Sabre408 Y-Axis issue
Hey everyone.
I have an old Sabre 408 using Composer 1.56.
I am cutting 1/8" wide dado's, 0.050" deep into styrene plastic sheets in which to fit 1/8" thick pieces of styrene. (They have to be a little wider than 1/8" or an easy fit as plastic thickness can vary slightly)- so, not machine-perfect.
Since the bit is 1/8", we do "follow the line" on a very thin rectangle.
There eventually started to be a bit of inconsistency across the table in the dado widths along the Y-axis; they were either fine, or too tight, (as well as noted issues with circle roundness).
The dado lines have been made the same way in Composer for over 25 years and we've largely had no issues with them. There were a lot of potential factors, and I'm profoundly limited for funds, so I started chasing down a solution on my own.
I have done the following:
I adjusted the backlash spring.
No difference.
I replaced the lead screw!
No difference.
I calibrated it's orientation to home to 1/8" (within their 3/16" tolerance).
No difference.
I squared the gantry.
No difference.
I brought in a second computer, fresh-installed Windows XP, fresh-installed Composer/ARTPath. All smooth installs.
No difference.
I adjusted the belt tension on the Y-axis servo by letting the spring set the tension.
No difference.
It still cuts dado's that are too tight and I just don't get it anymore.
Does anyone have any experience with this kind of trouble and found a solution?
Many thanks in advance.