I am running Mach4 4.2.0.4300 Build 4300 and Pokeys 57E 8.38.0.3630 on a mini lathe with an old Win 7 PC. The control and motion device parameters are the same as years ago. I checked against a doc I had made.

My X tool offset kept changing. I finally noticed that the Y stepper was jerking / not turning smoothly on a facing cut. It used to work fine. But that was quite a while ago as the machine was gathering dust. I pulled the belt and observed the stepper by itself. Still jerking on a simulated facing cut. I swapped X and Z cable on the outputs of the CNC4PC box. Now the Z was jerking. Both motors are config'd Velocity 70 Units/Min and Acceleration 20 Units^2.

My question, where would the collective wisdom of the group suggest I look next. Hardware like swapping drivers in the CNC4PC box, or messing with software, possible upgrading the Win 7 machine. I was thinking of upgrading the Win 7 hardware and Mach software anyway. I would like to not introduce too many variables.

I had tried upgrading to the latest Mach4 and encountered problems. I re-imaged the PC with a good know backup  to get back to where I was. An issue developed with path errors. See attached. The path and file is there. So I am scratching my head. IF I say OK and dismiss. System will run the Gcode. But I get the "missing steps on X, but not Z. If there was a big problem, I'd expect both X and Z not to work.

Thanks,

Dale

Hi,
I very much doubt that its a problem with your PC or Mach. The fact that you transfer the cable and the fault follows the cable suggests that the stepper driver is faulty.

Whatever you do.......don't do a scatter gun approach, it seldom works and more often than not you introduce a second problem and that becomes very VERY much harder
to diagnose. Try swapping the stepper drivers between axes. If the fault follows the driver, then the driver is faulty.

Craig

I swapped data cable inputs to the X and Z motor drivers. Problem was on Z.

Hi,
you say the data cable?

Have you trued swapping the stepper drive. I rather suspect the fault is the stepper drive rather than mach or the PC, but you need a test
to confirm that. I'm not sure that swapping the data cable adoes that.

Craig

Thanks Craig - you made me think.

I restored a backup to this Win 7 machine from several years ago when it used to work. Still had erratic X drive behavior. I physically swapped the motor drives. Problem stayed on X. Arturo with CNC4PC suggested I use a different axis. Since this is a lathe, I configured Y, Motor 1, to the X axis. Still had the problem. Interestingly, jogging is smooth. Only when I run my Gcode do I have jerky operation. So I abandoned my Gcode and used the canned facing program included with Mach. Xi @ 0.5, Xf at 0. Zi at 0, Zf at -0.1. Posted to Mach4, jerky X operation still there. Power Supply???

As background, used to work several years ago. Mach4 4.2.0.4300. Pokeys version, I don't know anymore.

Thanks,

Dale

I believe I have a working system. There are some config tweaks that need to be addressed. Spindle speed input is not working. I'll look at my old config.

Installed Mach4 version 4.2.0.5036 on a re-imaged 8 year old win 10 laptop. Abounded my old slow Win 7 desktop
Installed M4_M16D_LATHE Beta_V2.0.0.0.zip

Dale