right now i have a c35s bob
uunless im doing it wrong ..im out of inputs
estop 10
probe 11
x y and z limits 12..13..15

i want to hook up an index signal for tapping... and also want to add a 5th axis down the road...
can you guys recommend a BOB that will allow me to do this ..

or can i add an expansion board ....
your input is appreciated as always

rick