Hello. I have a Taz 6 that I was trying to lubricate it’s rails. I brought the z axis to the top and when it reached the top it started to make some grinding noise so I shut off the printer. I turned the printer back on and now I’m not able to move the printer down in the -z direction. The Z position reads 0 even though it’s all the way at the top, I’m not able to move it down to a -z value, as it thinks the position is at 000. Moving it in the other direction causes grinding noise as the printer is at the top most position. I tried disconnecting the z max limit switch, no change. I tried disconnecting the connectors of the z max switch and shorting them together, no change. I tried flashing the firmware to hopefully clear the eeprom settings, no change. How can I get the z axis to move down again?
What were you lubricating with? Please tell me it’s not WD-40.
In addition to hitting a poorly-lubed spot on the screws, if the gantry gets too far out of level, due to one side binding, it can wedge the gantry into that spot, and you will have to help the motors get out of it.
With the machine off, you can manually turn the screws (as close to synchronized as you can) to lower the Z axis away from the limit switch, and if the motors had no problem getting it up/down there, the motors may be able to take over getting it back down so you can re-calibrate the gantry height at both sides.
The lubrication on my own lead screws wasn’t adequate and my motors couldn’t move up or down without some help. Of course, I find this out at the top of a large print, because I haven’t been tall things for a while. Manual twisting and then putting fresh white lithium on the screws cleared it up.
If using proper lubricant on the screws and re-leveling the gantry doesn’t fix it up, look into the squareness of your frame. A non-level surface can twist the frame, so that at the top of the Z-motion, that un-squareness is amplified enough that the pressure on the gantry can stall the motors.
I lubricated it with some Mobil SHC 007 grease. Its what the machine shop used to lubricate the CNC machines.
To get the Z-axis to lower I had to turn the z-axis stepper motors manually to get the tool head to come down a few cm, then I was able to home the axis and get the tool head to come down. I recalibrated the X-axis bar to make sure both sides are the same distance from the top of the frame.
So it turns out my Z-max limit switch does nothing. I moved the z axis up and I pressed the limit switch by hand while the z-axis is going up and the tool head does not stop, just keeps going up. I tested the continuity of the button and it is looking correct, open when not pressed and closed when pressed. Is there something I can do to fix this? Does this version of the firmware for Dual Extruder v2 even support stopping when the z-max switch is pressed? I have a Taz 6 Dual Extruder V2 running FW 22.214.171.124. Thanks for your help.
The Z max switch should be normally closed, so when pressed or not present, the firmware should see that as a ZMAX event. If yours is closed when pressed, it’s wired wrong. It should be connected to the outsides of the switch:
There may be some setting that causes an open-at-power-on limit switch to be ignored, in which case there should still be a soft limit on Z for 257.7mm
Unplug the ZMAX limit connector from the control board, and test button function from the connector itself to see that there isn’t a short in the wire somewhere. If it’s reporting correctly to the board, then it’s looking at the board itself as an issue. You could do a change of pins.h in the source code and recompile so that something the unused XMAX limit switch pins are used for ZMAX if you had to do further testing.
Hi. I checked the pins of the cable that goes to the MOBO and the button is acting like normal, closed when not pressed and open when pressed, however its still not doing anything when I press the button and move the z axis. Could my firmware have anything to do with it as I’m running the firmware for the dual extruder V2 and on that firmware the x max switch is disabled since the tool head doesn’t have that button on it.
On my TAZ 6, the Z-max switch is on the X gantry. With my Dual Extruder V2 with firmware 126.96.36.199 an M119 reports:
Send: M119 Recv: Reporting endstop status Recv: x_min: open Recv: x_max: open Recv: y_min: open Recv: y_max: open Recv: z_min: open Recv: z_probe: open Recv: ok P15 B4
Note that the last switch is labeled z-probe and that switch is used by G29 to detect the nozzle touching the corner washers. The Z-max switch on the gantry doesn’t “do anything”.
With the Single Extruder V2.1 and firmware 188.8.131.52 an M119 report is identical to the Dual Extruder V2 report.
With the Single Extruder V2.1 and Universal firmware 184.108.40.206.13 installed (and my finger on the z-max switch) an M119 reports:
Send: M119 Recv: Reporting endstop status Recv: x_min: open Recv: y_min: open Recv: y_max: open Recv: z_min: open Recv: z_max: TRIGGERED Recv: z_probe: open Recv: filament: open Recv: ok P15 B3
This leads me to believe that the switch works but the firmware isn’t configured to use it.
I have an LulzBot OctoGrab™ Magnetic Flex Bed v2 installed on my TAZ 6 and the bed surface is higher than the washers. Due to the geometry of the Dual Extruder V2, I can’t print anything because “the other nozzle” interferes with the G29. If I remove the Magnetic Flex Sheet then the G29 completes successfully.
I’m going to necro this because, why not. Most of ya’ll are pretty active around here.
The switch does nothing. My issue is when I print something very large in the Taz 6, something that takes up 99% of the height, the end gcode will move up 10 mm and that will result in a nasty crash to the top of gantry/frame. I have since changed the dimensions of the print area in Prusaslicer to be 5 mm less and then changed the stop gcode to only move up 2 mm. But I’m puzzled why the gantry keeps trying to move up when the limit switch is being pressed.
I usually prefer these limits to be hard set in the firmware (firmware I cannot get), but without a working switch you can command the printer to crash into the top of the frame. The only firmware I can get the code for is the one in gitlab and that one doesn’t work on the Taz 6.
I have a TAZ 6 and have successfully build the firmware from https://gitlab.com/lulzbot3d/marlin with a few tweaks of my own.
An alternative is https://github.com/drunken-octopus. You can join his Patreon and get access to prebuilt firmware for the TAZ 6 (and other LulzBot legacy printers) with most of the available tool heads and some popular addons (like a BLTouch).