Re: [rp-ml] STL for bench marking RP

From: <>
Date: Mon Nov 08 2010 - 17:54:49 EET

In a message dated 11/8/2010 5:46:05 A.M. Eastern Standard Time, gsa writes:

Can anyone point to stl file(s) and literature for calibration /
bench mark part which is used to investigate shrinkage / surface
finish / errors in a built prototype etc.
G Saravana Kumar

Dear Dr. G:
In the early days a number of techniques and files were generated
specifically for testing the accuracy of stereolithography parts and these were
used on other technologies, as well. The Windowpane and Christmas tree were
developed to determine shrinkage, flatness, etc. A so-called "User Part"
was developed for positional accuracy. A number of comparative studies were
done, although none all-inclusive, nor were they repeated to reflect
on-going technology changes over the years.
A good summary is provided in Chapters 10 & 11 of Paul Jacobs early (1992)
book which is the very bottom entry on this page:
Other authors may have covered the ground, as well. I may have some of
the test files someplace, but it would take a bit of searching. Let me know.
I'm sure members of the SME group or GARPA can point you in the right
direction, as well. Find them here:
_ (
One individual who has done some fairly recent comparative studies using
more-typical application files/parts is Todd Grimm. Take a look at his
web-site where I'm sure they're described and possibly still available:
_ (

Ed Grenda
Castle Island Co.
_EdGrenda@aol.com_ ( (email)

The Worldwide Guide to Rapid Prototyping
_www.additive3d.com_ (
Received on Mon Nov 08 17:48:15 2010

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