Mach3 control loosing zero

I've had my KX1 for thirteen years now, it was one of the early imports as the serial No. is 1/09/0044 I've always been okay with machining and programming but when it comes to the control Its been a bit of a closed book. I'm pleasantly surprised that I've come this far without any serious issues, but over the past couple of weeks proven programms have either stalled or the control looses its bearings and sends the cutter on a walkabout. I have also had the cutter over shoot its home position when returned to zero. I expect that perhaps thirteen years of use is about as good as it was intended, but now buying a new machine (even if I could afford it) would mean an import from The People's Republic. So, my question is: are there any fairly straight forward diagnostic steps I could undertake to establish the source of the problem and if mechanical or electronic is there are source of replacement parts. Thanks in advance.

Edited By mick on 22/01/2022 17:10:06

Have you cleaned, lubed and setup the gibs/ slide ways?
Sounds like sticking slides

Not having one shot lub I tend to use an spray lubricant on all the slides before I start machining, but I've never stripped down and cleaned the slides, so now could be as good a time as any. Thanks for that bit of advice. Do you speak from experience?!!!

My little CNC is quite sensitive to slide lube. It could do with higher voltage drivers / more powerful steppers, but instead I’m building a new one…

13 years of is long enough for oil to congeal in the inner workings. I can remember if they are ball screw, but the nuts on it could probably do with cleaning and lubing

Dave

Make a copy of your .XML and .DAT files into a new folder, rename the Mach3 folder something like "Mach3 old" and reinstall Mach3. Then copy the .XML and .DAT files into the new install. Sometimes Mach3 files get corrupted and cause all sorts of odd things to happen and this is the easiest way to rule this out. If it makes no difference you still have the original Mach3 folder to go back to if necessary.

Martin C

• What do you mean the "home position" that it overshoots? Is this the one it goes when you click "ref all home"?
  
• Could you give an an example of a "walkabout"? Is it overshooting or not moving as far as expected?
  
• What is the symptom of a program "stalling"? Does it give any error message?
  
• I'm very familiar with Mach3 but not the X1. What is the connection between the controller and the machine (i.e. the stepper motors and limit/home switches? If it's a multi-way plug and socket have you tried wiggling it or unplugging/re-plugging it?

My little Denford's controller which I built is ~10 years old, and the machine itself is a lot older and it still works fine. I doubt there will be wear problems with the KX1 mechanics but it is of course worth checking the gibs, slide lube, etc, but something like this going wrong quite suddenly strongly suggests an electronics hardware problem. I once had an issue where the Z axis would only feed down whatever way the controller said - turned out to be a wire had come adrift from the direction input on the Z axis drive. If the worst comes to the worst, the electronics is not too expensive to replace and modern stepper drives are significantly improved.

Something similar happened on my Emco VMC cnc mill.

After days of checking the software and electronics it turned out one of the axis connections to the stepper motor pulley had worked loose. It was still engaging but intermittently.

Also had a similar problem once when the leadscrew nut became a little loose on the slide.

Both mechanical issues and relatively easily fixed.

Mach3 is excellent, but it only counts steps, not actual locations!

John

I use Mach3 on my router and Engraver, but cannot remember where the motor setups data is stored ( acceleration and max velocity settings) . Is it in the .DAT file? . Stalling is either binding slides/leadscrews or those motor speeds and accels data got corrupted - I think the latter is unlikely - I have never had Mach3 itself become corrupt, nor its setup files, not in 19 years of Mach3 use...

Going past the home position is most likely the home position sensor feedback is not happening - broken cable, microswitch, connector, etc? You can look in the Mach3 diag page at the switch sensors and jog the axis to the home position - you should see the sensor 'led' light up ( or go out, if sense is reversed..)

The cutter 'going walkabout' is difficult to comment on - that means little...

If a stepper looses steps during the machining cycle ( bad accel / velocity values, or binding as mentioned) then the cutter will be in the wrong place when sent off to do the next Gcode line, so may appear to be walking about...

There are checks you can do, but you do need to be familiar with how Mach3 works, how to enter MDI commands, how to view the diagnostic page, etc. Are you? If so I am happy to try assist you in checking your setup. If not, I am happy to try get you familiar with it all first!

Joe

Setups are in the XML files. I and others in Mach3 groups have had corrupted files that had to be re-installed due to weird happenings.

Martin C