My Ender 3 pro board failed on me for some strange reason. I think the problem was that the extruder motor driver died. 2 of the 4 pins went straight to ground.
So now I have a Duet board. I have no problem understanding electronics and so forth, but G-Codes and such is way beyond my knownledge.
So far I have managed to home x and y without any problems. Both hit the endstops and work as expected.
Z is another story. Z has no endstop, but use a BLTouch. It works but I have to stop it with my finger because it tries to probe outside of the bed.
I can manually change it so it probes on the bed via homez and homeall, but when I press the mesh bed compensation it will probe outside of the bed again.
Do anyone have a working configuration for Ender 3 Pro + Duet + BLTouch? That would help a lot.
I am actually working on an Ender 3 for a friend of mine. I cannot imagine the differences in machine configuration being drastically different. I would suggest using the Z end stop on the top, that is what I am doing for now and up until this morning when I accidentally corrupted the sd card by trying to write to the bedmesh.g file.....while it was actively reading the bedmesh.g file, it was working extremely well and it is extremely precise.
Much of your results will depend on (1) How well you assembled it (2) how precisely you assembled it (3) how good you are at troubleshooting, calibrating, and tuning it.
My configuration will probably be about the best out of anyone using an Ender because I am a machine builder, I am a CNC machinist, I am a Perfectionist, and I have access to the measurement equipment to calibrate it extremely precisely.
Getting dimensional accuracy with a low-end 3d printer is not within most people's realm. In general, it is not easy. Luckily, Creality did a phenomenal job on the design, relatively speaking. It is, however, time-consuming. I calibrate extrusion with a micrometer and I check perpendicularity with an indicator that measures in ten-thousandths of an inch. I assemble it on granite because of the way granite countertops are manufactured (they are CNC machined, then precision "lapped" which is like wet sanding but more similar to grinding and polishing to get a shiny finish). Granite is VERY precise, the flatness is amazing, we use higher precision granite at work for inspection tables. If you don't have one already, get a 123 block (machined, then ground) from amazon or something and a Fowler, SPI, or Mitutoyo caliper. Amazon or MSC direct will do.
Assuming your machine is similar in the way it is assembled (your Z height will likely vary due to the change in the Y extrusion) then you could pretty much use my config and you'll only need to do a could things like calibrate your z endstop height from the bed, calibrate your bltouch trigger distance, and maybe your steps per mm may be off a tiny amount if the deviation in the steppers is drastic, but I doubt it'll be all that much.
The duet hardware alone just STOMPS the sh*tty ender board, there is literally no comparison between the two. The firmware....good god, you have no idea how good it is, how far ahead it truly is. Switching to the Duet is as good of a decision as buying the ender pro, but better because once you get to know the duet and RRF....you'll begin to understand just how much you can do with the boards and how much development actually went into and is still going into the duet ecosystem.
Since I corrupted my SD card this morning (luckily I had a backup from the night before) I lost a lot of the final config numbers, like the numbers you are asking for to avoid it going off the bed.
So you aren't super frustrated doing it yourself until I am finished, this should solve some of your problems:
G31 P500 X-41.5 Y-10.265 Z0.9 ; Set Z probe trigger value, offset and trigger height
This is the offset value in the X and the Y (both negative, as cnc offsets are ALWAYS relative to the spindle/tool head)
This is assuming you have the same BLTouch mount that I have, I can only go by what I have in front of me.
Where this file is located depends on your configuration. If it is a standard config file from the configurator tool, then the G31 value will be by the rest of your Z probe stuff about 3/4 of the way down.
I have a separate "bedmesh.g" file and call up bed.g file like this:
; bed.g ; called to perform automatic bed compensation via G32 ; ; generated by RepRapFirmware Configuration Tool on Tue Jun 26 2018 13:03:45 GMT-0400 (EDT) M561 ; clear any bed transform M98 Pdeployprobe.g ; deploy mechanical Z probe M98 Pmachine_bedmesh.g ; configure the bed mesh G29 ; probe the bed and enable compensation ; Probe the bed at 4 points G30 P0 X10Y30 H0 Z-99999 G30 P1 X10 Y220 H0 Z-99999 G30 P2 X175 Y220 H0 Z-99999 G30 P3 X175 Y30 H0 Z-99999 S4 M98 Pretractprobe.g ; retract mechanical Z probe
My bedmesh file just looks like this:
; machine_bedmesh.g ; February 18, 2019 ; This file defines the extent and density of the bed mesh. ; The way this is calculated is by taking the max X, subtract the Z probe X offset ; from it and use that as the second of the X values. ; For example, if max X is 383 and the Z probe X offset is -43, the parameter would be X0:340 ; For the Y parameter, make sure you don't start too far to the front or you will hit ; the bed clips with the hot end. Anywhere between 35 and 40 is probably a good start. ; The S parameter defines the distance between two mesh points in mm. M557 X0:175 Y20:220 S40 ; Define mesh grid M376 H15 ; Define height(mm) over which to taper off heightmap compensation
This should get you past the issue you are having now, is you are still going off the bed after this, bump up the X value in the M557 command found in my bedmesh file, or measure the offset in the X and Y value for your BLTouch mount and alter it in the G31 command, obviously left of the nozzle is negative, right is positive as it is relative to the spindle/tool head.
I'll upload the rest to my github when I am finished.