Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Jackal on November 25, 2011, 12:37:42 PM

Title: question about limit travels
Post by: Jackal on November 25, 2011, 12:37:42 PM

I am setting up my limit switch travel limits.

Here is a pic  to help explain:

(http://img194.imageshack.us/img194/649/limitswitchsetup.jpg)

The machine is jogged into the home/limit switch, then backed off until the switch is cleared of error.

The digital readout is zeroed.

The machine is jogged in the opposite direction until the limit is tripped,  then backed off until the  switch is clear of error. <  ( It now reads 13.070 inches.)

I want  to set the machine: HOME= .100" off of the trigger, and soft limit .500 off of trigger.
    Opposite  soft limit is .500 from the other trigger.

How do I put this info in  the  following configuration  box:

(http://img265.imageshack.us/img265/8969/limitswitchconfig.jpg)


Would this work:

Home offset .100"

Slow Zone  1.00"

Soft min   .500"

Soft max 12.500"

I'll have to mess with the Home neg and reversed to see which direction I need, and the speed will be 10% for the slow zone.

Are there any recommendations for Auto Zero ?

I would like for the Z axis to home before the X & Y home out.

If this is confusing let me know.

Thanks in advance.

JAckal :)

Title: Re: question about limit travels
Post by: Hood on November 25, 2011, 01:57:20 PM

Standard is for Z to home first then X then Y but you can easily change that to suit by editing the order in the RefAll Button.
You do want AutoZero checked.

What I would do is set Soft Min as Zero and Soft Max as axis travel.
Dont enter a Home Offset unless you have seperate Home switches or home positive.

Ok so what happens when homing is your axis moves to the switch then backs off and then sets zero when the switch closes. That means setting a softmin of zero will be fine as it will not trigger the switch. There is a chance that it could hit the switch if your acceleration is less than it can act on in the slow zone distance you have set. So to set the slow zone what you want to do is home, jog away a distance then jog full rapid  towards the switch and see if the axis stops before it hits the switch, if it doesnt increase the slow zone, if it does then decrease the slow zone until it does hit a limit then increase slightly.
Hood

Oh BTW you will need to rehome each time after a limit has been hit during the slow zone setting up.

Title: Re: question about limit travels
Post by: ger21 on November 25, 2011, 02:01:39 PM

I think you want you're Home Offset to -.1. The Home offset is what the DRO is set to when homing.

Title: Re: question about limit travels
Post by: Jackal on November 25, 2011, 07:11:07 PM

Thanks guys,

That explained it better than anywhere I've looked.


JAckal :)

Title: Re: question about limit travels
Post by: Hood on November 26, 2011, 02:56:19 AM

Just noticed I said the homing sequence wrong, the default is Z first then Y then X , but as said you can do it any way you wish.
Hood

Title: Re: question about limit travels
Post by: Jackal on November 26, 2011, 10:04:06 AM

Thanks Hood,

As long as the Z is first, the rest will be ok with me. :)

I'm gonna leave the screens and these type settings  " stock" factory settings until I learn more about  Mach.

It will be easier for people to help me when I get in trouble.  ::)

Thanks again,

JAckal