would like to share it would be appreciated.
> Kevin Dyer
> InterPRO Rapid Technologies
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