Dimensions Slightly Off

X axis attachment images attached.

Looks like maybe a latency problem.

LinuxCNC 2.5 is really old (2012) and may not have had the reset option
If the PC is of similar vintage, it may have issues. Overheating
or hard drive failure can cause latency problems to develop
in a system that worked previously

Since this is such an old LinuxCNC installation, did the machine work ok
and just fail recently?

 

Same behavior when oriented on the other axis:

 

Note the difference between the first and second layers, show by the red arrows. 

Background on PC/LinuxCNC setup: We bought an ASRock q1900b-itx to install. When I retrofit the router to use LinuxCNC via this board, it kept giving latency errors. Next to our router, we have a LinuxCNC mill that uses a different computer (not sure the model on that, but same LinuxCNC version). It's never had latency problems and the mill has always worked, so I switched over to that computer and set up the router and keep getting these same skipping issues (again, issues that are not present on the mill that uses the same computer). The router itself has never had this kind of issue on the old RichAuto controller, so it just started having this problem when I set it up with LinuxCNC (started about a week ago). We use this router all the time, it's not like it was sitting in the shop unused for a long time before setting up.

What voltage is the power supply?
Try speed at 200 and 100.

The power supply powering the drivers is 24 V. Note that when I set it up for LinuxCNC, I added a 5V power supply (for the breakout board) that just pulled off/shares the A/C leads going into the 24V supply.

Will try those speeds.

You set up a new system with LinuxCNC 2.5?

I guess a Breakout board/parallel port/cabling issue is possible as well