Re: Large machine construction and temperature control

Some of the high precision machines don't just spec
temperature control, they actively provide it. There
are fluid channels in the ways and screws (yes hollow
ball screws) and a system to pump constant temperature
fluid through them.

Cheers,
Steve Stallings

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Ken Jenkins <kjenkins@b...>
wrote:

> The following reference in a previous post got me thinking
>
> >>> http://www.scaled.com/services/cms_mill.html
>
> A friend of mine works with the aerospace industry doing QC

fixtures for 3D

> tubing. He is constantly telling me about the tolerance these giant

milling

> machines work to. The thing I don't understand is, for a machine

that large

> one would thing that just expansion due to temperature fluctuation

would

> cause the machine to go back and forth several thousands over a

whole tool

> path over time.
>
> Can anyone address how the manufacturers of these kind of machines

manage

> this issue (other than spec'ing that the machine must run in a

controlled

> environment?
>
> Do those of you who have built larger (NOT as large as the above)

CNC

> routers, plasma tables find any problems as a result of heat

expansion of

> machine parts?
>
> Just curious,
>
> Ken Jenkins