Machine-DRO

Worried after reading the thread about accuracy of dro's made a check on the B & W system fitted to a Warco A1S mill with 3mm pitch leadscrews.

30 handwheel turns at 3mm = 90mm travel: the dro read 89.95mm.

Then read the dro for each 1 turn of the handwheel = 3mm as follows:

0, 3.00, 6.01, 9.00, 11.98, 14.98, 14.98, 17.99 21.00, 23.99, 27.01, 30.01 For each reading the handwheel was brought to 0 from the same direction.

Set up a 10mm travel dial indicator, used the dro indication for the .00. Rounded off to the nearest 0.01 line on the indicator. Approached each reading from the same direction of travel. Reading up on the dial indicator: dro dial

0 0 1.00 1.00 2.00 1.99 3.00 3.00 4.00 3.99 5.00 4.99 6.00 6.01 7.00 7.01 8.00 8.00 9.00 9.02 10.00 10.00

Reasing down on the dia indicator: dro dial

10.00 10.00 9.00 8.99 8.00 7.99 7.00 6.98 6.00 5.97 5.00 4.97 4.00 3.97 3.00 2.98 2.00 1.98 1.00 0.97

Hope this helps someone.

Doug