Mystery stopping of PRT, crazy restart!! Help

[Chuck Keysor]

Hello Shopbot Friends:

In cutting out a previously posted flower image from an 8 foot long, 12" wide 3/4" PVC board, I was maybe 15 minutes into cutting with a 1/4" bit, when the Bot stopped. The screen display was flashing, and the error message said: "!!! TOOL STOP BUTTON ON!!!".

Well, the button wasn't pressed, I was just glancing that way, when the BOT stopped. I wasn't vacuuming, or even moving.

So I went to the PC, and it told me that the cut file had stopped at line 4738. I figured that instead of restarting the file from the very beginning, that I would see if I could figure out how to make the file resume where it had left off. (I hadn't touched or moved anything on the Bot since it suddenly stopped. The spindle was sitting right where it was when the Bot stopped.)

My BOT cheat sheet led me to the FG command. It asked for a line number, which I entered. Then it asked me if I wanted to resume from that point, or if I wanted to single step. I selected resume, then hit the start button, and in 20 seconds, the spinning bit plowed into the flower and cut a 1/2" groove in the WRONG place, before I hit the STOP button. (Where it cut, was not even a logical place, compared to the following error.)

So, I hit myself in the head, and said I should have just restarted from the beginning, instead of trying to be cleaver!

After restarting the SB3 control PC interface, I reloaded my original file from the flash drive, and hit start. In maybe 15 seconds of starting, the spinning bit cut into something that it should not have. (It was cutting in the right place, but was cutting maybe 1/4" too deep.)

Questions:
1) Why would my Bot suddenly stop, claiming that the Stop Button had been pressed when it had not been pressed? (I don't think I have ever had this happen before. But I have occasionally had my Bot stop when it said I had exceeded the table limits when I was nowhere near. In those cases, I was given the choice of continuing or not, and it worked fine.)

2) How should I have restarted the cut file from where it had mysteriously quit?

3) Why would things get fouled up after RELOADING my cut-file? (This is the most troubling of these mysteries! I had this would be a sure fire way to get back to normal.)

Thanks, Chuck

PS: I had already run this cut file on an identical board yesterday, without any problem.

[jerry_stanek]

Did you transfer the file to your desktop or did you run it from the flash drive. Never run a file from a drive other than the control computer's

[Gary Campbell]

Chuck...
Answers:

1) Most likely answer is static. There are volumes posted here on solutions
2) Once you reset axes zero, you should be able to restart from any place you select. Numerous posts here on how users accomplish this operation
3) Not quite sure what you mean by "reloading". If the first version was not corrupted, then nothing can be gained. Most likely cause for second failure is static, same as the first.

[Chuck Keysor]

Thanks Jerry and Gary for your replies.

My design computer is upstairs, and when I create the "cut files", I save them directly from Aspire on a USB flash drive. I bring the USB flash drive down to my basement, plug it in to my Bot's control PC, and using SB3, load the cut file directly from the flash drive. That is how I have always done it without previous problems.

After everything went wrong yesterday, I removed the flash drive, completely shut down my control PC, and the Bot. I restarted it all and reinstalled the flash drive in the control PC, and loaded the cut file.

As soon as the Bot began to run, it did not correctly execute. The bit retraced the same wrong path it did when I first restarted after the original unexplained halt (where I used the "resume at line" option. So it looks to me like the file on my flash drive has been corrupted.

I should have re-saved the cut files from Aspire onto my flash drive by now, to see if that fixes things, but I got tied up. I'll post as to what happens tonight.

Thanks, Chuck

[Chuck Keysor]

I just now looked at the first 25 lines of the file from my USB drive that had been used to run my Bot yesterday, and compared it to a new cut file I just now saved from Aspire, and I don't see any difference. (Of course it made no sense technically that a corruption could have happened in my USB file.... but based upon behavior of the Bot, it seemed logical.)


Chuck

[scottp55]

Chuck,
Download the file from the flashdrive to the control computer, and EJECT flash drive.
Run file from control computer.
What happens then?
scott

[Chuck Keysor]

Thank you Scott for your reply. Sorry I was slow to reply, but I had family visiting from out of town.

I went to my shop to try your suggestion. But first, I decided to remove the bit, and re-run the entire cut file just as I had done before, hoping to figure out what was going on, without further hacking up my project.

It quickly became clear, that whatever caused my cut file to suddenly stop, and issue the spurious message "!!!Tool Stop Button On!!!!", OR my attempt to resume the file where it had been interrupted, also had messed up my Z-zero point. As an estimate, the bit had been cutting about 1/2 inch too low when I first tried to re-run the entire cut file, causing the bit to rip into places it should not have.

So I reinstalled the bit, and re-zeroed it. Then when I executed the entire cut file, it ran fine.

But why my Bot stopped in the first place (issuing the false "!!!Tool Stop Button On!!!!" message) is still a mystery. Static would be the most likely event, as it is so random. But my basement has lately been cold and damp, due to rain, and the fact I haven't turned the heat on yet. And I don't have a dust collection system, which is a famous way to generate significant ESD events. And it wasn't yet Halloween when this happened.

So for now, I'll have to just keep watching out for a repeat performance of this situation.

Thanks again Scott, Jerry and Gary for your time and thoughts. Chuck

[rb99]

My thought on the error is using the USB drive. With my 4g controller I need to use a USB hub (supplied by SB) to prioritize that USB port over the others. I bet using the USB flash drive messed with the spooling.

[Mayo]

Chuck, I've had PVC "snow" build up on my table limit sensors and trigger one (presumably from static).
But if I remember right, you don't have those sensors?

Another thing that messes up my control box and cutting is when my air compressor kicks on when my control box is on. Even though they're on different circuits, it causes errors like missed steps or incorrect Z location.

When I remember, every time I turn the control box on, I shut off my air compressor switch so it doesn't cycle on when it needs air. If I forget and it turns on, two things can happen - 1 is I get lucky and the currently running file will finish with no problem. I suspect this may be related to how much info is in the currently running buffer and if the timing of sending new data to the buffer happens when the compressor kicks on.

2 is the steppers may miss steps and the job gets messed up. In the case of the file finishing OK, I have wound up with the bot thinking it was located where it actually wasn't located, including the Z being incorrect. The only solution for me in either case is to shut off the control box, wait at least 30 seconds, restart the control box and re-zero X, Y, and Z.