Re: DTM vs EOS

From: Elaine Hunt (Clemson  University), Lee Humphrey (Lockheed-Martin  Corporation), Michael Brindley, Stephen Rock (Rensselaer  Polytechnic Institute), Rob Connelly (Becton Dickinson  & Company)
To: RP-ML
Date: Wednesday, October 11, 1995
Subject: Re: DTM vs EOS
Ian,
     Maybe 1996 will be the year of lawsuit as vendors sort out who holds the RP
power.
     What about three desktop inkjet systems....who has the best patent
position???....
     Stereolithography......who holds the strongest patent??????
     LOM and Stratasys systems are not totally unchallenged.
     If you could right now buy any system in the world which would you buy and why?
Anyone brave enough to answer........Step up to the mic.
Elaine

Dear RPers
     I would by 3 different units each would have its own niche, 1st SLA500 
for size, casting patterns, surface finish and accuracy.  2nd would be 
Sanders, there again for size (small), accuracy, surface finish, 
portability, flexibility, simplicity, and castability and cost. 3rd 
machine would be the DTM mainly for direct metal, molds and tooling, 
also important is processing materials available like the glass filled 
Nylon.  
     As for US machines vs. European or Asian machines, familiarity, I go 
with what I know and I do not know much about their machines.  There may 
be many "right" answers out there.
     This is a personal opinion, not necessarily that of the company I work 
for, but it may be who knows.  
     This is not to put down the other manufacturers in the US.  They have 
good process also but for the primary needs that I have been involved 
with these are my choices.
Lee Humphrey
Lockheed Martin
Electronics & Missiles
Orlando, Florida
lee humphrey@ccmail.orl.mmc.com


Elaine Persall wrote:
> What about three desktop inkjet systems....who has the best patent position???....
Sorry to be picky, but ...
     HP and Canon own the desktop inkjet printer market.  They have a patent
cross-licensing agreement which allows them both to be in the business.
     In the Rapid Prototyping field, you are probably refering to the 
systems which shoot liquid droplets which solidify to build up a
3-dimensional part.  'Droplet deposition' is probably a better
description of these systems than 'inkjet'.  
     I can only think of two commercially available droplet deposition
systems:  Sanders and BPM.  The Masters patent covers the basic
process of building 3D objects via droplet deposition.  The last
I heard, BPM had a license from Masters, and Sanders did not.
When I talked to Roy Sanders and Al Metcalf about 2 years ago
at Dayton, they had patents pending.  Perhaps these patents 
cover an improvement over the Masters process - I don't know.
     There was also a US patent issued about 3 years ago covering using
a support material with droplet deposition. I heard about this
second hand, so I don't know the name or patent number on this.
     Melissa Orme's patent (I know of only one), covers only her 
method of droplet generation - it does not cover building objects.
     Well, that's my thumbnail description of what I know about patents
and droplet deposition RP machines.  I am not a legal expert, and
I am releying on my (admittedly imperfect) memory, so you should
check the facts if they are important to you.

> Stereolithography......who holds the strongest patent??????
     Well, 3D Systems has successfully defended their patents before.
I think Quadram (Quadrax?) got out of the business because of 3D's
legal action.  Isn't 3D currently involved in suing a company in
Germany (EOS, perhaps?)?.

> If you could right now buy any system in the world which would you buy and why?
     I want a Star Trek replicator! :)  :)  :)
  --> Mike Brindley   brindley@ece.orst.edu    Corvallis, Oregon, USA, Terra

Date: Wed, 11 Oct 1995 15:39:33 -0400
Mike Brindley wrote:
> There was also a US patent issued about 3 years ago covering using
> a support material with droplet deposition. I heard about this
> second hand, so I don't know the name or patent number on this.
     Perhaps this is US patent #5,260,009 granted Nov. 9, 1993 and titled
"System, Method, and Process for Making Three-dimensional Objects" by
S. Penn.  This patent was assigned to Texas Instruments, Inc.
     Does anyone know if this is being commercialized?  
-Steve
=====================================================================
Steve Rock                                          rocks@cat.rpi.edu

Date: Fri, 13 Oct 1995 09:10:53 -0400
Subject: What to Buy?
>If you could right now buy any system in the world which would you 
>buy and why?
>Anyone brave enough to answer........Step up to the mic.
     OK, i'm finally getting around to answering - so much for Rapid!
Well I don't think any of us has PERFECT knowledge of the real 
capabilities and pitfalls of all the systems out there.  All we can 
do is apply our engineering skills to evaluating each one's 
potential using as much information as possible.  Then we try to 
mesh that with our needs to come up with a best fit.
     At BD we have pretty homogeneous needs for prototyping injection 
molded plastic parts.  Very few metal parts are made, and the 
envelope is quite small - around 3 inches max for the most part.  
Given this situation, our SLA-250 has been a good fit.  The lack of 
z-axis accuracy is our only real problem with the geometry itself.  
What we do need, however, is complete functional testing of the 
molded parts - that Rapid Tooling stuff.
     Given that one need, I would (almost certainly will) buy a Sanders 
ModelMaker to create masters for tooling.  Here are the advantages 
that I see:  (1) potential for a factor of 10 to 20 times 
improvement in z-axis error (our toolmakers like to quote 0.0005" 
tolerances) (2) potential for smaller minimum radii in the drawing 
plane (0.002"?) and (3) potential for better as-built surface 
finish as well as easier finishing capability.  The slower building 
speed of the Sanders is not a big problem for us, since even our 
tooling components are pretty small.
     If anyone else knows of a way to get the above attributes, please 
share it with us.
     My two cents.
- Rob