Hi all. I am working on a JGRO style build. To speed things up and to have immediate access to a CNC machine, I went ahead and purchased a Zenbot 1216 (edit: Didn't buy it on eBay.) Pretty nice machine for a newbie. However, I am running in a problem, I believe with my RotoZip. I can't seem to get parts to size up correctly as they have been drawn.

Here is what gets me. So I drew a 1"x1.5" rectangle and generated some G-Code with CamBam. When I run the program, I end up with a 0.9725"x1.468"x0.75" rectangle (cut from a sheet of 3/4" HDPE.)

I've been reading up on router runout and it seems like this could be related. I'm baffled, any ideas?

FYI, I am using EMC2 for step generation. I am pretty sure I have everything set up correctly. I am using a config file sent to me by Zenbotcnc.com.