[Chmfhm]

First you have to have a Ground Plane, where everything is mounted too in your Box is the Ground plane, check the incoming main power supply Ground is mounted metal to metal this then Ground the Box this is important to have a Good Ground anything then that is in the box can be Grounded to a Ground Bus or stud this has to be done correctly or it will be ineffective I will post some snips of how the shields have to be Grounded

You must remove all paint or anodizing and have bare metal for all Grounding connections

P-Clips are best for Shielded Cable, a saddle clamp will work, both types must clamp the shield tight

Post some photos of inside your Box / Cabinet I can see better what you have to do.

Thanx for your help. Once i done with thesei will reply you back. Hope this solve my problem

[Chmfhm]

Thanx for your help. Once i done with thesei will reply you back. Hope this solve my problem

I shielded all axis wires and ground the shielded wire.

After that i run machine but the issue of z axis was still as it is.

After that i replace the BOB and remove spindle cables x axis cable and the y axis cable from the BOB. And also from electricity. Just Run only the z axis. But the problem with the z axis is still the same. I also changed the z axis motor. The new motor has 2.8 torque. But the problem is that it is not going to be solved of z axis.

Also i added emi noise filter on my 220v too

Sometimes i thought why i am into cnc thing

[CNCMAN172]

Does this machine use a USB interface versus a parallel interface card? If this is a USB interface, my bet is you are getting EMI interference causing the z axis to move just slightly as you try to move. You might be able to resolve this by purchasing a USB isolator, which is cheap about $15 and it isolates the laptop from the machine, so no EMI can cause Mach3 to do strange things.

Russ

[Chmfhm]

Does this machine use a USB interface versus a parallel interface card? If this is a USB interface, my bet is you are getting EMI interference causing the z axis to move just slightly as you try to move. You might be able to resolve this by purchasing a USB isolator, which is cheap about $15 and it isolates the laptop from the machine, so no EMI can cause Mach3 to do strange things.

Russ

Yes it is usb interface and usb cable is sheilded and has emi/rfi attached 6 inches from computer end connector

[mactec54]

Yes it is usb interface and usb cable is sheilded and has emi/rfi attached 6 inches from computer end connector

Can you post some close up photos, of the wiring, I may see something that is causing the problem.

[CNCMAN172]

Chmfhm,
The fact you have a shielded USB cable with ferrite beads at both ends is great but this does not isolate the PC from the CNC electrically. I had the same crazy issues going on with my USB KFLOP board it worked but would do strange little moves and suddenly lose contact and re-establish it was making me tear my hair out. Someone on Cnczone metioned USB isolators and I was out of options so I ordered one which was under $15 and plugged this little board right before the PC and the USB cable plugged into the isolator. Just like magic my issues disappeared. I still use it today. This is an example of what they look like there are many makers of these units.

https://www.ebay.com/itm/18301419381...QAAOSwDEBcRWGU

[mactec54]

Chmfhm,
The fact you have a shielded USB cable with ferrite beads at both ends is great but this does not isolate the PC from the CNC electrically. I had the same crazy issues going on with my USB KFLOP board it worked but would do strange little moves and suddenly lose contact and re-establish it was making me tear my hair out. Someone on Cnczone metioned USB isolators and I was out of options so I ordered one which was under $15 and plugged this little board right before the PC and the USB cable plugged into the isolator. Just like magic my issues disappeared. I still use it today. This is an example of what they look like there are many makers of these units.

https://www.ebay.com/itm/18301419381...QAAOSwDEBcRWGU

He does not have a USB issue, or the other axis would have problems as well, there is nothing wrong with adding what you suggest, I would be very surprised if it solved his problem

[CNCMAN172]

Mactec54,
It is true noise could impact other axis as you suggest. On my machine I had strange stuff happening only on Z axis as the spindle moved around those cables got closer to EMI sources. This also could be the weight of spindle causing motor to slip due to weight it is being asked to support. A counterbalance shock might address the issue. A good test would be remove spindle and check and see if it keeps dropping

[mactec54]

Mactec54,
It is true noise could impact other axis as you suggest. On my machine I had strange stuff happening only on Z axis as the spindle moved around those cables got closer to EMI sources. This also could be the weight of spindle causing motor to slip due to weight it is being asked to support. A counterbalance shock might address the issue. A good test would be remove spindle and check and see if it keeps dropping

If there is EMI from the spindle, it's from incorrect wiring, he still had the problem without the spindle and other axes connected

I think he did remove the spindle.

If you watch the video, it moves all by itself after the machine has stopped, it's getting a signal to move from the control, this could be bad Optos as well, although he tried another Board and it still happened, it could be the stepper Drive also

[mactec54]

I shielded all axis wires and ground the shielded wire.

After that i run machine but the issue of z axis was still as it is.

After that i replace the BOB and remove spindle cables x axis cable and the y axis cable from the BOB. And also from electricity. Just Run only the z axis. But the problem with the z axis is still the same. I also changed the z axis motor. The new motor has 2.8 torque. But the problem is that it is not going to be solved of z axis.

Also i added emi noise filter on my 220v too

Sometimes i thought why i am into cnc thing

The stepper motor may be too small for the job what are others using on the same machine as you have

How did you Ground the Shield, there is a right way and a wrong way??

[Chmfhm]

The stepper motor may be too small for the job what are others using on the same machine as you have

How did you Ground the Shield, there is a right way and a wrong way??

I connect sheild with wite at motor end and that wire directly connects to ground cable.

As i told you i remove all axis wire and also remove spindle wires from Bob and from power supply. Just z axis wire connected to bob and powr supply.

First 57hs76 2804 motor is installed on z axis which has holding torque of 1.8nm now i install 57hs100 2804 motor which has holding torque 3nm.

[Chmfhm]

The stepper motor may be too small for the job what are others using on the same machine as you have

How did you Ground the Shield, there is a right way and a wrong way??

I order usb isolator from china it will take 15 to 20 days. Meanwhile I will remove spindle from frame today and run z axis to check my problem and let you know

[mactec54]

I connect sheild with wite at motor end and that wire directly connects to ground cable.

As i told you i remove all axis wire and also remove spindle wires from Bob and from power supply. Just z axis wire connected to bob and powr supply.

First 57hs76 2804 motor is installed on z axis which has holding torque of 1.8nm now i install 57hs100 2804 motor which has holding torque 3nm.

The Shield connection is incorrect, it must be clamped at both ends as in the photos I posted, you can't use the drain wire connected to Ground, using the drain wire is ineffective and can cause even more problems that what you already have. look at the photos again this is the correct way to clamp the Shield.

[Chmfhm]

The Shield connection is incorrect, it must be clamped at both ends as in the photos I posted, you can't use the drain wire connected to Ground, using the drain wire is ineffective and can cause even more problems that what you already have. look at the photos again this is the correct way to clamp the Shield.

I just removed the spindle from the frame. Then place a piece of mdf under the spindle holder and zero the z axis in mach3. Then i check the mdf piece by moving it back and forth under the spindle holder. Then irun the G code. After 5 minutes I stop G code to check again. I try to place same mdf piece under spindle holder but was not able to insert under spindle holder.

I sending you link of video you can check in start of video it is movable under spindle holder. And in last of video you can see clearly that I am unable to put back again mdf peice under the spindle holder.

https://drive.google.com/file/d/13YhOtTQylaEcSZHMkzS3089ZMaXFtdRl/view?usp=drivesdk

Also I swap x stepper drive with z to check whether it's a problem of stepper driver or not. But problem remain same

[mactec54]

I just removed the spindle from the frame. Then place a piece of mdf under the spindle holder and zero the z axis in mach3. Then i check the mdf piece by moving it back and forth under the spindle holder. Then irun the G code. After 5 minutes I stop G code to check again. I try to place same mdf piece under spindle holder but was not able to insert under spindle holder.

I sending you link of video you can check in start of video it is movable under spindle holder. And in last of video you can see clearly that I am unable to put back again mdf peice under the spindle holder.

https://drive.google.com/file/d/13Yh...w?usp=drivesdk

Also I swap x stepper drive with z to check whether it's a problem of stepper driver or not. But problem remain same

What was the DRO in Mach3 reading when you started and when you finished was it at 0.00 start and finish

[Chmfhm]

What was the DRO in Mach3 reading when you started and when you finished was it at 0.00 start and finish

Yes it is 0.0 on start and 0.0 on stop or finish

[CNCMAN172]

Very strange issue. Since you did not have the spindle running, I am going to venture a guess this is not EMI interference, however it can still happen from other sources. I am leaning towards some kind of mechanical issue, can you check your bearings on the Z axis and see if anything in loose. You also need to check backlash on the Z axis to see if that is playing a role. Did this machine every work correctly?

[mactec54]

Very strange issue. Since you did not have the spindle running, I am going to venture a guess this is not EMI interference, however it can still happen from other sources. I am leaning towards some kind of mechanical issue, can you check your bearings on the Z axis and see if anything in loose. You also need to check backlash on the Z axis to see if that is playing a role. Did this machine every work correctly?

The video shows the motor turning after it is stopped so it is being driven by the drive, it's getting power from some where to do this.

[mactec54]

Yes it is 0.0 on start and 0.0 on stop or finish

So has the axis been calibrated correctly Steps/ Per could be off which could cause this??

In MDI do this Z-1.00F20. and check to see if it has moved 1" or if you are using mm then use 25mm

[Chmfhm]

Very strange issue. Since you did not have the spindle running, I am going to venture a guess this is not EMI interference, however it can still happen from other sources. I am leaning towards some kind of mechanical issue, can you check your bearings on the Z axis and see if anything in loose. You also need to check backlash on the Z axis to see if that is playing a role. Did this machine every work correctly?

It's a new machine. Just open box last month. It is doing since day first. I will check bearing today. Also can you guide me how to check back slash on z axis