Limit switches

As noted previously, there are some rather nice Omron IP68 multiple limit switches fitted to the Shiz. 

There are dead stop trigger ramps at each end of the X and Y axes. The dead stop switches are normally closed (NC) and wired in series, so any one of them triggering opened the e-stop circuit and killed the servos in the old system. These are the Y axis ramps - the dead stop ramp is at the bottom, limit ramps at the top:

There are also limit switch trigger ramps at each end of the X and Y axes. The X trigger ramps share the same switch and the Y trigger ramps share another one on their axis. 

These are the ramps on the X axis (on the underside of the table) - the dead stop ramps are at the rear, limit ramps at the front:

It means that only 2 of the 4 available switches  are used in each switch assembly.

The Newkye controller wants to know which limit switch is at the +ve end (+L) and which at the -ve (-L), so I will need to reconfigure the physical and electrical arrangement of the switches.

The pins are 6mm diameter on 8mm centres. The trigger ramps are 10mm wide, so clearly I will need to reduce the width of the ramps if I want each ramp to only actuate one switch. I'll have to mill down the width of the active ramp on the Blidgeport but can leave the base of the ramp component at 10mm.

Finally, I will have to dedicate one wire for each of the limit switches on each axis (+L and -L) but the +L lines for the X and Y axes can be paralleled ie use the same wire, same with the -L. That's 3 lines plus 0V in total into the controller (+L, -L, dead stop and 0V). Doesn't sound so bad once figured out.