Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: carllance on July 19, 2008, 07:49:17 PM

Title: Touchy Limit/Home switches. Back off farther on Reference?
Post by: carllance on July 19, 2008, 07:49:17 PM

Problem:  Home/Limit switch is sensitive on Z axis.  When I Reference it backs off the swith, but barely.  When the machine begins a rapid move, sometimes the limit switch will trigger again.

Is there any way to instruct Mach to back off of the limit/home switch a bit farther after homing?

Thanks!
Carl

Title: Re: Touchy Limit/Home switches. Back off farther on Reference?
Post by: Hood on July 19, 2008, 08:00:27 PM

Try setting the debounce a bit higher, start at 2000 and work down until you get the problem again then back up a bit.

 You can set a G28 position and alter the code in your RefAll button .
Hood

Title: Re: Touchy Limit/Home switches. Back off farther on Reference?
Post by: carllance on July 20, 2008, 10:28:04 PM

I have actually done the G28 change in the RefAll button for now.   Good Idea!

As to debounce setting, doesn't that also effect limit switches in operation as well?  What about all inputs?

Thanks!
Carl

Title: Re: Touchy Limit/Home switches. Back off farther on Reference?
Post by: Hood on July 21, 2008, 01:34:47 AM

Debounce will affect the limits etc, probably  not as much as you would think but its definitely better to have it as low as possible.
 A faster home move on the Z axis may also do what you need if it is indeed a very sensitive switch rather than a bouncy switch.
Hood

Title: Re: Touchy Limit/Home switches. Back off farther on Reference?
Post by: Greolt on July 21, 2008, 03:11:54 AM

Carl

I noticed you posted about this on the SmoothStepper forum.

If you are using the SS it now has "digital filtering" or what Mach calls "debounce"

The good part about it in the SS is that it is a separate setting for homing, limits estop, probe etc.

So if yo set a substantial debounce interval for home switches it will not affect estop, limits etc.

Greg