Re: [CAD_CAM_EDM_DRO] ...but how much precision????

I have also measured and mapped my gantry machine.

I used 12", 6", and 3" precision micrometer test bars in various
combinations
to measure over the entire 5'x5'x1.5' work envelope. I also have a huge
class
N precision square. After correction I was within 0.001 positioning
everywhere
at precisely 25 degrees c. Cutting error is of course poorer.

And if the shop temperature rises just from 25c to 30c the whole thing grows
about
5 thousandths. Expansion from ballscrew heating in hard use results in even
more error.

I think position error goes as to about the inverse square of cost. It is a
big
deal and big $$$ to do this.

Les
Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.alltel.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.alltel.net/~leswatts/shop.html
Surplus cnc for sale:
http://www.alltel.net/~leswatts/forsale.html

----- Original Message -----
From: "Bill Kichman" <billkichman@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Thursday, May 08, 2003 10:39 PM
Subject: [CAD_CAM_EDM_DRO] ...but how much precision????


> Has anybody truly measured the degree or precision you are getting from
your installation? Is 1 thousandth attainable from home cnc?
>
> Bill K
>