Re: Newbie - Z-axis slipping

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Janice" <bigforkshop@y...>
wrote:

> I'm brand new, self taught on my CNC router/engraver. I am
> currently using a single drill point function where I am drilling

30-

> 90 holes per part, at a precise depth of 0.043. I am losing depth
> starting at about hole 25, and losing up to .030 worth of depth

over

> the course of the remaining holes. Am I expecting an unreasonable
> level of precision, or are there some explanations for why a Z-axis
> would lose depth? Thanks in advance!

Chances are pretty good that your depth loss is due to thermal
effects (e.g., thermal expansion). Even stiff, heavy-duty industrial
CNC machines need to have their offsets readjusted after they warm up
or after they've been running for a while.

Jesse