Quote Originally Posted by Robin Hewitt View Post
Uh? Irving? I think you'll find .025mm is 25um.

Sounds like you may have overdone the New Year celebrations :heehee:
B***er you are right...

Over a 300mm length C7 gives a overall worst case positional accuracy of .07% and C5 gives 0.013%

If absolute step position is paramount then C7 gives, worst case on 5mm pitch, an absolute step to step position error of 2% (of resolution) against C5 of 0.8%

Doesnt change the conclusion tho, C5 is an unnecessary expense