Chinese 6040 stepper drives

[Clive S]

i have just gone to set the job up and zeroed everything and noticed the stepper motor is creeping while on standby. i run the cutting program anyway just to see how it performed and when cutting in slow areas like arcs or corners the motor is noisy as if missing steps

I would check thee stepper motor connections at the bob to see if they are loose it could also be EMI does it move when the spindle is off. Which stepper is it all or just one?

[Jed Clampit]

it is only on the axis that the new board operates and it only seems to do it when the spindle is running

[Clive S]

it is only on the axis that the new board operates and it only seems to do it when the spindle is running

Then that sounds like EMI

[Jed Clampit]

what is EMI Clive ?

[john swift]

EMI is Electromagnetic interference

Is it just the new axis driver that's moving on its own ?

does your break out board look like this TX14175


John

[magicniner]

Then that sounds like EMI

Clive is spot on here.
The EMI often tracks up the mains lead from the spindle motor/driver and back down the lead to the PSU for the control system, separating the two to plug-in points opposite ends of the ring main can help, or running the spindle motor/driver from the furthest possible socket via an extension lead.
Ideally you'd fit separate EMI filters to the mains inputs close to the equipment.

[Jed Clampit]

thanks for the replies. i did a quick search and found these

https://www.cnc4you.co.uk/Electrical...FI-Suppression

[magicniner]

They should work, but if you have any particularly sensitive drivers they might still jitter a bit, I had some particularly sensitive drivers and ended up using filters and the long lead to a remote plug trick ;-)

[vondeliusc]

I am going to just throw in a blanket response here.
We have a 6040 CNCEST parallel (TX14175 BOB) and started to have Z problems intermittently.
At some point I discovered that the stepper wire on the gantry was janky; you could wiggle the wire
and the stepper would change tone. We cut out a section of the black 4-wire where it doubled back on
the drag chain, and spliced in a proper section and it fixed it. Then it started to do it again about a week later.
On closer inspection, I found on of the four wires from the motor itself where it went into the connector was
hanging by a thread because it had been over-crimped at the factory, so only one tiny filament was making contact
and that was actually separated and only mechanically touching the crimp of the pin.
We replaced the motor connector with a proper Molex 4-pin aviation connector and no problem.
Later it happened again, this time on the gantry axis, and when continuity testing with a multimeter, we found one of
the runs (on the gantry (Y)) had one wire broken inside 'somewhere'.
That was the last straw, so we replaces ALL the wire runs from the controller with PROPER aviation 4-C shielded wire
from the controller to each motor AND replaced ALL the remaining motor connectors to get rid of the HORRIBLE Chinese wire.
There was more to the troubleshooting nightmare, including swapping stepper drivers, AND purchasing a used TX14207 stepper driver
off eBay because we 'thought' the stepper driver was the fault (it was not).
So sharing this lesson before you tear all your hair out in futility.
-Christian