X-Carve has stopped cutting to the depth I have it set to

Title says it all. The bottom of the lettering on my last job was all over the place. When that one was finished I started a totally different project. The depth per pass is set to .06in and instead it’s taking off maybe a 64th per pass. I’ve probably carved around 100 things and this is the first time its done anything like this.

Check the set screws on the Z screw pulley.

They’re tight and its still doing it.

How accurately are you measuring the material thickness? If it’s thicker than you expect, the depth of cut will be more than you intended.