Messages

1

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 14, 2020, 01:07:56 AM »

that leave's with me only when I do Z10 Z0 code with error. must be a setting in MACH3 or a software issue.

or a bad z-axis controller

I do not think so as this controller give me an accurate Z5 Z10 Z0 motion.

2

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 13, 2020, 07:36:23 PM »

Add to the topic I have also tried swap the Z stepper on to X-axis and Y-axis controller and it gives me no error running the code.

so that gives me

no error in Z stepper

• it has tried with  Z5 Z10 Z0 code with no error
  it has tried with the x-axis andy-axis controller and with X10 X0 code give me no error

that leave's with me only when I do Z10 Z0 code with error. must be a setting in MACH3 or a software issue.

3

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 13, 2020, 07:24:32 PM »

I have set up as you suggested and I only run the Z10 Z0 code 20 times without moving the block as my problem is consistently creeping up. By using a feeler gauge the result had about 0.05 error so average out it had about 0.0025mm error each time it run.

with the same setup, Z5 Z10 Z0 code made almost no error as I do not have a feeler gauge small enough to fit the gap if there is any.

I think Graham may have solved the mystery so lets hope the cure is a simple fix.

Which motion controller are you using ?

What make and model is your stepper driver for the Z axis ?

Tweakie.

Hi

I can not find the options for low power standby or power-down option. can you please give me some direction on where that setting is?

I bought it from china-cncrouter dot com have no clue what is the motion controller and the stepper is just what came with the machine as well

thanks

4

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 08, 2020, 08:47:28 PM »

This may not be useful information but some time back we had a similar problem to this and it turned out to be this:-

The machine was setup with 10 microsteps and low power standby, when the axis stopped moving it instantly went into low power mode and the motor snapped to the nearest full step. on restarting the motor continued from the full step point, we killed the power down mode and everything went back to working properly.

power down mode? where can I find that option?

thanks

5

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 08, 2020, 05:46:20 PM »

Perhaps one more test you could do is zero your Z axis to a gauge block (any solid block would do) – carefully slide out the block – run your test 100 times – slide in the block – measure the gap with feeler.

This would verify the integrity of your dial indicator.

Tweakie.

I have set up as you suggested and I only run the Z10 Z0 code 20 times without moving the block as my problem is consistently creeping up. By using a feeler gauge the result had about 0.05 error so average out it had about 0.0025mm error each time it run.

with the same setup, Z5 Z10 Z0 code made almost no error as I do not have a feeler gauge small enough to fit the gap if there is any.

6

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 08, 2020, 05:33:57 AM »

If you repeat your "problematic" sequence 100 times, what is the result?
How do you measure micrometer difference? I guess that the resolution as well as repeatability of your machine is much worse than 2um.

my machine have about 0.01 resolution.

I'm measuring using a dial indicator. I fixed a dial indicator to the bed with the indicator pin to the bottom of the spindle shell. marked that as Z0.

I can see a noticeable change every time I run Z10 Z0, which raise Z to 10 them back to 0.  it has a consistent change of the Z hight each time I run the code. It averages out about +0.002mm. I have set up the code to run 100 times it had about +0.19mm in Z hight.
With the same setup, the code Z5 Z10 Z0, which raise Z to 5 then raise to 10 them back to 0. it has no noticeable change of the Z hight regardless now many time I Run the code. I have run the code up to 200 times it had no change to the Z hight.
I have also run the code Z5 Z10 Z5 Z0 , which raise Z to 5 then raise to 10 them back to 5 then back to 0. it also has no noticeable change of the Z hight hight regardless now many time I Run the code.

Thanks

7

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 07, 2020, 04:32:23 PM »

the 0.002 is an averaged number. as I did repeated z5 z0 10 times it becomes 0.02. I have also done z5 z10 z0 10 times it has no error.

thanks

8

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 06, 2020, 05:01:16 PM »

Hi

My acceleration is 150mm's and velocity is 2800mm's

thanks

9

General Mach Discussion / Re: Z axis inconsistent movement

« on: September 04, 2020, 01:01:01 AM »

Try reducing your Z axis Acceleration and Velocity (in motor tuning) by 50% and apply the changes. Does the problem still occur ?

Tweakie.

Yes, have tried that. Even to 10% it still has that. The odd thing is if I do step up or step down it does not have any error. Z5 Z10 Z15 Z20 Z0 will give me no error. Z20 Z0 will give me a consistent error each time I run it.

10

General Mach Discussion / Z axis inconsistent movement

« on: September 03, 2020, 06:07:27 PM »

Z axis inconsistent movement

My Z axis is creeping upward during the program run.
I have run the following gcode with a repeatable error.

The original location of Z 0
Code Run
Z10
Z0
Will give me a Z offset of +0.002mm each time I run it. But Mach 3 display is Z0.

Original location of Z 0
Code Run
Z5
Z10
Z0
Will give me a Z0 each time I run it and Mach 3 display is also Z0.

Basically start at Z0 with Z10 Z0 will give me an error in Z but Z5 Z10 Z0 will be correct.

Does anybody know how to fix this?