Bug in stopping an M6

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Bob Z
Posts: 10
Joined: Tue Jul 23, 2019 11:10 am

Bug in stopping an M6

Post by Bob Z » Tue Jun 08, 2021 3:39 pm

Today I was trying to set up a tool and had an issue during the M6 process, as the tool was dropping towards the touch plate, so I hit the stop button. Previous to 1.0, if I did that, the system simply stopped. This is the first time having done this after installing 1.0. This time, when I hit the stop button, it interpreted it as an EMO, throwing off my zeros. Even though it showed x and y at zero, in fact, when I reset it and re-did the M6 and ran my process step, it sent the took to the wrong location, where I had to stop it all mid-stream to try to prevent tool and part damage (it was too late on the tool, it was a VERY delicate bit, and broke due to landing in a spot that was far too deep).

The end result was that it stuck in the "jogging mode" (see the recent post that I replied to regarding sticking in jogging mode) so that the controller would not work. The joystick, however, did still allow jogging (although it would not clear the error) and when I moved the part to where the system though zero was, it was dislocated by abuout 10mm to the left (hence the landing the bit in the wrong location).

This may not be clear, so I'll do it as a sequence:

1 - Stopped m6 (zeroing z-axis) midstream (not EMO, I used the square "stop" button)
2 - System interpreted it as EMO
3 - Cleared EMO, but did not move the tool in x- or y-axes. Both x and y showed 0. Re-ran M6 which appeared to work correctly.
4 - Executed process step
5 - Tool moved to wrong location and plunged bit into part (where it subsequently broke)
6 - I stopped the program (not EMO), and it locked me up into "Jogging" mode
7 - I was unable to get the MDI to respond to commands (for exmapl G1X0Y0) as it was stuck in jogging mode, but I was able to use my joystick to move the tool.
8 - I used the joystick to go back to x and y zero, but when it arrived at the spot the system thought was x=0 and y0, it was off by several mm (about 10mm)
9 - I then had to reboot the system to clear the Jogging mode and lost my zeroes completely, losing the ability to accurately cut my part in the process.

Had the M6 stop not triggered an EMO, I do not believe any of this would have occurred. In previous versions I have had to stop M6 on occasion, for example, finding out the bit I was installing was too long to fit (say moving from a 1/8" bit to a longer 1/4" bit) and having to adjust a z-position and restart M6. This has always been fine. Also, hitting the stop button prior to 1.0 has never resulted in a "Jogging" error. I believe the stop button processes has a pretty serious bug or two in it.

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Doug
Posts: 343
Joined: Fri Feb 02, 2018 4:56 pm

Re: Bug in stopping an M6

Post by Doug » Sat Jun 12, 2021 10:30 am

I have partially simulated this, but what I found is that the controller estops if you click 'Pause' rather than 'Stop' during a probing operation (e.g. G38.2 -Z54).

I have opened up github issue #301 on this problem. See https://github.com/buildbotics/bbctrl-f ... issues/301

Note, I also found that this problem pre-dates V1.0.0 as it also occurs in 0.4.15 software.

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