Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: trock on January 08, 2014, 09:00:28 PM
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HI,
I've been running several simple parts on my home built cnc router and have had good luck for the most part. Parts that I ran were great, considering this is a all wood and local hardware design.
I decided to be bold and started a project that was a two sided flip part and it took a long time to cut. I stopped the program and noted what line I was in, all positions and wrote these down so I could
restart the next night. Upon exit it asked to save fixture setup and I said ok.
When I restarted the next evening, all the position values came up as I left it. I loaded the same program and selected the line that I left off at, and selected Run from here. All this worked just fine.
I had another project and tried the same steps and Mach starts up with strange position values. I entered the last positions manually and restarted again at a line I left off. The program
ran just fine from there.
Now the third test was the heart break. I was working on a project with a nice piece of walnut and it was looking good. I had to shut down again and went to restart the next night. Again the positions came up in some weird values way off from where I left it. I again entered values in manually and went to restart from a line like 270192, and selected run from here.
This time the program jumps to the start and then to a line like 190013, and then just gave an e-stop error.
I don't have an e-stop active and no other errors display. I tried this several times with the same bad luck. I was unable to get the program to rerun from the line selected.
Why would I get such inconsistent results. I use a flashcut cnc at work and have never had such erratic results.
Is there something I could look at that might explain this problem? This started off so positive and has now become a real concern.
Grateful for any clues.
Terry
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I have a similar problem, is the the gcode in incremental G91 or absolute G90 coordinates?
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Anytime you stop in mid program, shut off the machine and pc then expect to resume from where you left off at a later time is asking for problems IMHO. In theory it should work but I know from experience the "Run from here" command is not always 100% reliable even under normal conditions. Its best to plan the job where you have the time to see it through to completion. Maybe one of these years Mach 4 will be released and all the quirks in Mach 3 will be fixed. ???
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We'll it's been a long time since I posted this question. Seems like it anyway. Learned a lot reading the forum and need to shout a thanks to you guys/gals that contribute.
I'm running in absolute mode, but all these weird problems seem to have gone away.
I still don't have a lot of luck with "run from here" so I just plan on this ahead of time and leave the machine on until a job is done.
I still don't understand why the start up positions values are all over the place. I just gave up on this and re-zero and go.
I'm very happy at this point and plan to help my daughter build her one now. She's got the bug now after seeing what mine will do.