Re: What makes a machine CNC ready?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "lcdpublishing"
<lcdpublishing@...> wrote:

>
> That's a pretty bold statement.....

>
> Why would that ball screw fail in 5 years? I have never seen any
> references published that state the life span of a ball screw is 5
> years, 10 years, or 20 minutes.

Ball screws have a rated service life. I expressed it as cup half
empty, instead of cup half full. ;-)

Some Thompson ball screws have a 2.1 million inch rated service life

I estimated this as 3 hr/wk at 50 ipm = 9000 inches per week

5 years at 50 wks per year and 9000 inches per week = 2.25 million
inches.

Several other US manufacturers rate their ball screw service life at
1,000,000 inches. If you read the literature published by the
manufacturers, you can see the detail of how they predict service
life.

Fred Smith - IMService
http://www.cadcamcadcam.com/hobby