Messages

1

General Mach Discussion / Re: Zeroing machine coordinates

« on: August 24, 2010, 04:34:45 AM »

After some research of the vb-scripting, I put together something that actually worked very well. So now I have my machine coordinates set as they are, permanently. Basically, I added an unused M-code in the post-processor that gets run at the very start of the program. This runs a script in Mach3 that sets a gauge-level variable from the machine Z. Then, I mapped a button to another script that sets the current tool-offset to the difference in current machine Z and the previously stored gauge-level.

So, now all I do is move first tool to stock zero and zero fixture coordinates. Then I move to some table-related constant, either the surface or something else and start the program. Upon each tool change, fit the new tool, move it to the gauge-surface and press my custom button and continue the program.

So, this is effectively what BR549 suggested, but without having to write anything anywhere.

Thanks for your help guys!

2

General Mach Discussion / Re: Zeroing machine coordinates

« on: August 23, 2010, 02:37:41 PM »

That sounds like a good way to do it. Now I just need to make a script so I don't have to manually enter any numbers. Should be possible. Anyway, thanks for your help.

3

General Mach Discussion / Re: Zeroing machine coordinates

« on: August 23, 2010, 07:15:00 AM »

But then the code have to be referenced to this gauge level also. I really like to use Z=0 in the CAM as the top of the work-piece. Then, no matter what fixture I use, the code will always be the same.

I think I should look into the offset functions a little more. Perhaps it can be automated so I touch off the first tool on the table, set the offset to zero. Then touch off on the work-piece, zeroing the G54. Then, after tool-change I can just touch off on the table and set the offset to the difference in machine Z. This would also work if I used some kind of pressure actuated switch for semi-automatic operation.

4

General Mach Discussion / Re: Zeroing machine coordinates

« on: August 23, 2010, 05:23:55 AM »

I know very well this is not how it's supposed to be done. The problem that I see is that I can not always touch off the second tool on the work piece as the surface might all have been machined off. But I guess the best would be to manually, or preferably by a script, be able to touch off each tool on the table or another fixed surface then have the G54 coordinate system update so that its Z=0 would be where the work piece surface would be.

5

General Mach Discussion / Re: Zeroing machine coordinates

« on: August 22, 2010, 08:35:00 PM »

If I zero the G54-coordinates I loose the reference for Z. I need the tool-tip of the G54 Z to be exactly the same after tool-change.

6

General Mach Discussion / Re: Zeroing machine coordinates

« on: August 22, 2010, 07:44:16 PM »

Well, semi-true. The limit for max-Z will not be accurate, but the low-Z will make sure I don't slam the tool into the table. X and Y still works fine.

7

General Mach Discussion / Re: Zeroing machine coordinates

« on: August 22, 2010, 07:39:16 PM »

This way I don't have to enter any coordinates at all. I just have to jog the tool to table and press a button. Unless I have a Z-level which is not machine with a previous tool, then I can off course just zero the user coordinate touching off on the work-piece.

8

General Mach Discussion / Re: Zeroing machine coordinates

« on: August 22, 2010, 07:26:10 PM »

BR549: I am working in user coordinates, but I want to reference tool-tip touching table as machine Z=0

Let me explain better.
The G54 is no problem to zero or set to any value at any time. But, as I don't have home switches and still want the machine-coordinates to be accurate, I have to zero the machine manually. I do this by moving it to zero with the drivers turned off and then pressing ref all home (with auto-zero on x and y) to get the machine coordinates to zero. Now when I turn the driver on real position of the machine is the same as the machine coordinates.

Hood:
Yes, that is almost how I do it now. I would also touch off the second tool on the work-piece, but it's not always possible as the whole surface might be machined by a previous tool. Therefore, I use machine coordinate Z=0 when the tool-tip touches table.


Actually I think I found a solution by my self. SetMachZero(2) script-command seems be the equivalent off ZeroZ (for machine coordinate). Maybe mapping it to the Auto Tool Zero would make good use of that button.

9

General Mach Discussion / Zeroing machine coordinates

« on: August 22, 2010, 06:14:05 PM »

Hi,
I am quite new to all of this CNC-stuff, but I have successfully got my milling machine up and running and have run my very first program.

But, I have trouble with changing tools within the same program. I change tools manually, and I don't have any home-switches or means of detecting tool length.
So, the way I run a program now is:
Mount tool #1
Jog down until tool-tip touches table
Zero Z machine-coordinate
Jog to corner of work piece with tool-tip touching the top, which is my (0,0,0) in the CAM-program (and (0,0,0) in G54 fixture)
Run until next tool change
Mount tool #2
Jog down until tool-tip touches table
Zero Z machine-coordinate
Run rest of program

I plan to semi-automate the Z-zeroing using a switch later.

Anyway, all this works just fine. The problem is that I can not just press the ZeroZ-button to zero that coordinate (nothing happens). I must use the "REF ALL HOME", with auto-zero enabled only for Z. As I have no home-switches, the only effect is that Z is zeroed. This also means that to actually home the machine, I'll have to turn of the drivers, move to home, enable auto-zero for all axis, "REF ALL HOME" and turn on the drivers. Then I have to disable auto-zero for X and Y before doing the program run procedure above.
Sure, it's not very hard to do, but it would be much better if I could just click the ZeroZ-button and have it zero that machine coordinate (and not affecting the work piece coordinate system G54).

Is there a better way, or can I enable the ZeroZ-button, or could I perhaps do this with a script of some sort?

Regards
Alex