When you import a model that was saved in inches it might not be visible in Gizmetor because it will be so tiny. If the model is small enough Gizmetor will automatically show a message stating that the model might be in inches. With the message box you can then automatically convert the model to mm so that everything works perfectly in Gizmetor.
Some models might move all the built plate when this conversion is done. You will need to zoom out and move the model back onto the build plate.
it is best to now save the model so that you don't need to go through this process again in the future.
Left click on the model, right click and click on Save Selected. The model size and position will be saved.
You can also convert an existing model from inches to mm or back to inches.
Left click on the model, right click and click on Precision Scale.
On the Precision Scale widow you can then change the model from mm to inches and back again.