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Author Topic: Ref Z axis & The Y axis moves Also!!  (Read 5702 times)

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Ref Z axis & The Y axis moves Also!!
« on: February 19, 2011, 11:15:17 PM »
Okay this is driving me crazy.  I do not have home switches on the X or Y axis, I only have a home switch on the Z axis.
But when I "ref all" the Z-axis Homes correctly but the Y axis moves .002".
This is the steps I have followed:
The mill is a Bridgeport Boss 5 converted to Mach3 Control, it has mechanical counters on the X and Y axis.
I jog the table to some position which I can read on the mechanical counters, say 6.000" Y axis and 9.000" X axis (this is the middle of the table), I then zero all the DRO's.  Then I switch to Mach Coordinates and click Ref All, the Z-axis moves as expected and zeroes but what is interesting is that the Y axis number changes and then zeroes the mach dro.  If I look at the mechanical counters the Y axis has moved .002" this is also verified by the Part DRO for the Y axis reads .002.  So it seems Mach is telling the Y to move even though it should not be.
If I hit ref all again only Z moves.
If I move the Y axis then ref all it moves .002" again.
Under Config Home/Limits X and Y are disabled.
If I go to the diagnostic page and click on Ref X it does not move as expected
If I click on Ref Y it moves the axis .002"
If I click on Ref Z it homes as expected and neither X or Y move.
So it seems for some reason Mach is commanding the Y axis to move even though it should not be.
Any help would be greatly appreciated.
John

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Re: Ref Z axis & The Y axis moves Also!!
« Reply #1 on: February 20, 2011, 03:09:10 AM »
Disable the Y axis in Mach and see if the axis still moves, if it does then its noise.
If you also attach your xml I will have a look and see if I can find a problem in the config.
Hood
Re: Ref Z axis & The Y axis moves Also!!
« Reply #2 on: February 20, 2011, 11:28:16 AM »
Thanks for the reply Hood,
Attached is my XML file.
I tried disabling the Y axis and this is what happens:
config ports pins - motor output
click check mark to disable
click apply
click ok
the reset button on screen flashes for a reset and the Y axis moves .002"
if I then re-enable the axis, apply, ok
the reset button on the screen flashes (just like the first time) but this time the axis does not move,
I jog the axis back to the same start point and do the same thing, disable, apply, ok
and the reset button flashes and the y axis has moved .002"
So leaving the Motor Output settings page causes the same type of motor movement problem as the Ref Y button.

So I think you may be right with the noise idea, I think the stepper motor is happier at certain positions and that if it is in between a little noise makes it jump to the next pole.

Now my question is why does Mach do anything at all if I click Ref Y if I do not have homing enabled on that axis?
Do you know what logic is followed when you ref an axis? If so maybe that would help me to determine where the noise is being interjected.
I really do not want to go thru all the wiring to figure this out since I am using all the original Bridgeport wiring from my BOB to the machine.
Additionally I noticed that if I am on the Diagnostics page and click ref X or ref Z they do not cause the Y axis to move, it is only if I click ref Y or ref all that the Y axis will move. So that has me a little confused as to where the noise is coming from, I would have thought the noise would be coming from the Z axis motor moving, (since it is the only thing moving when I do a ref all)  but that is not the case.  So what the heck does Mach do when you click REF Y if homing is not enabled on that axis that would cause noise in the circuit???

Is there some other way to "zero" the machine coordinates without using the ref button?
Since I do not use Homing on the x and Y I do not need to ref x and y but i would like to be able to zero them.
Because the Bridgeport has very accurate mechanical counters on the X and Y axis, what I like to do is jog the x and y to some position on the counters and then zero the machine coordinates.  this way I can check during tool changes if the steppers have lost any steps.

Thanks again for the help,
John


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Re: Ref Z axis & The Y axis moves Also!!
« Reply #3 on: February 20, 2011, 12:06:58 PM »
I would say if you have disabled the axis and it moves when disabled then you have confirmed noise is the issue and you should start looking at hardware.
Hood
Re: Ref Z axis & The Y axis moves Also!!
« Reply #4 on: February 20, 2011, 06:48:47 PM »
Is there any way to zero the machine coordinates without using the ref command?  At least this would get me by until I figure out the noise issue.
I am not sure were to start with the noise issue, since it makes no sense to me that mach should do anything if I have home disabled on X and Y it should just zero the DRO when ref is clicked, which would all be in software there should be no signals going to any hardware if there is no home switches on those axis.

Thanks,
John

Offline Hood

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Re: Ref Z axis & The Y axis moves Also!!
« Reply #5 on: February 20, 2011, 06:58:44 PM »
Mach does just that when you dont have home switches enabled, it just sets the axis zero for machine coords.

You could make a VB button up to do the same thing but really I suspect you are wasting your time but here is how its done.
SetMachZero(0) will set machine coords zero for X,
SetMachZero(1) is for Y etc etc.

Where your problem seems to be is you are picking up noise as the Z axis moves or when the stepper drives are enabled (pressing reset)
I dont know how you have things wired but stepper wires are best to be shielded, same with wires such as limits, e-stop etc when they are 5v.

Hood
« Last Edit: February 20, 2011, 07:01:34 PM by Hood »
Re: Ref Z axis & The Y axis moves Also!!
« Reply #6 on: February 20, 2011, 06:59:52 PM »
Perhaps you could disable ALL axis homing, jog to where you want 0,0,0 to be, then hit Ref All and see if anything moves.
Might be worth a try ?
Russ
Re: Ref Z axis & The Y axis moves Also!!
« Reply #7 on: February 20, 2011, 09:55:05 PM »
Hood Thanks again for replying.
I would agree that Mach SHOULD just set the axis to zero if home switches are disabled, but if this was true then there would be no signals going out/in to the parallel port and hence noise could not be the issue.  But if you assume noise is the problem then you would have to assume Mach is sending signals out of the parallel port for some reason.

Another reason I am having a hard time believing it is noise is because even if no axis are moving and while on the Diagnostics page I click on only REF Y the Y axis will move .002 I can see the DRO number actually change then set itself to Zero, also the LED's on the BOB flash for that axis.
I have now found out it will also do it if I click on only REF X the X axis will move .002".
Interestingly once it moves the .002 and you click ref again it does not move, but if I jog the axis and then re-click the ref button it moves .002 again.

Also if it was noise wouldn't it show up as lost or extra steps while running a program with all the axis moving, changing direction, stopping etc.? I have not seen it loose any steps while running a program. 

I tried making a VB button to set the machine coords to zero, as you suggested and unfortunately the same thing happens when I click the button the axis moves and the dro resets to zero.  Once again I do not understand why Mach would output any signals to the parallel port during this command?!?

I think you may have mis-understood my previous post, it does not happen when I Press reset, I was just saying that when you enable or disable a motor on the motor input screen when you ok out of this screen Mach goes into a reset condition, the axis moved while mach was exiting the motor input screen.

Russ,
I will try disabling ALL axis homing tomorrow I spent enough time on the machine today/tonight.

Thanks again for the help,
John
Re: Ref Z axis & The Y axis moves Also!!
« Reply #8 on: February 20, 2011, 10:52:52 PM »
Rest well John,
    Looking at your XML, it's acting quite strangely here.
Doesn't simulate very well, cannot emulate any of the home/limit inputs.
Increased the motor tuning speed but still will not jog properly at 100%.
The Step Pulse was set to "0" in Motor Tuning.
Your macro pump is running, wonder what is in it. ? ? ?
Any Brains ? Or Plugins configured ? Joystick/ShuttlePro  ? ?
I got this pop up when opening your profile, never saw that one before.
Good luck,
Russ

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Re: Ref Z axis & The Y axis moves Also!!
« Reply #9 on: February 21, 2011, 03:01:07 AM »
Russ
 I am not having the simulate problem here, I am getting the error message at the start but that is because the Joystick Plugin is enabled and no Joystick is attached.
Regards the Step Pulse, that is correct as Step Pulse of Zero in the XML signifies a kernel of 25KHz, 1 would be 35KHz etc

John
 I dont get any of the movement when I test your xml. If it is not noise then as Russ has said maybe its a Plugin, Brain or Macropump that is causing the issue.

Hood
« Last Edit: February 21, 2011, 03:03:06 AM by Hood »