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Author Topic: Mach3 Axis Calibration Mystery  (Read 10121 times)

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Re: Mach3 Axis Calibration Mystery
« Reply #10 on: February 28, 2017, 10:21:06 AM »
Quote
However, when i click the GO TO ZERO, the X-axis is moving to its ZERO at a far higher speed than I can obtain by the motor tuning without the motor stalling? What is the explanation for that? Of course if I could imitate the tuning that the Mach3 is using for the GO TO ZERO command, then I'd be much better off speedwise...

Hi Anders,

I have no explanation for that but remember that accuracy and reliability is far more important than speed so don't go setting your Velocity too high.  ;)

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Mach3 Axis Calibration Mystery
« Reply #11 on: April 09, 2017, 04:12:11 PM »
Hello again,

I don't know if I can rely on that this thread is alive?

Anyway, I'll post and see.

I now have a software problem. I am using CAMBAM for CAM programme. And visually in the cam window, my design makes absolute sense, a number of logs cut-out from a 2440 x 1220 cm sheet.

Anyway I generate the gcode, loads into Mach3, and my design is in the middle: a lot of crazy arcs starting from either end of the sheet and looping to the other end in immense proportion.

By google, I have come across threads that almost exactly describes my problem, and relates it to the Distance mode / IJ mode:

CAMBAM is set to IJ Incremental C-P1

Mach3 is set to Distance mode: absolute and IJ mode incremental.

And I have spent the whole day doing anything in between, typed G91.1 in the MDI in Mach3, in CAMBAM switched from Incremental to default & postprocessor to Mach3, restarted programmes, updated settings etc.: STILL, those crazy loops!

I really hope that someone can help me out here,

best regards

Anders

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Re: Mach3 Axis Calibration Mystery
« Reply #12 on: April 10, 2017, 01:24:29 AM »
In Config. General Config. change the JI Mode
then Regen. the Toolpath Display.

Ideally your Gcode should always contain the G90.1 / G91.1 as appropriate.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Mach3 Axis Calibration Mystery
« Reply #13 on: April 10, 2017, 08:02:38 AM »
Hello,

I have tried to do as you say, go to Config > General Config, change the IJ mode from Incremental to absolute and vice versa, whenever those loops appear. And after each swapping regenerated the toolpath window, to no avail.

The gCode of CAMBAM is set to default... here's the prologue in the beginning of the gCode string. With a gCode, like that should the IJ mode be incremental or Absolute, and should the Distance mode be Inc or Absolute?

( Made using CamBam - http://www.cambam.co.uk )
( WOODWAVY SECTION 1B R12 NAT 3 CAMBAM singular 2 4/10/2017 1:47:43 PM )
( T0 : 0.0 )
G21 G90 G91.1  G40
( T0 : 0.0 )
T0 M6
( WOODWAVY SECTION 1B R12 NAT 3 CAMBAM singular 2.nc )
( Made using CamBam - http://www.cambam.co.uk )
( WOODWAVY SECTION 1B R12 NAT 3 CAMBAM singular 2 4/9/2017 10:23:03 PM )
( T0 : 6.0 )
G21 G90 G91.1  G40
G0 Z3.0
( T0 : 6.0 )
T0 M6
( Profile2 )
G17
M3 S1000
G0 X4.9207 Y1153.611
G0 Z1.0
G1 F300.0 Z-0.4
G1 F800.0 Y1135.4444

Do you have any other ideas?

best regards

Anders

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Re: Mach3 Axis Calibration Mystery
« Reply #14 on: April 10, 2017, 08:17:19 AM »
Exactly the same idea.

You Gcode is putting Mach3 into the wrong mode. Delete all the occurrences of G91.1 from your Gcode and replace them with G90.1

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Mach3 Axis Calibration Mystery
« Reply #15 on: April 10, 2017, 09:45:11 AM »
I did as you suggested, and now I get "radius to end of arc differs from radius to start", but at least the loops disappeared from the Toolpath screen., hehe.

By looking around I've gathered that this is Mach3s expresion in words of the IJ mode problem?

I also have a yellow button on the mach3 screen bleow the Toolpath screen that says: "Abnormal Condition". When I click it says:

"One or more axis are enabled or disabled
IJ mode is absolute
Currently in metric units"

Does this say you anything?

best regards
Anders
Re: Mach3 Axis Calibration Mystery
« Reply #16 on: April 10, 2017, 11:02:13 AM »
I wish to add that if I
1) change every line with the G 91.1 (there is but one) to G90.1, and
2) ensure that the General Config > IJ mode : Absolute,  then Mach3 tells me "Radiius to end of arc differs from radius to start", - however this message seems to block Regen Toolpath, so I cannot 'see what's wrong'.

And if I
1) change the general Config > IJ mode to Incremental
2) change the line G90.1 to G91.1 in the gCode made by my CAM programme  (that's actually the default mode of my CAM programme), I get crazy loops.

From your experience, is it possible just to swap between G91.1 and G90.1 in both the Gcode and the Mach 3  General configuration, and that's all there is to it?

best regards

Anders

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Re: Mach3 Axis Calibration Mystery
« Reply #17 on: April 11, 2017, 01:03:54 AM »
Hi Anders,

Just swap G91.1 for G90.1 in your Gcode - that's all you need to do.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Mach3 Axis Calibration Mystery
« Reply #18 on: April 11, 2017, 04:35:59 AM »
Hi Tweakie,

I am afraid that just to swap G91.1 for 90.1 in my Gcode will not make it work.

As I wrote in my last post, doing that makes Mach3 say "Radius to end of arc differs from radius to start", and seemingly there's no change to the crazy loops toolpath.

I had this from a different source:

"That definitely looks like the wrong IJ mode to me but you are really the only that can say for sure. I also wonder if there was a G2 or G3 that wasn't canceled when it should be?

Neither the distance mode nor IJ mode setting in Mach3 general config will make any difference (a G90, G91, G90.1 or G91.1 executed through Gcode overrides their relevant settings in general config) at all as long as the Gcode sets the correct mode as needed. Which it should because the Gcode is what determines what the right mode is. Well, ultimately that decision comes down to the programmer (the one writing the Gcode) and what they want the machine to do."

Can I ask you about this? If the CAM programme Gcode overrides Mach3 settings then changing the G91.1 for G90.1 in the Gcode would give the outcome that Mach3 changes it General Config> IJ mode setting. But how can I prevent Mach3 from making the crazy loops if I cannot change Mach3's "reading mode" of the Gcode?

best regards

Anders   
Re: Mach3 Axis Calibration Mystery
« Reply #19 on: April 11, 2017, 04:53:41 AM »
Here's also what:

I changed the Arc Center Mode setting for the MOP in the CAM programme to Absolute, then generates Gcode from the design, and loads it into Mach3.

In Mach3, the General Config > IJ mode is changed to Absolute, all by itself. But still those crazy loops.