Here are the details:
- Enter the following scripts into the G-code popup menu in Repetier-Host.
Script 1:Script 2:Code: Select all
; Home, then go to a point right in front ; of the X tower, with the delta arms to the X Cheapskate ; vertical, and at a Z position of 2.0. For measuring ; the X tower end stop error. G28 G0 Z10 X-104 Y-60 F10000 G0 Z2 F1000Script 3:Code: Select all
; Go to a point right in front ; of the Y tower, with the delta arms to the Y Cheapskate ; vertical, and at a Z position of 2.0. For measuring ; the Y tower end stop error. G0 Z10 F10000 G0 X104 Y-60 G0 Z2 F1000Script 4:Code: Select all
; Go to a point right in front ; of the Z tower, with the delta arms to the Z Cheapskate ; vertical, and at a Z position of 2.0. For measuring ; the Z tower end stop error. G0 Z10 F10000 G0 X0 Y120 G0 Z2 F1000Script 5:Code: Select all
; Go to a point centered over the bed, at a Z ; position of 100. For safely adjusting the ; limit screws. G0 Z10 F10000 G0 Z100 X0 Y0Code: Select all
; Go to a point centered on the bed, at a Z position ; of 2.0. For testing the horizontal radius error. G0 Z10 F10000 G0 X0 Y0 GO Z2 F1000 - Set the end stop screws to the middles of their range, as shown in the MAX v2 manual.
- Find the proper Z max length as in the MAX v2 manual. Then, enter this value PLUS ONE into the "Z max length" field of the printer's EEPROM. This will shift everything down one millimeter, so that you'll be calibrating the bed to Z=1 rather than Z=0. Yes, this means Z=0 would whack into the glass, but you won't be going there.
- Heat up the bed and extruder to a typical temperature.
- Run script 1, which will home and then go to right in front of the X tower, at a height of Z=2. (This should be 1mm above the bed, but it won't be because of the error that has yet to be calibrated out.)
- In Repetier-Host's Print Panel, use the Z axis manual control to bump the extruder down by 0.1mm at a time until a piece of paper between it and the glass drags as its pulled.
- Read the Z position displayed in Repetier-Host, subtract 1, and write it down as the X tower error. If the value is negative, then you had to bump the extruder down too far, which means the X Cheapskate started too high. If the value is positive, then you weren't able to bump the extruder down far enough, which means the X Cheapstake started too low. (Note: do NOT adjust anything yet!)
- Run script 2, which will go to right in front of the Y tower, at a height of Z=2. (Note that the script does NOT have to home, which speeds things up a lot.)
- As above, bump the extruder down until it pinches your paper, read the Z position, subtract one, and then write it down as the Y tower error.
[*}Repeat again with script 3 and the Z tower, writing down the results as the Z tower error. - Run script 4, which moves the extruder away from the bed so you can safely adjust the end stop screws. Then, adjust the three end stop screws. The end stop screws have 32 threads per inch, so, one rotation moves the head 1/32", or 0.79mm. Call it 0.8mm, so that every 0.1mm of error means you turn the corresponding screw 1/8 turn. A negative error mean you need to lower that Cheapskate's home position, so unscrew the end stop screw 1/8 turn per 0.1mm error. A positive error means you need to raise that Cheapskate's home position, so screw in the end stop screw 1/8 turn per 0.1mm error.
- Go back to step 5 and do it all again. If you're lucky, you'll find everything completely calibrated; if not, go one more round.
- When everything is calibrated, run Script 5 to move the extruder to the middle of the bed, and then bump it down until it touches the paper. Hopefully you'll now be at a Z position of 1. If not, you'll need to adjust the horizontal radius and then go back to step 5 again. (I don't know the formula for this, so I can't do better than trial and error; does anyone know how to do better?)
- Once everything is calibrated, go back into the EEPROM and restore the "Z max field" to its proper value (subtracting one).
Thanks,
Dan
