inventor/hsm post process issues

hello, I am running a home built machine using USB cnc driver, I have used inventor to create my parts and my cam file.
everything there seems correct all the tool paths and operations as I want. my issue seems to be when I submit to post process, this seems to shrink the size of the parts. taking total cut length from 1700 inches to 65 total inches. I'm not sure what it is that I am doing incorrectly to cause it to shrink.

possible assumed reasons.

wrong machine selected?
miscommunication between inventor and hsm?
scaling option selected in one or another?

please help

Thank you

What post processor are you selecting in Inventor? I too use Inventor for my home built CNC machine using both the UCNC ETH 300 controller and Mach 3 and select the Artsoft post processor Mach 3.

This is pretty close to the inch/millimeter conversion factor. Maybe its in the wrong units?