Z endstop placement

Materials and drill bits all have different heights/lengths. Every time the machine homes, the furthest z point will be different. How the hell do you attach an endstop switch that will be versatile enough to account for different z heights? The leadscrew jams immediately when the router bit hits material or the bottom, so neither a stationary endstop nor one independently attatched to the leadscrew would work. The only thing I can think of is manually pushing a button just before it jams up. A little too makeshift it seems for a big machine. Any help? There must be a design out there. Maybe I could use z max instead of z min? Still gcode problems with that though.

Don’t hit the big home button. Just the smaller x and y home buttons. I use the z home, but have to have the touch plate leads, otherwise the thing will tear itself apart.

End stops are not common in cnc the way you are trying to use them. They are mostly for safety to make sure you don’t excede the machine’s build area. Or for production work.

If you insist on using them you will set them for every piece and use a touch plate for the z axis accounting for the offset.

As a reply to both of you, when I start repetier it marks all axis as unknown position. Until I home all 3 of them, I cannot manually control them. Also, every time I start a “print”, regardless of if it’s in the gcode or not, it attempts to home all 3 axis with the endstop switches, and if it has material or a bit, as you say, it tears itself apart. I’m just unsure how to get around this. Another gcode pumping program I guess?

Whatever program you are using must be inserting a G28 command as your start gcode. Just take it out of your program. If you have a look at my walkthroughs they show where it is.

Not sure about the unknown part. I understand what you are saying but I position mine by hand and just hit start. You can insert a different beginning gcode if you needed to but I have not had to.