[Chmfhm]

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.

Someone told me here in local market that go for servo motor with brakes and servo driver for z axis. Because when you do 3d carving zaxis carves .01mm to 0.001mm and stepper motors are not able to run fast to do this

What's your opinion

[CNCMAN172]

Chmfhm,
You will need a dial indicator to check backlash as well as steps per unit. You can pick up one pretty cheap at places like Harbor Freight. As Mactec54 suggested you should first check your steps/unit on the Z axis. If you can tell the Z axis to move exactly one inch does it move that far or is moving more or less. If you command a move of 1" it should move exactly 1"

Backlash is when you move one inch in one direction and command it to return to the starting point and it does not come all the way back. It is a little more involved but in layman terms this is checking for slop in the ballscrew / nut combination.

[CNCMAN172]

Someone told me here in local market that go for servo motor with brakes and servo driver for z axis. Because when you do 3d carving zaxis carves .01mm to 0.001mm and stepper motors are not able to run fast to do this

What's your opinion


3D carving a piece of wood does require many moves in all axis. However, the Z axis usually follows the controls of the object being cut, so think of a animal like a horse, so it will follow the contour of the horses body, moving up and down as it sweeps across the work piece. While servos might be able to respond faster, honestly many people do all kinds of 3D carving using stepper motors and they work fine. Focus on the issue with your machine, you can always upgrade to servo motors later after you have much more experience.

[Chmfhm]

Someone told me here in local market that go for servo motor with brakes and servo driver for z axis. Because when you do 3d carving zaxis carves .01mm to 0.001mm and stepper motors are not able to run fast to do this

What's your opinion


3D carving a piece of wood does require many moves in all axis. However, the Z axis usually follows the controls of the object being cut, so think of a animal like a horse, so it will follow the contour of the horses body, moving up and down as it sweeps across the work piece. While servos might be able to respond faster, honestly many people do all kinds of 3D carving using stepper motors and they work fine. Focus on the issue with your machine, you can always upgrade to servo motors later after you have much more experience.

I just check z axis move exactly 25mm up and down from start to finish. So steps of motor is correct.

Do I need to check backslash too ?

[CNCMAN172]

Check the steps/unit first, but they are related. If the steps/unit is wrong it can be adjusted, backlash is harder to fix and usually requires some new mechanical parts if you do not have a double ball nut.

[mactec54]

I just check z axis move exactly 25mm up and down from start to finish. So steps of motor is correct.

Do I need to check backslash too ?

If the movement went down 25mm and it moved back up 25mm then your backlash would be ok.

After you had cut the parts where the Z axis had moved down more than it should, when the program finished did it return to the Z axis 0.00 position where it started

[CNCMAN172]

The fact your steps per unit are correct and you have no backlash is good. Another test would be to run another experiment like you did before where Z axis just allows that board to fit. Now move just the X and Y all around the travel and when you finish moving the axis, stop and check the board again. Does the board still fit? It should but this tells us that the X and Y axis are isolated and not causing the issue on Z axis.

Mactec54 has a good question as well, this tells us if the axis reads 0.00 at the end of the program, then something else was causing it to move.

[ZASto]

Could be polarity of Step and Dir signals. If you have it wrong, that is what is happening.

[mactec54]

Could be polarity of Step and Dir signals. If you have it wrong, that is what is happening.

He has no problem with Step / Dir signals, motors are moving normally and positioning ok.

[ZASto]

@mactec54
If you have wrong polarity of Step/Dir signals you can and will miss steps, it bite me many years ago when I was greenhorn

[mactec54]

@mactec54
If you have wrong polarity of Step/Dir signals you can and will miss steps, it bite me many years ago when I was greenhorn

He is not missing Steps

As I said his axis is moving correctly.

[Chmfhm]

He is not missing Steps

As I said his axis is moving correctly.

At last my z axis works now flawlessly and smooth.

I borrow orignal leadshine dm542 stepper driver from my friend and replace it with cheap junk chinese dm556 stepper
driver and run machine more then 10 times without grounding and without sheilded wires. It works amazingly without any losing or gaining z axis. Next I will replace x y cheap chinese dm556 stepper driver with original leadshine dm542

And thx everyone for the help as I am newbie to cnc and you taught me.

[mactec54]

At last my z axis works now flawlessly and smooth.

I borrow orignal leadshine dm542 stepper driver from my friend and replace it with cheap junk chinese dm556 stepper
driver and run machine more then 10 times without grounding and without sheilded wires. It works amazingly without any losing or gaining z axis. Next I will replace x y cheap chinese dm556 stepper driver with original leadshine dm542

And thx everyone for the help as I am newbie to cnc and you taught me.

Normally the steppers don't need a shielded cable, only the VFD Drive to spindle

As I said it was an electrical problem, Leadshine make a good stepper drive so now you know what direction to go. you should replace all your drives, make sure you buy a genuine Leadshine drive as there are copies that look just the same, but don't work as well.

[Chmfhm]

Normally the steppers don't need a shielded cable, only the VFD Drive to spindle

As I said it was an electrical problem, Leadshine make a good stepper drive so now you know what direction to go. you should replace all your drives, make sure you buy a genuine Leadshine drive as there are copies that look just the same, but don't work as well.

During this I tweak with vfd. Now I have one last problem.

My vfd rpm doesn't match with mach3. I am sending you pics with vfd manual can you help me on this.

[mactec54]

During this I tweak with vfd. Now I have one last problem.

My vfd rpm doesn't match with mach3. I am sending you pics with vfd manual can you help me on this.

In Mach3 look at Ports/Pin Spindle setup tab PWM setting it should be 100

Check the Config Tab in Mach3 under spindle Pulley Ratio 0----24000-----1 you may have to adjust this to get the right output