This mod makes manually leveling the build bed a thing of the past.This is for Advanced users only, Firmware and hardware modification is required and likely will affect any warranty on the machine. This also reduces your X printable area by about 8mm, at the max X position.
video's of the prototype in action:
printing with Z motion http://youtu.be/c8dM1KpBXJ8
Inspired by this: https://www.matterhackers.com/news/automatic-printer-calibration-update
The Z-probe is a micro-switch wired up in parallel with the existing Z min switch and attached to a cam operated toggle. The probe is deployed when the X-carriage goes to the max X position, and retraced when the carriage goes to X0. This allows for automatic bed probing before each print.
NOTE: this is designed to work with TAZ's that have my stiffened X motor and bearing mounts. http://www.thingiverse.com/thing:107553 It can work with standard TAZ parts but may require a custom 8mm spacer on the lower X smooth rod since the probe is activated by pushing against these parts.
It is also recommended and probably necessary to remove the Z-backlash that is in the standard TAZ by following the instructions in this mod: http://www.thingiverse.com/thing:117950
BED PROBEING FIRMWARE:
Lulzbot TAZ specific configuration.h file:
G-code for probe deployment and bed probing:
be sure to do the anti-Z backlash mod first, and the stiffened X mounts (though this one may be optional, with an 8mm spacer on each side). links are in the sources or description
For best results, replace all 10mm linear bearings on the TAZ with LM10UU ball bearings.
-(3-4) M3 washers
-(1) M3x16mm bolt, longer should also work
-(2) M3x12mm bolts
-(3) M3 insert nuts and inserting tool(short, mcmaster carr)
-3mm drill or reamer
-(1) roller tipped micro switch (radioshack 275-0017 or other electronics store)
-Print all parts. ABS recommended. support material is not needed
-trim and/or file the bearing holder and activator so that the base of the bearing holder is flat, and the activator slides easilly in the slot.
-install 2 insert nuts in the toggle, and one in the bearing holder where the toggle mounts. It should be below the surface in the bearing holder, and not sticking out either side of the toggle.
-drill or ream the holes in the micro switch to 3mm (depending on the switch, this may not be necessary)
-Install the micro switch with the 2 12mm screws as shown in the pictures.
-Install the bearing in the bearing holder
-temporarily install the activator in the bearing holder
-temporarily install the toggle as shown int he pictures with the 16mm screw and washers. 2 or 3 washers should go in between the toggle and bearing holder and one on the outside of the toggle for the bolt to push on.
-test the operation of the toggle. it should take some force but not too much. be carefull, and adjust the toggle axis bolt tension or trim and file the parts until the move freely.
-remove the toggle and activator
-install the bearing block on the X-carriage, re-using the mounting screws from the original part.
-slide in the activator
-attach the toggle
-wire up the micro switch
-replace the Firmware
-calibrate the probe. see here for help: https://www.matterhackers.com/news/automatic-printer-calibration-update
-add the G-code to do the bed probing before each print
-remove the 4 springs from the bed corner mounts and never re-level your bed again.