Endstops (1 or 2 per axis)

Hi!

Unfortunately my computer for my Linux is not ready yet, so I'm not able to try it out and thought, maybe you could help me, since I want to continue to build my CNC.

I want to use a cheap ebay 3 axis controller for my first steps. I found tutorials on how to connect them to LinuxCNC. The controller has 4 digital inputs for endstops and emergency stops. So I'm going to use endstops in the home-position either way. But I have some switches left, so I thought I could connect two switches per input (an endstop on the other side) so you get a stop signal if you reach the home-end or the other end.

So my question: Is LinuxCNC able to interpret which end of the table it has reached? Or will this lead to problems?

Of course, the machine should never reach the "other" end, since this would mean I made a programming mistake. But for safety those switches would come in handy.

Thanks!

yes it can , the sequence is home switch and then once homed it becomes a limit

PCI parallel ports are really inexpensive, so I don't worry about saving inputs. I prefer the full set of +, - and home sensors (Hall preferred for coolant protection) for each axis. The home sensor is used with the axis encoder index. This makes it convenient to home in the middle or another place on an axis. Separate limit sensors let LinuxCNC know which end has tripped and to react appropriately, although if you are homed properly, one should not hit a firm or hard limit.
--
Kirk
wallacecompany.com/machine_shop/index.html