Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: KiwiCNC on May 04, 2018, 07:42:38 PM

Title: X and Y Alignment
Post by: KiwiCNC on May 04, 2018, 07:42:38 PM

As I am extremely new to this, I have to be very careful, and try to use the right language to describe the problem I am experiencing....otherwise you will be more confused than me  :D

I have my work piece located on the bed, touched off and set the ZERO for all three Axis.

However, when I load my simply GCODE - the table view show the work piece with an approx offset in -8mm in Y and -3mm in X

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 08:02:04 PM

Hi,
have a look on the Toolpath Tab and look at the 'Program Extents' block.

From your description the Gcode file has its leastmost extents of -8mm and -3mm. It means that the Gcode is not starting
at the outer most corner but 8mm and 3mm iside the boundary.

Craig

Title: Re: X and Y Alignment
Post by: KiwiCNC on May 04, 2018, 08:15:43 PM

You might be onto something
How do I change this ...when I enter a value it resets back to the 11 and 4

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 09:32:52 PM

Hi,
you can't change that, those are the extents that the machine will go with the Gcode file you have loaded. You could change the Gcode....or
load the Gcode and then using the jog buttons jog to the material edge THEN zero the axes. You will have to 'Regen Toolpath' several times while trying to locate a suitable
starting location.

Craig

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 09:35:59 PM

Hi,
by the way when you attach pics use a program like Paint to reduce the size.....a 4Meg photo loses its ability to convey info when you have to scan around, sub 200k is enough.

Craig

Title: Re: X and Y Alignment
Post by: KiwiCNC on May 04, 2018, 09:46:49 PM

4MB noted.....

If I jog to the 0,0,0 of the work face then run the code....the machine tries to start the work in space....is it thinks the work is offset I think

Doing my head in  slightly

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 09:57:46 PM

Hi,
essentially the problem is that the 0,0,0 of the blank material is not the 0,0,0 of the Gcode.

Its not particularly convenient but if you put the tool tip inside the boundary of the material blank at the Gcode 0,0,0 then hit start you'd be fine.
Another trick along the same lines....if the program extents are -14mm  and -4mm. Jog to the corner of the material and zero the axes.
Issue an MDI G0 X14 Y4. That should now be co-incident with the Gcode 0,0,0. Zero the axes again and hit start.

Craig

Title: Re: X and Y Alignment
Post by: KiwiCNC on May 04, 2018, 10:17:16 PM

I enter this in the MDI tab and get the result

Unknown word where unwary operation could be

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 10:29:02 PM

Hi,
I suspect that you must be entering a bad character. MDIing is as old and as basic to CNC as the hills.

G0 X14 Y4.....just to confirm that  is 'G' 'zero'

Craig

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 10:31:31 PM

Hi,
whereabouts in NZ are you.....I live in Akaroa, about 80k from Christchurch.

Craig

Title: Re: X and Y Alignment
Post by: KiwiCNC on May 04, 2018, 10:32:36 PM

Auckland

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 10:39:56 PM

Hi,
I am sorry about that! LOL.

A few years back I was sending a boat prop to a company in Albany, and I wasn't really too sure I knew where Albany was so I addressed it:

......
Albany,
Somewhere North of the Bombay Hills.

The guy I sent it to must have a sense of humour because when he sent it back he addressed it:

........
Akaroa,
Somewhere South of the Bombay Hills

Good for a laugh...he made a fine job of the prop too.

Craig

Title: Re: X and Y Alignment
Post by: KiwiCNC on May 04, 2018, 10:45:27 PM

Anyway

I'm none the closer

Feel like a Messenger video call so I can show you the problem

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 10:57:52 PM

Hi,
the MDI works here.

Craig

Title: Re: X and Y Alignment
Post by: KiwiCNC on May 04, 2018, 10:59:34 PM

Yep got that to enter

But still tries to cut in space, Lost in Space so to speak

Ray

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 11:13:25 PM

Hi,
can you post the Gcode file. Should be able to attach it.

Craig

Title: Re: X and Y Alignment
Post by: KiwiCNC on May 04, 2018, 11:15:22 PM

East ya hear out

I was at Akaroa in December...nice little ice cream shopon the way.....

Title: Re: X and Y Alignment
Post by: joeaverage on May 04, 2018, 11:38:47 PM

Hi,
OK I got that. There appears to be two basic toolpaths, the first a facincg routine cut to a depth of -0.5mm. Then another adadptive?
toolpath but its eventual cut depth is only -0.1mm. Your facing cut is already deeper than that????

Anyway may I suggest breaking it into two Gcode jobs. The reason is that you will be able to avoid the M6 toolchange which I bet is giving you grief. Do you
have an Auto Toolchanger?  If not try to avoid M6's.

Code: [Select]

G90 G94 G91.1 G40 G49 G17
G21
G28 G91 Z5
G90
(FACE1)
S3000 M3
G54
M8
G0 X41.921 Y3.112
G1 Z-0.5 F400
G18 G3 X40.921 Z-0.5 I-1. K0.
G1 X37.625
X5. F800.
X0.01
X-0.01
G17 G2 Y11.138 I0. J4.013
G1 X0.01
X5.
X38.
G3 Y19.165 I0. J4.013
G1 X37.993
X5.
X0.01
X-0.01
G18 G3 X-1.01 Z0.5 I0. K1.
G0 Z15.
G17
M30
As you can see I removed the toolchange and particularly the G43 tool length compensation lines. Try it..... well above the part to start with!

Carig

Title: Re: X and Y Alignment
Post by: BluePinnacle on May 09, 2018, 09:55:15 AM

I stayed in Akaroa a few years ago, it's a lovely area.
Back on topic: I don't think I've ever used MDI. I'm making a new screen set and I may leave that page out altogether.