Error: Program Exceeds Machine Maximum, but gcode looks fine

More
04 Jun 2023 16:58 #272887 by re_relentlessly
I am getting an error while trying to run my gcode (from fusion 360) where linuxcnc (2.8.2) claims that the gcode exceeds the machine maximum.
But when I look a the preview, none of the depicted gcode exceeds the limits.
I have provided screen shots with the gcode preview aligned on x, y, z and a perspective view

Is the preview not showing me all the gcode or something? Because I cannot figure out what exactly is causing the "Exceed Machine Maximum"
In the preview I see 79.6mm of total z travel which is within the total z travel.
Note: I don't have a tool loaded in the screen shots because that just ends up offseting everything by the tool offset amount (a different issue I am still trying to understand and resolve)

I have also attached my .hal and .ini, incase it helps debug the issue (if I am not just doing something wrong).
 

Please Log in or Create an account to join the conversation.

More
04 Jun 2023 17:38 #272891 by Aciera
Seems that you have your work offset (G54) set to coincide with the machine (absolute) zero? (ie your preview shows the coordinate system in a corner of your machine limit box).
You should define the g54 offset in relation to your work inside your cad/cam and then touch the machine off on the relevant corner of your work piece after fixing it on the machine.

Please Log in or Create an account to join the conversation.

More
04 Jun 2023 18:45 #272898 by re_relentlessly
Ok, so calibrated the tool (m400 p2 r0) and then touched off a tool (t20 m06 g43) using my tool length setting to re measure the tool length.
I then set the g54 offset again, by moving the tool to the correct spot and clicking "Touch off" for each of x,y,z.
after this proceeder the xyz gizmo was in the corner but z offset by the tool length upwards. I toggled machine power off and then back on. and this reset the gizmo to what you see in the attached screen shot (toggling the power moved the gizmo??)

I do see that the g54 offsets match exactly with the absolute ones.
My machine is set to "Tool touch off to fixture", maybe this is incorrect? or is there something else I have set incorrectly?

I do have g54 set to a corner of the work in my cad/cam (fusion 360), and I do move the tool tip (or a edge finder ) to the matching corner of the work and the use the "Touch off" button in the linuxcnc ui to set g54 (on x,y,z)
Attachments:

Please Log in or Create an account to join the conversation.

More
04 Jun 2023 19:13 #272901 by Aciera
Have you checked the offsets in your tool table?

Please Log in or Create an account to join the conversation.

More
04 Jun 2023 19:23 #272902 by re_relentlessly
I have attached a screenshot of my tool table. All my tools have positive z offsets. should they be negative?
Attachments:

Please Log in or Create an account to join the conversation.

More
05 Jun 2023 05:48 #272930 by Aciera
Tool table looks ok.

I have never used the "Touch off to fixture" setting but it might be worth a try to switch that to "touch off to workpiece".


Tool touch off to workpiece - When performing Touch Off, the value entered is relative to the current workpiece (G5x) coordinate system, as modified by the axis offset (G92). When the Touch Off is complete, the Relative coordinate for the chosen axis will become the value entered. See G10 L10 in the G code chapter.

Tool touch off to fixture - When performing Touch Off, the value entered is relative to the ninth (G59.3) coordinate system, with the axis offset (G92) ignored. This is useful when there is a tool touch-off fixture at a fixed location on the machine, with the ninth (G59.3) coordinate system set such that the tip of a zero-length tool is at the fixture’s origin when the Relative coordinates are 0. See G10 L11 in the G code chapter.

Please Log in or Create an account to join the conversation.

More
05 Jun 2023 20:40 #272974 by re_relentlessly
switched over to  "touch off to workpiece".
that didnt fix the problem (that is assuming that the behaviour I am seeing is even a problem??)

I homed the machine, ran the calibration (m400 p2 r0), loaded a tool and measured its length (t20 m06 g43), loaded the gcode.
Then I set the g54 offsets via "Touch off"
As visible in the attached images. the x,y,z gizmo is now offset in z, but still aligned in x,y.
The error is now in both directions on z.
And the gizmo offset has made the total travel requirement longer.

To help me understand what is going on, can you (Aciera) or anyone else confirm that the behaviour I am experiencing is incorrect/wrong?
and what is the correct behaviour?

Because I really don't understand what is happening, why the gizmo offset's when loading a tool offset.


 
Attachments:

Please Log in or Create an account to join the conversation.

More
05 Jun 2023 21:26 #272976 by MaHa
Your Z axis setup ist strange
MIN_LIMIT = -0.01 MAX_LIMIT = 200.0

Most machines are configured with Z machine zero full retracted
MIN_LIMIT = -200 MAX_LIMIT = .001

I think some cam can´t handle your Z config properly. In case you do G0 G53 Z0, the tool is crashing your work, so it´s better to have machine zero retracted

Please Log in or Create an account to join the conversation.

More
05 Jun 2023 21:56 #272979 by re_relentlessly
Maha : interesting. The way I have it configured, z all the way up is Z 0, and it goes negative as it moves towards the table. I was under the impression that this was the "correct" or standard way to set it up. 

Please Log in or Create an account to join the conversation.

More
05 Jun 2023 22:20 #272980 by MaHa
I tought MIN_LIMIT is Z full extracted, as a minus value. Maybe i´m wrong. Did you try carefully where the machine goes with G0 G53 Z0 ?

Please Log in or Create an account to join the conversation.

Time to create page: 0.123 seconds
Powered by Kunena Forum