Mach3 not communicating with OMNI 1212 CNC Router

I work at a mobility company where we make a bunch of different products and accessories for wheelchairs and power chairs. Our products like cup holders and other accessories attachment mechanisms are made from HDPE sheets, and we have recently decided to bring the CNC routing in-house. We bought a brand new OMNI 1212 CNC router/sign maker for the task, and it seems like a pretty swell machine (for the price, anyways). The machine itself came with a copy of Ucancam, of which I am beginning to understand.

However, my problem stems from the communication between the program and Mach3(we bought a new copy of Mach3). After a couple test paths, it seems as though the drawings are being enlarged at some point between generating the .nc file and loading the GCode in Mach3. I do not know what to do to solve this, or even where to begin.

I used Aspire and Mach3 in school, so I am somewhat acquainted with the process. I also built and installed a Taig MicroMill for the school, but it came with an edited copy of Mach3 that I assume was already calibrated to the mill, so this is the first time that I am installing a fresh program.

As far as I know, we have not yet done any calibration with Mach3 or the mill.

Any help is appreciated
Sincerely,
Matt

if its working OK other than the parts are too big with mach 3's default settings

how big is the error in size ?

you will need to set up mach 3 as in the mach 3 manual


in mach 3

the units may be set up incorrectly what units are you working in ?

eg mach set in inches instead of mm would make parts 25.4 times too big
if Ucancam is set to mm


then you need to check the steps per unit

the pitch of your lead screws may not be the default pitch

John