Well, before I begin to use this thing in earnest I have taken onboard everyone’s advice and started fitting Limit Switches to the X, Y and Z planes. Everything is going smoothly, and as a matter of prolonging the usable life of the control electronics I have upgraded several components on the parallel port with high temperature low ESR electrolytic capacitors, half decent 5v and 15v regulators and a better spec TTL Tri-State Buffer I.C.
My question/query is that I only have input ports on Pins 10, 11, 12, 13 & 15 means that need to use the limit/homing method as in fig 4.7 of the manual in an OR configuration to where both ++Limit and the –Limit switch have the same signal i.e. active LO. This being the case how does Mach3 determine which way to work away from the active Limit?
I may not be putting this over too well, so to simplify: The Transverse Beam X is moving ++ towards the limit switch, it hits the limit switch and stops. How does it know which limit it has come against, and more to the point which way to move to allow it move off the limit…
Once (and if ever!) I finish the upgrades and modifications I will publish the details and offer the electronics at cost to anyone interested.
Recreational Chemistry is probably a more pleasing chore!