Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: rockaukum on April 01, 2017, 02:03:19 PM

Title: please confirm or deny mm to inches cut question
Post by: rockaukum on April 01, 2017, 02:03:19 PM

I have a drawing in mm and would like to cut it (router) on the CNC with Mach3.  Mach3 is set up in inches.  If I want to cut this out without changing Mach3 over to mm, can I go to the setting tab and make the change in the box at the lower right to mm?  I do not want to reconfigure the software along with motor tuning in mm as this is pretty much a one time cut.
Any help with this would be great!
Thanks much,
rockaukum

Title: Re: please confirm or deny mm to inches cut question
Post by: joeaverage on April 01, 2017, 03:18:41 PM

Hi,
do not change Machs Native units. The native units are used on the tuning page, thus if you've set inches as native units then your
'steps per unit' setting on the tuning page is 'steps per inch'. This setting is made when Mach is setup for the first time at NOT touched
thereafter.

To cut a gcode program which is written in mm use G21 at the very start of the program. To turn the machine back to inch units code G20.

Craig

Title: Re: please confirm or deny mm to inches cut question
Post by: rockaukum on April 01, 2017, 03:53:39 PM

Thanks joeaverage,
Yeah, I figured that I did not want to change the "native" units on the machine.  So If I load the gcode and the line reads "G20" I want to change it to "G21".  After the cut is done, I will need to change the "G21" back to "G20".  With this done, The cuts will run as drawn (metric).  correct?
I'm guessing that the G20 and or G21 is originated via Mach3 and not through sheetcam where the code was created?
Thanks again!
rocaukum