Re: [CAD_CAM_EDM_DRO] What is the weak link in machine precision?

You should have no trouble holding .001" if you use ground ballscrews
and quality components, tools, fixturing etc. You will have to take
thermal expansion into account - I just completed a big job (over 700
hours) on my knee mill and was able to hold .02mm (about .0008") on one
dimension all day long. As the machine warmed up through the day, I
would take a couple of .01mm increments off my Z0 offset to compensate.
My part was about 5" x 4" x .75". My Z is via the knee and I have not
seen any significant wear - just a very nice, bright shine on the
chromed ways.

Cheers, Peter

zipdrive2k wrote:

>I am wanting to retro-fit a knee mill for prototyping aluminum and
>some steel tooling dies. Many of the parts are complex surfaces and
>require 3 axis simutanious machining. I need to keep the machine
>accurcy in the 0.001" to 0.003" range. Quill will be locked and knee
>will be moved for z-axis. Extreem speed is not a requirement.
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