Last week I had my mill stop responding properly. It was doing a helixcut down a pocket and the z and the y axis stopped moving. So I tried to get the Z up and it wouldn't move. Restarted and the z would come up but the y moved with it! Acted crazy after that so I got a new bob from John and got it wired up. Now I had an issue with y moving in one direction and not the other. Went to the back and low and behold one of the cables from the bob to the stepper driver was not clicked completely. So I did a dry run and everything seemed ok. Did the cut and the z stops moving while doing a peck drill. Didn't realize it until it broke the bit. Then I tried to move the y and it studdered really bad and made a racket and wouldn't move. So I restart everything and make sure all the cables are clicked in and everything seems to work. So I do another dry run and this time let it do the full cycle. I first rezeroed everything so it would be easy to tell if it messed up and right when it was finished and it was going to home it made a quick noise like it was slipping. The x and y at that point were off by 100-125 thousandths. Now I am assuming it was at the end of the cycle when I heard the noise, but can't say it for sure. I took the y axis covers off an found chips in there (bad!) so I cleaned it all out and re-lubed everything and both axis seem to move nicely. Actually seemed smoother than before.
Since I have replaced the bob, I can only assume that the issues have to do with the computer or the drives/steppers. Since it is happening on a random axis, I am thinking it is the computer. Right now I am running through the parallel port to the bob. I have a smoothstepper I can install. I am thinking if there is something wrong with the parallel port, moving over to the smoothstepper could cure it. Long shot I know, but I don't have another computer I can hook up to test it that has a parallel port.
To recap:
Random axis will stop working and then work fine (with no noise)
Makes "I'm stuck" noises when it shouldn't be stuck
Mach always thought the axis were moving
Before even this happened sometimes moves were not fluid. Seemed like there was a very slight pause in between g-code commands. Very noticeable when doing helix cuts. Restart of mach fixes this.
I assume the "I'm stuck" noise is some sort of slipper. Can I adjust this?
Any help would be greatly appreciated. I have so much work to do and am getting backed up by the day...
Thanks - Keith