>:(Thing were working fine, but I had to change my P.port Breakout board from Probotix, now I am losing position in a negative direction, meaning x and y distances are getting smaller.  Do I have to re-tune the motors and change the math on the leadscrews?

Inivator

No, changing the breakout should make no difference at all, make sure all conections are good, grounds etc are connected.
 Why did you have to change the breakout?
 Is it the same type of breakout?
If all was working with the last breakout and you have not changed any settings since then either the wiring is not 100% or the breakout is not 100%

Hood

The breakout is the same.  I had to change it because the limit switch chip was bad.  Probotix change the board, and the limits are working fine.  Now the repetivative move are not the same.  This is the problem, I stated yesterday, in the abnormal ref-all post. 

Inivator

 If it was working fine as far as movements are concerned and you have changed nothing in Mach then I am afraid it looks like your new board is not good.
 Try setting the pulse width to 5 in Motor tuning or maybe even trying Sherline mode but to be honest if it was fine before the changeover then it doesnt look like that would help.
 Can you put the old board back in easily to see if things are back to normal?
Hood

Will try that. Thanks.

Inivator