Counterpoint:
Ok so material costs are high compared to AL or Steel... But who fills
the Sinterstation chamber at 65% capacity and uses all that material
in one tool build? US$14,000 in metal equates to 437.5 lbs. of
RapidSteel. This is significantly more than the any size mold capable
of being grown in one build. Having recently completed a tool build
with cavity @7.5" x 4.3" x 3.8" @75% density weighed in @25#.
Assuming the core was the same size and grown at the same time that's
50#s or $1,600 @cost for material, possibly 4x QC7 or P-20. If you
expect to grow large molds with high Z heights you're asking for
trouble. The metal weight in powder upon itself, before polymer
infiltration, can cause deformations to the mold. A good and simple
example of this can be seen in the conformal cooling lines. If the 3D
mold CAD model does not leave sufficient wall thickness from the part
side to the cooling channel collapsing can occur. Experience and
recognition of the process limitations are an essential ingredient for
success. I've only addressed material issues!
Without addressing the other potential savings on bench labor, one
fact can be said today. DTM's process has opportunities to equal
other machining processes "based on its present state of the art".
Complex surface geometry (compound surfaces) are naturals for
consideration. Simple boxes or a high concentration of engineering
features/details (e.g.. AMP type connectors) are simply out of the
question "based on its present state of the art"
DTM has proved to be an excellent partner supplier. They continue to
add value. Since we've started our training Feb'97 for Rapidtool, DTM
has introduced one major technical improvement. This improved
accuracy and surface quality significantly. Additionally, they
continue to facilitate our process management as soon as we call
including sending their key people to help resolve problems. Our
largest hurdle in getting it right was our own inability to understand
the necessity for process management from the CAD model through the
finished tool. Only once was our success stifled by a DTM system
technical issue and never a mysterious material issue. The "state of
the art" continues to improve and the useful application of this
breakthrough technology is bright. My opinion as a user.
Ok so what's the shake out when it comes to overall costs compared to
other machining processes... DTM better not quite now! But 2-3x
conventional? That would tell me someone did not understand or cross
examine the marketing rhetoric with their own brain. DTM never and
still does not profess to be moldmakers. Why would any mold maker buy
into all that rhetoric. If in fact if it was true on one mold, how
the heck can you apply that as a general truth to all part
configurations?
I think the issue on selecting process is resource dependent. That is
what kinds of people and machines sit on your shop floor. We've
automated the machining processes significantly but they continue to
need skilled human intervention. All the processes need this. Where
is our diminishing resource. It's certainly not in machine
technology. If you are a moldmaker and hiring skilled people you'll
know this is the issue. Even those that are available have recognized
their marketability based on their knowledge. Sooooo their price tag
is going up.
Rapidtool from DTM was initially embraced by bureaus having the DTM
SLS process in house already. It may be they based their initial
Rapidtool buy decision on their successful experiences from rapid
prototyping and their market share. Tweak the machine, improve the
materials when all else fails put it on the bench to tune it in and
get right. We've continued to hammer the machine makers and the
material suppliers plus learned a few tricks of our own. Rapid
prototyping is better and gets better because there was commitment to
success and this meant you had to be a pioneer.
The DTM process is pure in concept. 3D CAD part model to 3D CAD mold
model to mold. No transfer process from pattern to rubber mold to
poured goop. No pattern to temporary mold to metal deposition to
backup system. Reduction of steps equals reduction of potential error
introduction.
Sorry for the editorial. But it seems to me that DTM introduced an
innovation in 4Q 1995 and its 2 years old. At SME RP&M'97 people
where attempting diminish its innovations because of their own
failures, blaming DTM and not themselves. If your reading this
counterpoint your a member of a forward thinking group of individuals
who should take pride in that. Close mindedness or not continuing to
take risk outside the box will not set you apart from the followers.
Wounded, scared but not dead... There's another hill but I still see
the horizon.
A Rapidtool user.
______________________________ Reply Separator _________________________________
Subject: RE: dtm rapid tooling
Author: Phil Malone <phil.malone@fp.co.nz> at INTERNET
Date: 10/21/97 10:28 AM
Hi Barney Sing
Thanks for the costing information , it is refreshing to get a users =
opinion of a process rather than a sales driven one .
What cost per Kilo does the DTM metal powder material work out to be ( =
$100US/Kg?) if so then that appears to be a competitive=20
disadvantage for this process .
Did some of your costs come from the amount of finishing / polishing =
work required on the inserts? and how did the accuracy stack up for a =
typical injection mould component .
Our requirements are for producing prototype injection moulds quickly =
and cheaply for typical runs of 200 parts for life testing prior to =
final design and production tooling release .
Cheers
Phil Malone
=20
----------
From: Barney Sing
Sent: Friday, 17 October 1997 11:32
To: Phil Malone
Subject: dtm rapid tooling
an ambitious task... rapid tooling!
Our company used and invested in DTM Rapid Tooling.
We found the process to be more expensive than conventional AL tooling.
$14K US dollars to fill a Sinterstation 2000 only 65% full.
A huge amount of AL can be purchased for this amount.
Relatively, our "cost" of a DTM rapid tool was 2-3 times that of
conventional tooling methods... Most part geometries of comparable
complexity only achieved a 3-5 day increase in time. Yet cost us -not
the customer- 2-3 times more. =20
We are no longer using DTM's Rapid Tooling.
--=20
_______________________________________________________
Barney Sing Global Tool and Engineering
Ph: 972.241.4300 Ext. 107 Fx: 972.241.3195
Em: barney@globaltool.com http://www:globaltool.com
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