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Problem with referencing home and the limit switches
« on: February 24, 2007, 06:08:17 PM »
I just upgrade too version 2.0, so far so good but an old problem has remained and I need find a fix for it.

When I tell Mach to reference home, it does the Z and y perfectly everytime but when it does the X Axis it hits the home switch and then pops the E-Stop button. It's killing my production time because I can't zero out the gantry to use hard offsets for some of my jigs. I've been working around it by not letting the machine reference home at all when I'm doing a job.

The setup is have is a K2 3925 machine, I ordered extra switches from K2 so on the X and Y I have a limit switch on both ends. These are all wired in series and in the setup I have them set as X++, X-- and XHome. In diagnostics I can see all 3 light up when I reference X but the minute it touches the home position the EStop comes on (and the led's stay lit). What I find odd is that the Y Axis is setup identical, same wiring, same everything and it works just fine. What would cause Mach to trip the EStop when it's referencing the home switch? I can normally clear the EStop and then move the gantry off the home position just fine, in the last version when I attempted to move the gantry off that position it would re-trigger the EStop once or twice before I was clear of the switches.

Any help would be greatly appreciated.

Thanks
-Paul-

Paul Davis
Luthier
Patriot Guitars
Re: Problem with referencing home and the limit switches
« Reply #1 on: February 24, 2007, 06:16:06 PM »
Post your XML please :)
Fixing problems one post at a time ;)

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www.machsupport.com
Re: Problem with referencing home and the limit switches
« Reply #2 on: February 24, 2007, 06:21:42 PM »
Attached Brian... :)

I got this form a download here quite some time ago and have only made minimal changes to it.

Thanks
-Paul-

Paul Davis
Luthier
Patriot Guitars

Offline Chip

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Re: Problem with referencing home and the limit switches
« Reply #3 on: February 24, 2007, 08:55:47 PM »
Hi, ToadSprockett

Looked at your XML file, Changed the Ports/Pins X Inputs to Check mark's, If I remember right pin 11 is active High rev logic from pin 12.

Give this XML a try, jog out away from your table limit's ref Home, manually click the switches.

Hope this gets it, Chip
Re: Problem with referencing home and the limit switches
« Reply #4 on: February 24, 2007, 11:29:44 PM »
Sometimes the dragon wins   >:(

I tried your file Chip and monkeyed with the settings a little, once I got the motor's running in the right direction I tested switches, here is what I saw...

1. Moving the gantry to the center, I could trigger the X, Y or Z limits and the E-Stop would come on as expected. In Diagnostics the X and Y work identical and the Z shows the home and Z++ limits.

2. I then used the ref button on the Z,Y and X. The first two homed perfectly and the X will run to the switches and then trip the EStop leaving the LED's on. However unlike before I can clear the EStop and move the gantry out clearing the switches and everything is fine.

It's almost like there's a setting that's causing the X to trip the EStop before it can clear off of the toggles when referencing, the Y and Z both blip the LED's and the X sounds like it's going too but either it's not fast enough or I've missed a setting somewhere.

I changed the Config a little and have attached your Chip with my changes, so this is the latest version.

I'm at a loss as to why the Y would work and the X would not, I have the home speed set at %30 which is pretty tame, everything looks good to me. And the machine functions fine, all I need to do is get this fixed and I'm golden.

I've attached the latest XML file for perusal..

Thanks for your help.

-Paul-
-Paul-

Paul Davis
Luthier
Patriot Guitars

Offline Chip

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Re: Problem with referencing home and the limit switches
« Reply #5 on: February 25, 2007, 02:50:49 PM »
Hi, Paul

Sent you a Personal Message, its at the very top of this screen

Thanks, Chip

Offline Greolt

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Re: Problem with referencing home and the limit switches
« Reply #6 on: February 25, 2007, 05:08:17 PM »

I'm no expert but this sounds to me like it may very well be a noise issue.

Try upping your debounce time.
Re: Problem with referencing home and the limit switches
« Reply #7 on: February 25, 2007, 05:42:06 PM »
I talked with Chip this afternoon and with his help we figured out the issue, it's really very simple once you know where too look  ;D

Chip had some great suggestions about some of the settings and I'm working on cleaning up my settings now, but what was happening was that when the machine would reference home, the switch was a little sticky or 'bouncy' and even though Mach was pulling it off the switch to zero the axis it was not waiting long enough. Under General Config there is a Debounce Interval, it was defaulted to 100, we changed it to 2000 and everything works as expected now.

Also to reverse my motors I was using the Dir Low Active, Chip told me to change all my motors to be the same (which makes perfect sense of course) and to use the Home/Limits to reverse the motors. Once I clean up the file and re-test all my settings I'll post the XML here for anyone else using the K2-3925 machine.

Brian one thing I'd like to note is that I'm still seeing the behaviour where if I change the Dir Low Active the program changes the reverse in the Home/Limits, any chance of either stopping that or popping a dialog box asking permission before the program changes options in a totally different screen than the one the user is on? It can be very confusing and unless you know what to look for can cause all kinds of operator frustrations ;)

Cheers

-Paul-
-Paul-

Paul Davis
Luthier
Patriot Guitars
Re: Problem with referencing home and the limit switches
« Reply #8 on: February 26, 2007, 11:09:36 PM »
Paul,
If we get more people that get confused with this I think we may have to implement your idea.
Thanks and you are in good hands. Chip is very good

Brian
Fixing problems one post at a time ;)

www.newfangledsolutions.com
www.machsupport.com