G53 oddity

[tmead]

After previous experience with our older machine failing to move in fixture coordinates directly from home (complaints about soft limits) I added G0 G53 Z-1 and G0 G53 X-1Y-1 to the beginning of the code. This worked a treat.
We now have a second machine, and it's running a newer version of Mach3. Things seem to be different ! On the newer machine the G0 G53 Z-1 command does send the head to Z = -1 in machine coordinates, but on the first run after Mach3 startup it also sends the X and Y axes right across the bed, which is around 500mm travel. They happily then move back to machine coords -1 on the next command. These commands are being issued from a Vb button, with the While/WEnd loop between them. Further runs after the complete script is run do not elicit the same behaviour ! On this machine, I can simply remove these preparatory moves from the script and it seems happy to run in fixture coordinates right from the get-go.

Any ideas ? I was more than a little surprised to see X and Y movement as a result of a Z command !

I cannot upgrade the software on the previous machine as it is being run in a locked down environment, and any software changes will probably need extensive verificaiton testing.

if anybody wants the complete set of xml/set/bmp/macro/fixture.dat/gcode I can send it !

Tim

[Hood]

Yes, please attach the xmls etc.
Hood

[tmead]

Thanks for the prompt response. I'll stick them on this thread when I'm back in the lab tomorrow.

Tim

[tmead]

OK, here's a zip with what I think is everything. no guarantees though !
Should include : xml, set, gcode, macros, bespoke bitmaps and a photo of the machine. The Mach3 setup drives a gantry type 3 axis machine with a cylindrical cutting blade on the spindle that cuts pieces out of a slab of material. Not quite the normal CNC machining setup ! X is across the table, and Y is up and down the long axis.

Bitmaps live in the bitmaps directory, and the screens do use some of the standard bitmaps from the millbitmaps directory, but that's one benefit of Klaus' machscreen - it tells you when bitmaps are missing.

The new machine is running Mach3 version 3.042, and the older one is running 2.42 (can't be changed without a big hassle)

Please let me know if i missed anything

Tim

[tmead]

now that was quick - congratulations to whoever downloaded the file within 3 minutes of posting !

<chuckle>

Tim

[Hood]

Ok got it downloaded and installed and looking Ok, will have a look in a bit after I get the job I am working on finished.

Hood

[tmead]

Many thanks for the prompt attention Hood !

Tim

[Hood]

Which button and screen page are you running?
Hood

[tmead]

The system doesn't quite run like a normal CNC mill or lathe with a single page for a particular function, they flow in sequence to try to minimise the skill level and training requried of the operator.

The system starts up with page 1, and on pressing the image button the axes home and DROs/labels/variables are initialised and then a prompt pops up asking which format to cut. Selecting 'slab' brings up page 2 to assess the position of the clamp jaws with a colour discriminating sensor (funky piece of kit from Omron and not ridiculously expensive). The issue comes when the 'find clamps' button is pressed. I've got a feeing that the file I sent has the G53 command commented out to avoid the movement, so have attached a slightly earlier version (18) of the screen set.

When the clamp assessment is complete, screen 3 is displayed to allow an operator to set up the cutting order for the required quantities of the four sizes of material.

Tim

[Hood]

Yes it did have the G53 commented out and if I recall a Home Z command, well thats if I was looking at the correct button
Hood