Topics

1

Mach4 General Discussion / dangerous malfunction of a machine driven by Mach4

« on: February 20, 2022, 11:24:33 AM »

Hi guys,

I faced with a very dangerous error yesterday while running a gcode in Mach4, in short the problem is; Mach4 looses its zero point while running gcodes, this happens once in a while, like 1 out of 8 jobs. At first it was like missing the zero point in X(generally X, couple times it happened in the Y too) within 40-50mm, i was stopping the code and realign the axis and go on from there, but yesterday it lost the zero point by 400mm!! i was not close to the machine so it went 400mm(approx.) back in -X direction and hit the limit switch so that the machine stopped. (There is a malfunction in the front, +X direction limit switch, i ordered the new one and waiting for it to arrive to change it, so if it moved in the + direction it would not stop by hitting the limit switch and that would kill the machine for sure, this is a c3 ballscrews attached 4 ton machine, so it would cost very much). First thing tomorrow i will attach a small limit switch i have in hand to the +X direction before running the machine again.

But this problem is very weird, most of the code runs normally, i always generate the gcode from Solidworks, HSMworks with Mach3 post processor, so there is nothing wrong with the code(i am posting the code anyway), in general there is no noticeable noise in the machine and if it was noise i think i should get the same error in every gcode i run but this happens once in a while and can not say when actually. Gcode runs normally but suddenly at some point zero point of X moves back to 400mm and machine thinks that it is in the wrong place and moves back to keep up with the coordinate in the code, so it moves in a wrong place. It ruins the part, in addition to that a high quality PCD bit and sdc holder was installed yesterday and just because of the luck it didnt hit to anything while moving to the wrong coordinate. the plate is relatively big so in general i attach other jigs on the plate i was lucky it didnt hit them.

So as you can understand this is a very very serious malfunction for a cnc machine in every aspect.

I searched the web and forums for a similar error and found out that Mach3 users faced with the exact same error before but no one understood why this happened or didnt post any solution about it.

X axis is driven by a 16NM stepper motor, 100 microstep / 30.000 pulse per revolution, (i have a 11NM servo and using the stepper because its more powerful, the Y+Z axis is 600kg in weight approx.) its driving a 40mm diameter, C3, zero backlash, 5mm pitch ballscrew, i also attached the speed, accel. values for you guys to check. My positioning accuracy is within 5microns.

I was using my own screen while this first started, thought that it may happen because of the screen and reinstall Mach4 and ESS plugins with latest stable versions and started to use Mach4 standard screen as is with no modifying on it. The PC motherboard and ram capacity is more than enough for running Mach4, nothing wrong in device manager and all drivers are up to date including the gpu.

Do you guys have any ideas about the reason and solution of this weird problem? anyone faced with the same error while running a gcode? why would Mach4 loose its zero point by 400mm during operation? any ideas are really appreciated, thanks in advance.

Hakan

2

Mach4 General Discussion / surface map

« on: April 15, 2021, 11:07:41 AM »

Hi,

There are couple things that i dont understand in surface mapping, if anyone can help me understand i will be glad;

I am trying to make surface mapping work for PCB engraving, i can map the surface and when map is loaded i can see the automatic adjustment in Zth axis within the mapped area during jogging and gcode running.

Machine homes in place and for the test, 150mm x 150mm area mapped, with 5mm resolution in both axis, zth axis adjustment precision during jogging was within 4 microns. Machined PCB was 100mm x 100mm and gcode prepared in HSMWorks.

First problem; after loading the map and when i close the plugin window, the zth axis jumps up suddenly, this move is so strong it shakes the 4 Ton machine,

second problem; when axises move outside of the mapped area zth axis again jumps up suddenly, it does not ramp up as it does in the youtube video,

third and the most important problem;

i can not zero the zth axis correctly, when i use the same tool(or when changed the tools) to zero it on the PCB from the touch off UI, it displays 10.77 in the Zth axis DRO instead of 10, i dont know where this 0.77mm is coming from. You can see the values i enter to the touch off UI in the attached image, when the touch plate is the actual plate(which is PCB) the plate height should be entered 0 and the retract height is 10mm after probing so, DRO should display 10mm after probing right?

What am i missing in here? does surface map plugin adds the measured value during mapping at that coordinate to the probing result? If so, its not good. Because of this i can not carve the PCB correctly, the value it should dive in to the PCB is -0.04mm but it enters way more than that and cleans up all the paths. I cannot fix it by altering the 0 point from the DRO, i cannot find the exact error and not sure if it is 0.77mm.

I am sure there are things that i dont understand about the concept of surface mapping, if anyone can help to correct those problems i will be glad, thanks in advance.

Regards,

Hakan



 

3

Mach4 General Discussion / Map surface wizard does not function

« on: March 16, 2021, 01:41:26 PM »

Hi all,

I am trying to engrave some PCBs and having difficulties with Map Surface wizard, when map surface button clicked X and Y axis moves to the machine coordinate 0 point but Zth axis does not make any move, wizard stops there, therefore it can not probe the surface of the PCB. Please check the attached video.

Anyone having difficulties with Map Surface wizard? or anyone using it with success?

I contacted with support team they said it is working without any problem and advised me to make new profile from scratch, i did it, also used the default screen set but the problem is same, it still does not function and act the same way.

Last version of ESS and Mach4(4.2.0.4680) is installed but reverting back to 4.2.0.4612 because 4680 has some problems with the screen, there is some latency with the clicks on screen and machine movement in manual override.

But this Map Surface wizard problem is there in every Mach4 version for me, any suggestions?

Regards,

Hakan

4

Mach4 General Discussion / Mach4 positioning error

« on: December 12, 2019, 12:40:09 PM »

Hi all,

there is a problem which made me take apart the new built machine, there is a positioning error in every axis, here is the machine details;

Windows 10 32bit, Mach4, ESS, PMDX 126 as controller,

X Axis:

1300mm stroke, 25mm diameter with 25mm pitch Taiwan made single nut ballscrew directly attached to a servo motor with coupling(this motor replaced with 16Nm step motor to rule out the motor/driver combo error, it gave same results with servo system),
Ballscrew aligned with the guideways within 0.01mm from one end to another both vertically and horizontally,
there is a measured 10-15micron backlash.

Y Axis:

1000mm stroke, 25mm diameter, 5mm pitch Taiwan made double nut ballscrew directly attached to a closed loop step motor with coupling,
Ballscrew aligned with the guideways within 0.01mm from one end to another both vertically and horizontally,
there is a measured 4-5micron backlash.

Z Axis:

1000mm stroke, 25mm diameter, 5mm pitch Taiwan made double nut ballscrew directly attached to a servo motor with coupling,
Ballscrew aligned with the guideways within 0.01mm from one end to another both vertically and horizontally,
there is a measured 4-5micron backlash.

All the guideway(30mm schneeberger) beds scraped and aligned/paralleled within 15microns in both vertical and horizontal plane.

This is a very rigid machine which weighs 4tons, it is precisely leveled, motors has no problem while driving, no noise, no heat, there is no other error in the setup other than this positioning error.

At first i thought maybe servos doing it but Y axis has a closed loop step motor and a double nut ballscrew aligned within 10microns, which makes the exact same error with X and Zth axis.

I am confused with it, tomorrow i am going to reinstall Mach4 and ESS plugin from scratch and make the test with the standard screen which comes with Mach4 but other than that nothing comes to my mind.

It also does not cut the circles true, in 30mm diameter it makes +60micron error.

below images are the measurements in one way(to rule out the backlash), first command is 1mm forward, next is 2mm forward etc.. it always comes short, there is no errors in ballscrews or motors and their tuning, thats for sure, i am focusing on Mach4 and ESS right now, anyone has any idea about the possible cause of this positioning error? or anyone faced with a similar problem?

Regards,

Hakan

5

General Mach Discussion / Linear axis error compensation

« on: September 07, 2019, 08:41:55 AM »

Hi all,

I am sure i am not the first one who get to this idea about fixing the error of a linear axis but i couldnt find the topic related with it in the forums and couldnt find what u guys call it so i posted it in here, if u have a knowledge related with the matter please direct me to the related post, thanks.

The idea is simple;

If there is a fixed and measured error of a linear axis(lets say, up and down error for the X axis), u should be able to compensate it with the Zth axis(by moving the Zth axis up and down in predefined positions of the X axis).

U can understand what i mean in the attached image better, in this image there is a graph which illustrates the up and down error of the X axis and the movement required to fix that error by the Zth axis. This is an interface illustration for this compensation so that user can enter the measured error in means of distance according to the machine coordinates and the error measured by the straight edge-micrometer or laser interferometer. For example, X axis length is 1300mm and the total error is 60 microns.

We are assuming that the error is fixed and repeating in every X axis movement, body of the machine is rigid and we have ability to move the axises to exact positions, they can be precisely controlled.

This error fixing can be adapted to gcode or by manually to MDI but better then that if u can find a way to adapt it directly to the controller(Mach4) there wont be any user activity needed to fix it in each time, machine will automatically move the Zth axis incrementally according to the reached predefined machine coordinate and the error will be compensated automatically.

The main idea in here is to fix the physical error of the machine bed by means of programming the controller to avoid that error without the need of disassembling the machine and fixing the error physically.

So i am looking for help to adapt this directly to Mach4, is there a way to do this by scripting? or a plugin is necessary?

Thanks in advance.

6

Mach4 General Discussion / Mach4 Spindle At Speed, Spindle Zero Problem

« on: September 29, 2017, 06:24:53 PM »

Hi,

When all necessary adjustments made Mach4 does not wait spindle to come at speed entered in gcode or MDI before starting machining.

Delta brand VFD is adjusted to send signals of Spindle at speed and spindle at zero to 2 inputs and they can be seen in diagnostics page and they function ok, in spindle tab wait for spindle to stabilize is selected, but when i hit cycle start machine dive into gcode whlie spindle is still accelerating.

This is clearly a bug in Mach4, is there a solution for this?

Regards,

Hakan

7

Mach4 General Discussion / Problem with ESS Mach4 Spurious Limit hit event

« on: August 21, 2017, 03:53:49 PM »

Hi,

I am facing some problems with Mach4 and ESS,

1st- both Mach4 and ESS are last versions, when i try to open ESS Diagnostics window, it pops up and when i move the mouse it locks Mach4 and give some error related with wxwidget..... (u can see the error below) and force Mach4 to shut down,

2nd- when i select home switches as -limits, in -limit hits Mach4 gives "Spurious Limit Hit Event...." error and locks the interface, other than this home switches works fine machine homes itself using home switches just it does not zero the axis DROs, i had to disable the -limits to be able to operate Mach4, also if i assigned +limits as -limits for test, it does not give that error so i am guessing this problem is not because of noise, ( Andy from ESS could not help me about this problem)

3rd- spindle works fine, it turns as commanded, vfd is Delta brand and it provides Spindle at speed and zero speed signals which i mapped to port1 Pin11 and Pin12 and when spindle reaches the entered frequency by gcode "spindle at speed" led lights up in diagnostics and when it stops "zero speed" led(i put it myself) lights up in diagnostics so vfd sends the signals correctly but when operating a gcode in MDI machine does not wait the spindle to come up to speed. So i guess a M3 macro should be written to implement this feature to Mach4. Can u help me in writing this macro to tell to Mach4 in M3 command it should first wait Pin11 to be activated and make sure the pin12 is not active for going on to the rest of the gcode.

Thanks.