I need help in solving issue I'm having in homing my milling machine.  I have Mach3 version R3.043.066, with MachStdMill version 2.3.6.

I have a ESS with CNC4PC C25 board.  I've hooked up an oscilloscope to look at the inputs, thinking it could be noise and after adding in debouncing and I've determined that there isn't any noise in the wiring.  I'm using shielded wire to each home switch and each home switch has its own input.  Shielding is only connected at the C25 card and not on the machine.

The problem. 
1) Hit Ref All in Mach3.
2) Z axis goes up towards z limit switch.  Not every time but most times it hits the switch and backs off like its supposed to.  But few instances it stops just short of the limit switch.  Mach3  then goes on to the y-axis.
3) y-axis just like the z-axis will start homing and not every time will it hit the y-axis home switch.  Get the same behavior.  If it does activate the switch, it stops then backs off.  But if the switch isn't activated it stops just short of switch, then starts to home X.
4) x-axis acts the same as the z and y axis. 

Funny thing is the behavior is the same for all three axis and its not as if the axis stops at some random location.  Its always just short of activating the limit switch.

I'm at my wits end on getting this figured out.  Any help would be appreciated.

Dave

If it's not electrical noise then I would suspect the limit switches (proximity / vibration / etc.)

Tweakie.

I can try to tap the machine with a dead blow hammer to see if its vibration.  But odd thing is the homing is stopping only right at or before the switch would click and there is no back off on the switch.  Would adding in a long debounce help to ensure very positive engagement of the switch.  Something else to try, really large debounce.

The switches are mechanical.  I've attached a photo of what I'm using. 

On the Warp9 ESS forum, I found a FAQ that the version of Mach3 I'm using had homing issues.  They recommend a different version of Mach3 3.043.062.

Can I install the 062 version over the top of my 066 version of Mach3?

Dave

PS. Just noticed I should have resized the attachments.  I will do better.

Do you have a limit switch and the home switch on the same input, if so disable all the limit switches and see if that helps.

Yes you can put .062 over .066 but try this first.

Each home switch is wired to an individual input on the ESS.  I do not have limit switches installed or configured in Mach3.

Think I've got it fixed. Not sure where the smoking gun is but here is what I did.

Made a backup copy of my c:\Mach3 folder.
Installed the 062 version of Mach3 from Warp9 website that had the windows 10 fix.
Tried homing. All three home switches clicked and on the hardware tap the lights for home switches lite up.  Thinking we have it. I home again.
This time the z indicator does not light and the axis stops, same issue as before.  The y-axis homes ok.  But x-axis does the same thing.

I know there isn't noise on the switches, but the comment on vibration, made me reinvestigate the debounce in the ESS General Config.  I've played with debounce before with no success.  But thought, why not try again.

For giggles I entered a value of 10.01 (7 increments of 1.43 microseconds) of debounce filter time.  Shutdown and rebooted.  Then restarted Mach3.

I'm happy to say that the machine homes every time.  I've homed it more than two dozen times from different starting points for each axis.  Success.

So many things changed, but eventually got there.

Thank you Graham & Tweakie for you questions.  It helped me get my issue resolved.

Dave