RE: milling of clay

From: Mitchell, Doug (D.B.) (
Date: Wed Mar 12 2003 - 17:13:23 EET


We mill clay on a regular basis, and after talking to the operators
and programmers, I found out some things for you to change.

1. Clay is the same that we use, but do not refrigerate it. It will
expand when it returns to room temperature and change all your parameters.

2. No problem on the cutting tool.

3. Feed rate is about right.

4. 8200 rpm - with a 12 mm tool, you can slow the speed down to 2500-3000
rpm. This will create larger chips which are more likely to just fall off.

5. We find that a generous tool path distance (step over) in clay is 0.6 mm.

6. No problem in cutting in both directions.

Finally, as a general rule, milling in clay requires a modeler to finish
the surface by hand.


Doug Mitchell
Ford Motor Company
-----Original Message-----
From: Bram de Smit [mailto:A.desmit@IO.TUdelft.NL]
Sent: Wednesday, March 12, 2003 8:40 AM
Subject: milling of clay
Hi list,
I am wondering whether any of you have experience with CNC milling of styling clay.
I did a small experiment but i was not to enthusiastic. The main problem is that the particles that
are cut of stick back on the surface after the tool has passed.
I used:
- a styling clay (Y2-klay from Chavant) suitable for milling, that I put in a refrigerator before
- a conventional ball nose milling tool with two cutting edges and a diameter of 12 mm.
- a feed rate of 8 mm./sec
- 8200 rpm of the tool
- a tool path distance of 1.33 mm.
- a meandering milling startegy, that means that tool is cutting in both feed directions.
These settings resulted in a not optimal surfaces with lots of clay particals sticked to it.
Can any of you help with some rules of thumb for the parameters that i have to use?
Bram de Smit,
Delft University of Technology / Faculty of Design, Engineering and Production (DEP) / room nr. 10-3A-31 / Landbergstraat 15, 2628 CE, Delft, The Netherlands / Phone  +31 15 2783788 / Fax  +31 15 2787316 / E-mail  A.deSmit@IO.TUDelft.NL /

This archive was generated by hypermail 2.1.7 : Sat Jan 17 2004 - 15:17:14 EET