scale seems off - new user

I'm a new user to openbuilds - I have used easel for more than a year now and the machine i purchased second hand with an arduino controller. I dont understand a lot about this thing, but i have used it to make signs and things in easel with no problem with scale. I'm trying to do a 3d carve, and used aspire to design something that is 10 inches square, but when i tell openbuilds controller to run program or check size, it acts like the project is 10 mm instead of inches, however when i check if 100 mm really is 100 mm it is within .05 each time. Can someone direct me as to how to fix this please?

openbuilds 1010 machine
custom arduino controller (someone else built it, but its worked fine up until now)

remember, I'm a noob. thank you.

 

again, total noobie. i took the saved g code and opened it right up in the controller. no post processing. can you elaborate?

 

i downloaded one and installed it, but nothing changed. the link you provided is confusing. does it happen automatically after install?

 

so ive got it closer.... the cnc thinks my 10" project is around 8" now, so thats better but not right. Peter, I've read that but i cant seem to understand what i need to do. i have vectric 10.5 any help is gladly appreciated.

 

I am using the openbuilds post processor. using the calibration wizard, it is set to move 100 mm when i say to move 100 mm in each direction. it does exactly as i tell it to, just when the project is loaded and i click check size it moves 8" wide and 7.75 inches tall on a 10" project