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Trouble with limit/home config
« on: May 09, 2013, 01:47:03 AM »
My newly commissioned router is working pretty well.  The setup is PMDX-132 breakout board, Gecko 203V drivers, SmoothStepper/USB, and PMDX-107 spindle control.  I finally got around to adding limit switches and am having trouble configuring things.  I have a separate input (I know I don't need to) for X+, X-, Y+, Y- , A+, A-, and Z+ and have enabled both the limit and the home functions on X-, Y-, and Z+ and the limit for X+ and Y+.  The Hall effect limit switches all work fine.  The trouble is that when I hit the "Reference All" button, the machine references the Y axis, triggers the limit, backs off a bit, with the limit alarm still active requiring a Reset to clear.  End of referencing!  I cannot figure out how to get Mach to continue and reference the other axis.

I'm betting this is a simple issue, but so far I haven't tripped across the answer!

Help would be appreciated!

Offline Hood

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Re: Trouble with limit/home config
« Reply #1 on: May 09, 2013, 03:11:23 AM »
Sounds like your switches are "bouncing", try setting some debounce interval on General config page, try 2000 and if it helps work down until it returns then bump up slightly.
Hood
Re: Trouble with limit/home config
« Reply #2 on: May 09, 2013, 01:21:24 PM »
Hard to understand how hall effect switches "bounce".  I am pretty sure they have a hysteresis built in.  But in any event, changing it to 2000 had no effect.  But I have solved part of the mystery.  With two switches and "Home Slaved to Master Axis" checked, on side would remain within the limit switch proximity after the other side backed off.  Unchecked, it works as advertised, although one side backs off further than the other, with exactly the same offset from the gantry to the switch on each side at the start, such that the gantry winds up being racked by about .25" after the Reference All.

In addition, although it (poorly) references the Y axis (gantry), there is no attempt to reference the X and Z axis.  What's with that??

Offline Hood

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Re: Trouble with limit/home config
« Reply #3 on: May 09, 2013, 02:17:28 PM »
Quote
Hard to understand how hall effect switches "bounce". 

I had that in inverted commas for a reason ;)
I was thinking more along the lines of machine vibration triggering your switches.
Anyway if you attach your xml I will have a look.
Hood
Re: Trouble with limit/home config
« Reply #4 on: May 09, 2013, 06:01:21 PM »
Here you go...

Offline Hood

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Re: Trouble with limit/home config
« Reply #5 on: May 09, 2013, 06:05:11 PM »
You do not have X or Z home switches set up in Mach so it will not move those axis when you reference. See screenshot.
Hood
Re: Trouble with limit/home config
« Reply #6 on: May 09, 2013, 09:48:42 PM »
Hood:

You might want to try that again.  The screen shot that you sent doesn't reflect the file I uploaded.  (Although I did note that the Z home is not checked!)  I just downloaded my own upload and it clearly shows X-- and X home enabled.

Joe

Offline Hood

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Re: Trouble with limit/home config
« Reply #7 on: May 10, 2013, 03:14:06 AM »
My apologies, I opened another profile here with a very similar name to the one you uploaded. Yes yours does not have the Z home enabled so that will not home.
 So if you have enabled that do the three axis home correctly now?
If not can you try homing the X alone from the diagnostics page and tell me if it works.

I also see you are using a SmoothStepper, my suggestion of debounce would not work as it has no effect when using an external device. To use the equivalent of Debounce Interval with the SmoothStepper you set a filtering value in the SS Config.
Hood
« Last Edit: May 10, 2013, 03:16:40 AM by Hood »
Re: Trouble with limit/home config
« Reply #8 on: May 10, 2013, 01:29:44 PM »
I changed the Z Home.  All three axis reference okay from the Diagnostic page, although the Y and A motors back off different amounts for some reason, racking the gantry.  I changed sensors there to no avail.  But the main problem is that only the Y axis references when you hit th Reference All button.  I opened the Reference All button with Edit Button Script and get,

DoButton( 24 )
DoButton( 23 )
DoButton( 22 )
DoButton( 25 )

DoOEMButton(133)
DoOEMButton(134)
DoOEMButton(135)

Not sure which DoButton does what, nor how to look at the DoButton() code!

Offline Hood

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Re: Trouble with limit/home config
« Reply #9 on: May 10, 2013, 01:32:36 PM »
Ok, are you using the latest lockdown or Dev version? There are known issues with homing with these versions and this may be one of them.
Hood