Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Giulio Buccini on July 11, 2021, 06:10:44 AM

Title: How to enter&set a new arbitrary tool position without zeroing it?
Post by: Giulio Buccini on July 11, 2021, 06:10:44 AM
Hi all,

I have used only LinuxCNC in the past, so I'm quite new to Mach3.
I'm trying to learn as much as I can about Mach3, but still some things are obscure to me. Be patient.

My case:
as good habit, I always make a test of new g-code by doing a cut "in the air" before using it.

Below there is an example of what I usually do.

1. zero the Z position on the surface of the raw material;
2. raise the tool at the "safe height" of 10 mm above the material (just an example value);
3. set current position as the new Z=0 height;
4. run the g-code to test it by cutting some air.

After all is ok, I would like to restore the "real" Z=0 value, that is:

5. move the tool to current zero;
6. set Z=10 as new Z position;
7. run the g-code and cut the material.

How do I achieve step 6?

In LinuxCNC I simply manually enter the value "10" for the Z axis and press a confirmation button. After that the current WCS (for example G54) is modified accordingly.
Title: Re: How to enter&set a new arbitrary tool position without zeroing it?
Post by: JG on July 11, 2021, 08:42:14 AM
Go to the MDI tab - the second from the left -  just above the [RESET] button is [Input] -- enter G0 z-10 then reset the Z axis to 0.0000
Title: Re: How to enter&set a new arbitrary tool position without zeroing it?
Post by: Giulio Buccini on July 11, 2021, 09:20:29 AM
I know already that way. But it implies moving the tool...  :(
In LinuxCNC you can do that without zeroing the tool.

No other ideas?

P.S.
It seems silly to me that a so widely used software offers zeroing as the only way of changing a WCS (Working Coordinate System). There must be another option hidden somewhere.
Title: Re: How to enter&set a new arbitrary tool position without zeroing it?
Post by: Giulio Buccini on July 11, 2021, 02:56:12 PM
SOLVED.

Just:

1. double-click into one of the DROs (X, Y, or Z);
2. enter the value;
3. hit the Enter key.

Mach3 will automatically update the origin of the current WCS (i.e. G54) accordingly to the value entered.

For example, if the current X is 0 and we set the current value to X=10, then the origin will be automatically translated of -10 units along the X-axis.
Title: Re: How to enter&set a new arbitrary tool position without zeroing it?
Post by: JG on July 11, 2021, 03:13:00 PM
Well, there's a turn up !   I haven't needed to take such action but now you point it out it could be very useful.
On my own system I have a minor mis-match with my [Home] position which used to be X+200, Y+100 but a while ago - after I'd created a Clamping Table - it stared to read X+201.xx (can't remember the exact figure) and I have had to align the X axis to my Clamping Table manually each time I have to do a [Reset] which is a bit of a pain, This 'trick'  -  obviously not a trick but a 'Feature' which I hadn't come across  -  will hopefully bring back some sanity. I'll do some testing tomorrow.
I'm pleased that I thought to offer a solution even though it wasn't useful :)