RE: STL-based HSM

From: Finelt Paul (
Date: Tue Jul 09 2002 - 15:29:46 EEST

While I haven't tested the HSM tool path capabilities of Delcam's PowerMill,
I can tell you it is extremely fast in generating tool paths. I have never
seen complex, pencil trace and re-machining tool paths calculated so fast.
Most tool path generating programs approximate points on surfaces unless
they are generating NURB tool path commands. If your STL file is tessellated
to an adequate accuracy the tool paths should not be a problem either. I
have tested this on small parts ( < 50.4mm, 2" max. dimension) and never
found tool path error to be measurable in a shop environment (i.e. greater
than total machining tolerances or +/-.001",.025mm).
I have always believed that the shop should not change a part design. Adding
machining geometry (boundary curves, etc.) does not effect that.
Best Regards,
Paul Finelt
Director, Product Design and Product Engineering
Swarovski North America
1 Kenney Drive
Cranston, RI 02920-4400
voice - 401.463.2757
FAX - 401.463.4757

-----Original Message-----
From: Chang-Shik.Min []
Sent: Monday, July 08, 2002 10:01 PM
Subject: STL-based HSM

 Dear RT professionals: are you ?
I am very much interested in STL-based HSM(High Speed Machining) as a
research engineer in Rapid Tooling,thinking it will be one of key
technologies to innovate the existing HSM technology.Yes,I know some CAD/CAM
softwares like Delcam/PowerMill or Delft/DeskProto have direct interface
with STL data.
I,however,have following questions about that;

 1.Tool path accuracy problem resulting from triangulation.
 2.Speed for tool path generation and machining.
 3.Problems caused by the fact that STL data can not be changed once
   in a CAD system.

Is there any one else out there who can share your experience or knowledge
on the above with me ?
Any opinion you could give me would be greatly appreciated.

Rapidly yours,

======== Nothing ventured,Nothing gained! =======

Chang-Shik,Min (Chief Research Engineer)
LG-Production engineering Research Center
LG Electronics Inc.,Republic of Korea
(Phone) +82-31-660-7090,+82-31-202-8009(Home)
(Mobile) +82-19-370-7424
(Fax) +82-31-660-7384


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