Machsupport Forum
G-Code, CAD, and CAM => G-Code, CAD, and CAM discussions => Topic started by: wdwkr53 on July 08, 2014, 11:34:59 PM
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I am suddenly having X-Axis missed steps issues. I tore down the X-Axis to check for problems, I swapped stepper motors, I changed outputs between X & Y axes on BOB, but it still misses steps on the return to zero. I slowed the motor tuning settings to 100 ipm. I lowered acceleration to 5. I turned off tool path view. I changed the parallel cable. I tightened all screws on electronics. I am rastering a 6"x26" dome-shaped object and it started missing steps on the return leg towards zero on every pass - thus making a parallelagram. Then it would go fine for 15 minutes & suddenly loose a bunch of steps and be off by 1-2 inches as if a lot of skipped steps. I have been repeating the same program dozens of times, & it fails in different spots each time now. The last time it was on the return leg to zero on X when it stopped X travel, suddenly rose about 2-3" on Z, moved on towards zero, then lowered back to surface.I stopped the program & it thought it was 2 inches further down the X Axis. I checked gcode - the endmill was not where the gcode said it should be. I was as if the gcode kept moving in the X direction while the mill was moving in the Z direction up & down. The errors are so random, I am thinking about getting a different BOB next. I am running ssd computer with WinXP Mach3 R3.043.066 for some time now without problems. Any suggestions would be greatly appreciated.
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Hi Marv,
Pretty ugly problem you are describing, it could have many causes but I would be inclined to make a clean re-install of Mach3 (possibly an earlier version .056 ?) and see if that resolves the issue. Don't forget to back-up your Mach3 folder so you can copy all your settings etc. to the fresh install.
Tweakie.
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So today I loaded Mach....062 in place of ....066 & it failed. I switched to a Win7 machine with usb-to-parallel cable & it failed. I changed out the BOB & it failed. I connected X-axis motor directly to controller & it failed. I switched X & Y controllers & it failed. I'm done for the day, but wondering what is left. X-Axis motor? The program fails in different places in the code each time. Any other suggestions?
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Hi Marv,
If you have swapped stepper motors then it is unlikely that the problem lies with the X axis stepper.
You could try reducing your Velocity and Acceleration settings further and see if that makes an improvement.
Perhaps a silly suggestion but I trust you are using a genuine Mach3 license ?
Tweakie.
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Your motors may be fine for 2 D work but lack the power for 3D work.
Reduce your velocity and acceleration and see how it goes.
RICH
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I spent a lot of time tacking down the problem, & turns out the X-Axis coupling was the culprit. I had changed from LoveJoy spider type to a split type quite some time ago. I checked it when I tore down the X-Axis and went on to other possiblilites. After rewiring, swapping BOB, slowing down tuning, etc. it got worse & just sat in one spot on X & went up & down on Z axis. I checked the X stepper & noticed the motor turned but not the lead screw. The set screws were tight on the coupling but slipping. It is some kind of plastic. So I went back to LoveJoy & it works fine now. I ran the same job twice without a hiccup. I guess lesson learned is don't give up and don't assume - recheck what you already checked! Thanks so much for you assistance.