Machsupport Forum

Mach Discussion => Mach3 under Vista => Topic started by: eoinie on May 25, 2018, 10:43:33 AM

Title: Change Inches to MMs
Post by: eoinie on May 25, 2018, 10:43:33 AM
hi all
I'm having problems setting up my machine in millimetres in mach3. I changed the units in Config but when I save and open the DROs are reading in inches. So if I create a new offset for x0 y0 the machine goes to that offset. But if I load a code with a G21 my offset is altered. Previously my DROs were in mm on startup. How can I make Mach3 default to mm on startup?
Title: Re: Change Inches to MMs
Post by: joeaverage on May 25, 2018, 11:18:14 AM
Hi,
Config/Select Native Units sets the units which you tune your motors and set soft limits etc. Set them once then leave it alone.

Config/General Config.... near the centre is a text box 'Initialisation String' put a G21 in there with whatever else is already there. This is a string of instructions that Mach runs
when it powers up. G21 should cause all the DROs to display in mm.

Craig
Title: Re: Change Inches to MMs
Post by: eoinie on May 25, 2018, 11:39:06 AM
Thanks Craig. Did all that, saved settings an re-started Mach3. G21 shows up in the Active Modes window but DROs still in inches
Title: Re: Change Inches to MMs
Post by: joeaverage on May 25, 2018, 02:45:05 PM
Hi,
the DROs just display numeric text, could it be that the machine is in fact in mm but the steps per unit are such that they give you the impression that the numbers reflect inches not mm?
Look on the Settings tab, lower RH corner. What is indicated as units?

Craig
Title: Re: Change Inches to MMs
Post by: eoinie on May 25, 2018, 04:55:43 PM
Hi
I'm using the Legacy interface so it doesn't have the setting tab. However, I did measure the distance travelled by the tool and it is moving in inches as per DRO

Eoin

Title: Re: Change Inches to MMs
Post by: joeaverage on May 25, 2018, 06:02:02 PM
Hi,
that rather suggests your steps per unit value is in inches also.

Issue an MDI
G0 X0
G0 X1
how far does the x axis move? If it moves one inch then effectively your steps per unit is 25,4 times to big.

Craig
Title: Re: Change Inches to MMs
Post by: eoinie on May 26, 2018, 05:16:17 AM
Yes Craig. The tool moves an inch. The DROs are still in inches but I have a G21 in the initialisation string which is showing up in the active modes window.
Title: Re: Change Inches to MMs
Post by: eoinie on May 26, 2018, 05:28:59 AM
For some reason the Motor Tuning window now won't open. This is a re-installation of Mach so it should be good.
Title: Re: Change Inches to MMs
Post by: joeaverage on May 26, 2018, 05:32:56 AM
Hi,
I think your steps per unit calibration is out.

You commanded a move of 1 unit with the MDI. With G21 active Mach interprets that as 1 mm. It moves A CERTIN NUMBER OF STEPS per your step per unit figure.
It actually moved 1 inch, ERGO the Steps Per Unit Value you have programmed is to high by a factor of 25.4

Go to the X axis motor tuning page and reduce the Step per unit value you have there by a factor of 25.4. Now try the experiment again.

Craig
Title: Re: Change Inches to MMs
Post by: eoinie on May 26, 2018, 05:52:38 AM
Can't open the Motor tuning window
Title: Re: Change Inches to MMs
Post by: joeaverage on May 26, 2018, 06:13:38 AM
Hi,
that's tricky....I migrated to Mach4 about 18 months-2 years ago and Mach4 seldom suffers those sorts of faults.

I think you are going to have to reload Mach. Do you have a licence for Mach3?

Craig
Title: Re: Change Inches to MMs
Post by: eoinie on May 26, 2018, 06:56:19 AM
OK so I got the Motors Tuning window to open after several restarts. I have the native units set as MMs. I have G21 in initialisation string.
When I launch Mach3 I see G21 in the Active Mode window but when I press re-set it changes to G20. The motors are displaying mm per minute on all axes. When I test the actual movment on e.g. Y axis an actual 1 inch tool movement shows as approx  4/100ths of an inch on the DRO
BTW I do have a Mach3 license.
Title: Re: Change Inches to MMs
Post by: eoinie on May 26, 2018, 07:24:50 AM
Current situation is as follows:
I have a code with a G21 loaded. Native units show mm. Active Mode shows the G21. Motor tuning showing MMs per minute.However DROs are still inches and actual spindle movement is also in inches. I'm at sea here and in dire need of this machine.
Title: Re: Change Inches to MMs
Post by: Tweakie.CNC on May 26, 2018, 07:35:20 AM
Hi Eoinie ,

Try the Axis Calibration feature (Settings screen).

Click 'Set Steps per Unit' and follow the on-screen instructions. (as you are working in metric units - if you command a movement of 30 then the DRO should increment 30.0000 and the axis movement should be 30 mm).

Tweakie.
Title: Re: Change Inches to MMs
Post by: eoinie on May 26, 2018, 08:00:20 AM
Thanks Tweakie. My problem here is that I have a Legacy custom screen which doesn't feature that settings screen. I have had issues with that before. I think I have on older version almost working now. However my lingering problem is that I still don't get a MM DRO. It works fine when I have  code loaded which contains the G21 but only then. My original setup was using metric even with no code loaded. I know its not critical and I'm a whole lot better off than I was but I would love to have it a completely metric interface for setting offsets, positioning etc.
Title: Re: Change Inches to MMs
Post by: Tweakie.CNC on May 26, 2018, 10:57:26 AM
Ahh well, it was just a thought.

Tweakie.
Title: Re: Change Inches to MMs
Post by: BungalowBill on October 29, 2018, 06:50:41 AM
Hi,

I have a legacy Arty, my machine was in inches. I contacted customer support through email and Mosiah was very helpful updated my software and converted it to metric via Team Viewer. I am in Australia so Utah hours are my sleeping hours and I did not have to be at the pc. The feed DRO? could not be changed and remained in inches per foot, I have not been at the machine long enough to work out if the numbers actually relate to ft or mm. I also asked him to change the tool change position to the centre of the bed but the same centre position of the fixed touch off pad ie y = +300    x =  50.? centre of touch off plate, if you know what I mean. I seems easier to change the bits over there and it still touches off ok when setting up the auto tool change.

Cheers