Alarm 5: Probe did not contact the workpiece

[johnvolbeda]

I am using the Autoleveler plugin with an X, Y,Z touch probe and get this error shown in the title. I load the file and select Use Loaded File. The Min and Max values for X, Y and Z auto populated and I do not change these values. I understand the purpose of the Resolution settings.

The level probe stops short of the material. Part of my problem is that I do not know what the settings should be for the following parameters:

Gcode Z surface
SETTINGS TAB:
Z Height of probe surface in gcode
I assume the Probe X, Y and Z offset are zero since I move the touch probe directly over the material and then reset X, Y, and Z.

Any help or guidance is appreciated.

FYI, I am engraving text on a 1 inch diameter acrylic convex disk and need to scan the surface and apply the contour to the Gcode so the engraved depth will be uniform on the disc.

[breiler]

There has been a lot of fixes and adjustments to the autoleveler module lately. I'd recommend the latest freshly baked version from here: https://github.com/winder/Universal-G-Code-Sender/releases/tag/v2.0.20

I have tested probing on this version quite thoroughly but there is always a risk that I have missed something. So if it is possible be careful when initiating a probe.

When you use the Use Loaded File to get the model size it will set the probe area to the exact extent of the model. This usually means that you will never reach material with the probe. Manually set the Z min to be slightly under the surface material.

The Z Retract will now be displayed as percent in the latest version, leave it to 100% to begin with. By lowering this you can speed up the probe process, but if you are not careful it could cause the bit to scratch the surface of the material.

[johnvolbeda]

Thank you for the review and reply. The probe starting position is just above the material. When I change Z retract to 100% and Z max to 0.5, I get the following error: An error was detected while sending 'G38.2 Z-1 F0.394': (ALARM:4) Probe fail. Probe is not in the expected initial state before starting probe cycle when G38.2 and G38.3 is not triggered and G38.4 and G38.5 is triggered. Streaming has been paused.
ok

I attached a screen shot and hopefully you can see it and the end of the run with the error.

I value your time and expertise.

[breiler]

OK, I see the likely cause for the problem. The gcode is in inches and you are using millimeters in the UI. The probe settings should therefore also be in millimeters. But something is clearly not working as your probe settings are intepreted and vizualised as inches.

I am almost certain that I have tested this scenario, but apparently I have missed something.

Until I find a fix for this problem, is it possible to regenerate the gcode in millimeters?

[breiler]

Or set the units to inches in the UI if that is your preferred units:

[johnvolbeda]

Thank you so much for noticing. Of course, I will try both to (1) change the units to mm to generate the gcode and later on (2) change the units to inches in UI. Please stand by ....

[johnvolbeda]

Good morning. I tested various options: (1) change the units of the gcode to mm and set the UI to mm. (2) Change the units in the UI and used the gcode generated in inches. I changed to values of Z Min, Z Max, Z Retract to various settings and all of them result in the probe not touching the surface of the material. The error code is: An error was detected while sending 'G38.2 Z-7.1 F10': (ALARM:4) Probe fail. Probe is not in the expected initial state before starting probe cycle when G38.2 and G38.3 is not triggered and G38.4 and G38.5 is triggered. Streaming has been paused.

I did notice than when the Z Max value is lowered to .01, it brings the end of the probe closer to the material, but still not enough to make contact with the material.

I believe we are eliminating variable and am sure we are getting closer. Let me know what other information you would like.

I inserted a screen shot in the next block.

Thank you in advance.

[johnvolbeda]

[breiler]

From this log it looks like it just sent the command for the first probe command and complains that the probe was already triggered from start.

Was "ALARM: PROBE" active before you started probing?

[johnvolbeda]

Thank you for your quick reply. It is probably my ignorance on the operation of many of these features. But yes, the ALARM: PROBE is energized on start up. I also checked into the GRBL documentation and says the following:

$6 - Probe pin invert, boolean
By default, the probe pin is held normally-high with the Arduino's internal pull-up resistor. When the probe pin is low, Grbl interprets this as triggered. For the opposite behavior, just invert the probe pin by typing $6=1. Disable with $6=0. You may need a power cycle to load the change.

$6=0 but when I changed it to $6=1, the ALARM: PROBE is de-energized. After adjusting some of the AUTO LEVELER settings, I can now for the first time probe the convex surface!!! I will insert a screen shot of the finished part. Tomorrow, I will do some more testing but I think that with your great help and patience, I just might be able to move forward and engrave on a convex surface. More soon and then we can close this out!

[johnvolbeda]

[breiler]

Cool!

There are some obvious fixes that would have improved the user experience, for instance:

• You should not be able to start probing if the probe is already active
• Display the units of the settings
• And have a look at the bug that didn't properly update the settings

[johnvolbeda]

After some more testing, it appears mixing of inches and mm units between the Gcode generated by F-Engrave and UGS UI could be confusing to the operation. I had success when the Gcode was generated using mm and setting the UI to mm. After scanning the part, applying the result to the Gcode, installing the router bit and setting zero in the center of the part and sending the code, the starting point of the tool path is at the bottom left side of the letter "O" in my text. However, the origin in F-Engrave is mid center. Since this is a convex shaped part, the bit does not touch the part. This is confusing to me and not sure how to correct this. (I did not close this discussion since this may still be related to the AUTOLEVEL feature.) Your expertise is greatly appreciated.

[johnvolbeda]

My apologies for not providing an update on my issues. This has totally been resolved and the AUTOLEVEL feature indeed works wonderfully! Thank you so much for all your efforts and keeping this great software available. We appreciate you!

[johnvolbeda]

This has been resolved and is closed!