Limits, homes, override switch

[cropwell]

Hi,

Now I am going to try and clear a little confusion (or add to it ?).

Homes - are basically positional references.
Limits (which are normally a little outside of homes) are the protection to stop you jamming the machine and/or damaging it. It is llike hitting E-stop in principle.

Mach3 when it does the homing, jogs the axis until it encounters the home switch and then moves back off the switch to a place where it is not triggered. Z axis is lifted to Home first, to raise the tool above the workpiece (usually). Then the Y and X, but the order is configurable.

So you need separate pins for Homes and Limits, as a triggered limit demands operator action to correct. You have to disable the triggered input manually first before you RESET Mach3 and then jog back to safety. You can then switch the Limit back into protection mode.

I use a buzzer to indicate that I haven't completed the process properly.

You can always use a 3PDT switch like this one below. BUT you don't need any reset for Homes if you keep them on separate input pins.

Cheers,
Rob


http://uk.farnell.com/multicomp/mcr13-432c1-01/switch-toggle-3pdt-on-on-sq/dp/2128057?ost=2128057&mckv=Pet0r2EX_dc|pcrid|7810829 0589|&selectedCategoryId=&CMP=KNC-GUK-FUK-GEN-SHOPPING-MULTICOMP&CAGPSPN=pla&gclid=CMad8Mvji8sCFQjlwgod3v IHHg&CAWELAID=120173390000201411&gross_price=true