(Solved) G43 not being applied in g-code

Revisiting an issue I noticed here:

forum.linuxcnc.org/10-advanced-configura...l-orientation#345715

At the time I wasn't sure if this was a GUI issue, or something in my config.  I've since switched GUIs (Axis, FlexGUI, and Qtpyvcp) and the issue is the same across all three GUIs.

Problem I have is that G43 isn't being applied consistently during a program.  G43 works via MDI, and all three GUI tool-change buttons.

I've tried every permutation:
Tn M6 G43
Tn M6 G43 Hn
M6 Tn G43
M6 Tn G43 Hn

And the same as above, but with G43 on another line.  Also tried an M1 after the tool change line(s) - even a few lines down - but LCNC just isn't applying the tool offset.

When I run a program, LCNC excutes the tool change - new tool number is displayed in all three GUIs - but doesn't apply the offset.

Tool number doesn't matter - whatever tool offset was previously applied remains active after the Tn M6 line.

Under Axis I was using the "T" remap from the sim lathe-fanucy
Under qtpyvcp, I commented out the "T" and "M6" remap and was just using the 'stock' M6

I'm sure this is something on my end and unlikely to be an LCNC problem.  Maybe the remap.py and stdglue.py used by my other remapped M-codes is interfering with 'normal' M6/G43?

Anyone have an idea what would interfere with G43 being applied during a program, but not via MDI or a GUI-based command?

Do you have a sample program that uses the G43 call?

andrax wrote:

Do you have a sample program that uses the G43 call?

Not handy at the moment, but the issue persists across multiple programs.  First noticed on a fairly simple turning pgm with 3 tool changes, but the same thing happens when I just hand code or trim down a pgm for testing.

I can double-check for something abnormal later, but is there something I (or the post processor) could put in a program which would cause LCNC to ignore G43?  It's not like there's a GOTO statement skipping over the G43 words.

Please try to provide a program excerpt. I would like to take a look at it and test it on my system.

Here's a program snip from the last round of unsuccessful testing:



As I mentioned earlier, I've also tried the G43 on a separate line, with and without the Hn word.  I added the M1 just to stop the pgm before the spindle ramps up during testing.

The X-values are all negative based my post processor (gang tool slant bed back-lathe, X+ is 'up', and T2 is on the 'negative' side of things).  The motion is correct for my particular setup.

If I start the above program with T2 loaded and offsets applied (via MDI or GUI cmd), everything works...until the next tool change.

I've also attached my remap.py and stdglue.py just in case there's something in there messing things up.

Thanks for having a look.

I see
G53...
G43...
G54...
G43 currently refers to the machine coordinates. Then you select coordinate system 1.
That might be why G43 becomes ineffective.
Write G54 before G43
G53...
G54...
G43...
In MIDI, by the way, the last coordinate system is always active, so G54.

I hope this helps

regards

I was under the impression that a 'G0 G53 Xnnn' line doesn't change the active WCS to the machine coordinates, it just causes LCNC to move to a machine coordinate for that line only.

Second, if a change in WCS causes the tool offsets to be removed everyone using LCNC would have to write programs with G43 after every WCS change.

More importantly, the order of G53-G43-G54 is what is output by the Fusion 360 standard LCNC turning post.  I can't be the only one using that post; if that order was wrong everyone who uses the post would be having the same problem.

I will certainly try out your suggestion this evening even if I'm dubious.  And thank you for giving it some thought.

I'm not entirely sure about this either.
At least G10 only affects the currently selected coordinate system. As soon as you switch, your shift disappears.
It could be the same with G43, since you're applying the length correction to G53.

Just try it out.

You can check for G43 in Linuxcnc status. Eg Axis:


 


M6 turns off G43, 
so G43 in a line with M6, sets G49