RE: machining of STL files

Date: Fri Apr 11 2003 - 14:55:28 EEST

However, if your geometry has a vertex with a sharp angle on one half
(side A), you may have a radius on the (B half) from whatever size cutting
tool being used--resulting in some amount of potential flash.

John Hannigan
Prototyping Development Engineer
Concepting and Fab. Technologies
Production Systems Engineering & Technology
Eastman Kodak Company

Bob Olsen <>
Sent by:
04/09/2003 04:01 PM

        To: "'Rohit Kumar'" <>,
        Subject: RE: machining of STL files

I'd say the mold would seal fine, because you have to mill the A and B
shutoffs to fit no matter what the part geometry. Your part may just look
funky. Faceting shouls only affect the part, not the mold shutoffs.

> -----Original Message-----
> From: Rohit Kumar []
> Sent: Wednesday, April 09, 2003 1:31 PM
> To:
> Subject: machining of STL files
> Hi.
> I had a question on machining of STL files.
> Since STL files are faceted, if mold is machined, what's the
> guarantee that the core and cavity would seal properly
> (assuming the parting line is not perfectly straight and has
> sort of a contour to it)?
> My understanding is that if the resolution of the triangles
> is within that of the milling process, then there is no
> problem. However, if it's not, what happens then? For molds
> made via SLA, the mold material is soft. So applying
> pressure, would sort of deform the material such that at the
> parting plane, the core and cavity make a seal. But say if
> the mold is made out of tool steel, what happens then? BTW,
> is mold ever made out of tool steel via STL files?
> Any inputs will be appreciated.
> Best regards,
> Rohit.

This archive was generated by hypermail 2.1.7 : Sat Jan 17 2004 - 15:17:20 EET