I've just finished installing a 6" Igaging from American eagle on my mill Y axis. I made sure there was no binding between the scale beam and the reader the whole 5.5" travel. I've compared the accuracy with my mill dial and I get a +.010" over 5" travel.
I double checked with a 1" dial indicator and got a .003" error over an 1"
Here is my numbers
Milling dial 1"dial indicator Igaging
.000" .000" .000"
.100 .100 .099
.200 .200 .199
.500 .501 .498
.800 .801 .798
1.000 .999 .997
2.000 1.994
3.000 2.992
5.000 4.990
I've bought all my linear scale to do my mill and one for the lathe apron (6", 12",24" and 35")
But I'm debating installing the other scale if the resolution is going to be .011" per 5" travel. ( spec are - + .002" per 6")
I need to investigate more.
I've pull and push on the mill table and there was no change in the DRO and my dial indicator. (somewhat checking gib and worn screw nut ?? )
Has mention in the previous post, I will mount a dial indicator on the provided scale mounts to see if I get any deflection while moving along the total travel on the Y axis.
Any advise is welcome!
Thanks!
Phil
Update
Well after looking at the bracket deflection (none was found)I realize my initial mounting was not that great after all. The digital scale beam bracket installation was off of parallel to the y axis by .020" DuH! So after some shimming I managed to improve the accuracy to .003" over the 5" travel. I'll be tweaking some more when I get some more shop time available

Cheers!
Phil