I’ve had my machine about two months and I’ve hit a problem that has me at a loss. While carving a sign several letters are lower than the rest. Everything is typed as a whole and looks good on the grid and on the preview page. Does anyone have any idea why this is happening? Thanks for the help!
While I think I understand your problem a picture is worth a 1000 words 
Sounds like your Y-axis is slipping/binding causing the steppers to fall behind on their intended position.
These machines are open-loop => the controller have no positional feedback from the steppers so if they for any reason fail to do their travels the controller is unaware.
I would look to see if part of your design extends beyond the reach of the machine.
Good suggestion, if the machine for any reason reach maximum travel it will stall out at that point and loose steps.
The design spans 30” by 16” tall but the part that is giving me problems is in the middle. I cut one the other day like it with no problems.
While your design problems manifest themselves in the middle the error might have occured earlier.
Say Y axis is told to move 10" away from you but for some reason it bump into something 9". So when the Y is asked to come back 10" it overshoot by 1".
But your machine is loosing steps, question is why.
Make sure your $1=255 and that the Xcontroller board dip switch #4 is set to OFF.
This disables any torque reduction functions for your machine.
Are you using MDF for your waste board, and is one side lower than the other? We had a similar issue with our mdf waste board that we’d been using for about 3 months. We just resurfaced it over the weekend to get back to a level board and it’s already made a big improvement on our carves.