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Author Topic: China 3020 Machine Losing Axis position  (Read 5564 times)

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Re: China 3020 Machine Losing Axis position
« Reply #10 on: October 30, 2012, 12:39:40 PM »
So after much screwing around..

I noticed today that with the spindle running the steppers move a bit at rest.

You can feel the steppers ticking, shut the spindle off the ticking stops.

So I am thinking that there is noise coming from the spindle that is stepping the motors.

Hmmmm??? Don't know how to fix that, I am sure it's part of the control box where the noise is coming from versus the spindle itself.

Mike in MN

Offline Hood

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Re: China 3020 Machine Losing Axis position
« Reply #11 on: October 30, 2012, 02:20:51 PM »
If it has a VFD controlling the spindle then that is the most likely cause. VFD's can be noisy and the cheaper Chinese ones tend to be the worst. Shielding cables may help, having a line filter to the VFD may help. Trying to route motor and power wires away from low voltage signal wires (step/Dir etc) may help.
Hood
Re: China 3020 Machine Losing Axis position
« Reply #12 on: October 30, 2012, 08:53:29 PM »
Thanks for the reply...

I rewired the spindle cable and one axis cable with shielded wire and grounded the shield, still no difference.

I did find something odd which might be part of the problem...

If I unplug the parallel cable from the control box the ticking stops in the stepper motors. But if I replug it in the ticking starts again, if I then leave it plugged into the control box but unplug it from the computer the ticking continues. I am thinking maybe I have a bad parallel cable that is picking up the noise some how.

Because either way, when I stop the spindle it stops, so it definitely coming from spindle noise, and yes there is a built in spindle control board in the control box that is variable.

I don't have a different parallel cable to test right now, but I will keep it up to date for those that may have issue in the future.

Did I mention I ordered a Gecko kit this week? I will overhaul the whole thing when I get the kit, but I have some things that I really need to get done with the unit now. Looks like I just might be behind a bit.

Mike in MN

Offline RICH

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Re: China 3020 Machine Losing Axis position
« Reply #13 on: October 31, 2012, 06:52:38 AM »
From your description seems the noise is picked up in the control box and the culprit is the spindle control board inside the control box. The spindle control is generating noise and that noise is coupled to everything else inside the control box.
Shielding the spindle control board and associated wire runs may help.
RICH
Re: China 3020 Machine Losing Axis position
« Reply #14 on: November 08, 2012, 12:14:50 AM »
So just to followup....

Spent far too much money in the last week but....

Bought the Gecko 540, Power Supply  and new servos and a water cooled 24k china spindle with VFD.

So after a week and my power supply being on the east coast I gutted the control box, left their power supply in there, wired in the Gecko, used the original servos (servos were in transit also) and had to design and mounting plate with a new designed spindle clamp. (Did I mention I own a cnc machine shop).

Mounted the spindle hooked it all together with a coolant pump and such and the darn thing actually runs good (after a re-calibration).

I am doing fine engraving on parts and I can rerun the engraver on the same part and there is no mismatch.

Oh, I rewired the whole thing with shielded cable and have it grounded.

When I get some time I will try to post pics of the modification.

The comment above was right, electrical sux on these machines, but the mechanics seem to be alright.

Mike in MN

Offline RICH

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Re: China 3020 Machine Losing Axis position
« Reply #15 on: November 08, 2012, 06:29:54 AM »
Happy all is working for you.
RICH