I’m about to do an adapter for the @Printrbot Simple (Late 2014 model) for a Z-Probe. I know where to get the firmware and understand the concept.
But how does the probe switch connect to the printrboard? Does it replace the Z limit switch or connects in parallel?
If in parallel how do I set the Z limit switch trigger? Which trigger first the Z-Probe of the Z limit switch ?
Even though I don’t have a printrboard, I think I can help out a bit here. On my printer, I have both the Z probe (attached near the hot end on a servo) and the Z limit (fixed position) in parallel. My switches are wired in the Normally Open configuration. You need to make sure they are Normally Open to wire in parallel. Wire them in series if they are Normally Closed.
With the auto-level feature, you don’t need both the z limit and the z-probe. The z-probe replaces the limit switch. You can leave the limit as a safety switch if you want, but you need to make sure that they are wired properly so that if either switch is tripped, you get a report of the Z end stop being triggered.
If the printrboard has the E limit switch, you can use that.
We tried a manual clip on probe with a switch in series but it was a pain. Same for the servo mount. Both worked but were unpredictable and complicated. Them we landed on a non contact sensor that senses metal and is permanently mounted-- no moving parts. It is poetry. Repeatable to .1 or .2 mm. We changed the firmware to power it through the z endstop plug on the printrboard. It’s awesome but requires a metal bed.
Is 0.1mm accurate enough? Thats the difference between a head crash and a good print.