Triac Z height issues

[andy_con]

can anyone offer any suggestions?

got a triac VMC and its starting to have z height issues. i do a lot of engraving and i set the z to zero, do a 5min job and when its finished its 0.6mm out.

ive done half a turn on the z gib screw but this hasnt made any difference, the screw is pretty tight.

all suggestions welcome.

[andy_con]

so an update

with spindle off and z in the air. if i move x and y around manually z doesnt change.

if i start the spindle and dont touch anything else, the z height drops.

so maybe some interference? .

[m_c]

Sounds like interference is getting into the Z step/dir signals..

Is it still the original spindle?

[andy_con]

Sounds like interference is getting into the Z step/dir signals..

Is it still the original spindle?

yes all original.

its a difficult one to know where to start

[m_c]

Stepper or Servo machine?
Fanuc or PC control?

[andy_con]

Stepper or Servo machine?
Fanuc or PC control?

all original

so stepper and ESS running mach3 (PC)

ive owned the machine for over 10 years now and not had this issue before, had many others. just not this one

[m_c]

Not that original then.

What stepper drivers are fitted?
A photo of the control cabinet would probably be good.

My thoughts to it having only recently started, is probably something starting to fail.
Probably worth a run around the control cabinet, making sure all screw terminals are tight, and unplugging and reseating any pluggable connectors, just to make sure there's no corrosion in any of them.

Then I'd probably be looking at the spindle motor, and the controller.

[andy_con]

Not that original then.

What stepper drivers are fitted?
A photo of the control cabinet would probably be good.

My thoughts to it having only recently started, is probably something starting to fail.
Probably worth a run around the control cabinet, making sure all screw terminals are tight, and unplugging and reseating any pluggable connectors, just to make sure there's no corrosion in any of them.

Then I'd probably be looking at the spindle motor, and the controller.

well nearly original ;)

original stepper drivers.
cant get a photo till im back in workshop tomorrow now, its a bit messy inside be warned.

ill check all connections tomorrow

i did send the spindle motor away a number of years ago to be tested and reconditioned, set me back £500

[m_c]

That potential cost is why I swapped my spindle motor for a servo.

[andy_con]

not been in the cabinet for a while, its still messy :hopelessness:

https://imagizer.imageshack.com/img923/636/OModeh.jpg

https://imagizer.imageshack.com/img922/3121/UkjRxL.jpg

https://imagizer.imageshack.com/img922/9106/373cIz.jpg

https://imagizer.imageshack.com/img923/1083/avo7nh.jpg

https://imagizer.imageshack.com/img923/1910/dDHvjz.jpg

https://imagizer.imageshack.com/img923/1910/dDHvjz.jpg

https://imagizer.imageshack.com/img924/9560/mJvhjX.jpg

[andy_con]

video

https://youtu.be/stbWpra7O_4

so you can hear the z stepper moving the z axis

[andy_con]

All thoughts welcome

[Neale]

Any chance that it is a coupling or pulley slipping? Engraving - especially if you are V-engraving - tends to generate a lot of Z movement which might be aggravating something? I am assuming that nothing in the settings has changed.

[andy_con]

Any chance that it is a coupling or pulley slipping? Engraving - especially if you are V-engraving - tends to generate a lot of Z movement which might be aggravating something? I am assuming that nothing in the settings has changed.

no, it only happens when the spindle is on

[GND]

I wondered if you're getting issues from having the boards sitting on that pink bubblewrap. It's antistatic, hence may have some level of conductivity - maybe even enhanced by humidity - so it could feasibly be affecting the connections on the underside of the PCBs. Since you seem to be getting noise related issues, I'd suggest replacing that with something a bit more inert. In an ideal world you'd screw the PCBs down with spacers off a backboard of some kind, so nothing touches the backs of the PCBs. But for starters you could always try a bit of hardboard or MDF in place of the bubblewrap? Easy to try even if it's not the cause of the problem!

[andy_con]

I wondered if you're getting issues from having the boards sitting on that pink bubblewrap. It's antistatic, hence may have some level of conductivity - maybe even enhanced by humidity - so it could feasibly be affecting the connections on the underside of the PCBs. Since you seem to be getting noise related issues, I'd suggest replacing that with something a bit more inert. In an ideal world you'd screw the PCBs down with spacers off a backboard of some kind, so nothing touches the backs of the PCBs. But for starters you could always try a bit of hardboard or MDF in place of the bubblewrap? Easy to try even if it's not the cause of the problem!

now done this and its not made any difference

[andy_con]

heres an interesting development.

so when the z is at its height it would be machining at i get this z movement issue. if i lower the z right down to near the table, in a position it wouldn't be machining at i dont get the z issue.

so am now wondering if its some kind of cable issue. about a year ago i did have a cable break on the inside on the atc, the years of movements must have broken the cable.

[andy_con]

i appear to be finding more issues than solutions at the moment!!

just opened the black box at the back of the machine and noticed the below.

goo coming from the black hose connector block and then the electrical block below is wet. its gone all the way to the bottom connector.

https://imagizer.imageshack.com/img922/7356/VBMorX.jpg

https://imagizer.imageshack.com/img924/5818/KS9SvR.jpg

https://imagizer.imageshack.com/img924/2559/We0Dsp.jpg

https://imagizer.imageshack.com/img924/3600/f0Sabn.jpg

https://imagizer.imageshack.com/img924/5756/FhgQn6.jpg