Torxed
1
I’m not sure if this is the right forum, but I’m used to Stack Overflow and this looked sorta’ like it and said it was a Q&A forum for 3D printing. So here I go…
I’ve bought and built a Mini Kossel Delta printer.
I’ve printed a few things ~successfully. The general shape of the test square is, well a square. But the height of the object is off by 2mm and the layers appears squished:
So i recon I’d calibrate the height of the printer.
But whenever I do “Set Delta Height” under “Delta Calibration”, either I get “Err: ZPROBE” or the height doesn’t change. So I thought i’d change Configuration.h and the configuration says:
#define DELTA_HEIGHT 378.3
But after uploading, the printer says Z is maxed at ~374.6 (off by 0.1 from time to time)
I know for a fact that the print height is off by 4.6 exactly, because when the printer says it’s at 4.6 it will hit the print bed.
Bed levling also gives a ZPROBE error: August 29, 2017 - YouTube
The calibration guide I’ve followed twice now is: Kossel Delta Software, Marlin Firmware, and Calibration - YouTube
1: How do i get rid of “Err: ZPROBE”
2: How do i adjust for the incorrect print height offset of 4.6? (Configuration.h has little/no effect on height when changing DELTA_HEIGHT)
https://hvornum.se/Configuration.h
Torxed
2
So I fixed it.
According to all the guides, the measurement points were all off. “DELTA_RADIUS” was not the two points every drawing showed it to be. According to all the pictures and what not, I got my measurements to be roughly 120mm. Autocalibration and some other helpful tools in the later Marlin software versions gave me a DELTA_RADIUS of ~90mm. Once that was fixed, diagonal rods (DELTA_DIAGONAL_ROD) was also adjusted _very slightly_ to correct for any previous errors in measurements.
Once all that was done. The auto-calibration tool in the later firmwares also compensate for endstop adjustments (bed leveling). So i got those values through Repetier Host debug console and placed those in my configuration as well.
Now, the probe itself. I manually stepped the hotend to the glass hotbed until it just made contact. Then i stepped it some more until the auto-level relay “clicked”, which was about 0.5mm after the tip touched the bed. So I changed Z_PROBE_OFFSET_FROM_EXTRUDER to be -0.5. That still gives me “Err: ZPROBE” occationally.
And the extruder… Oh dear. it comes default set to 760*1.1 steps/mm which is insanely high. I literally don’t understand why it’s this high. Anyone knows?
It’s my bad for being a beta.jpg because I didn’t do the actual measurements. But this go around i took the time to mark the filament, heated up the hotend and stepped the extruder -10mm and measured how far the went. After doing so I found that 150steps/mm was a perfect fit for my gear setup (standard china cheap setup). So after lowering the extruder stepper values to almost 7 times less than default, the extrusion worked perfectly.
Finally, and this is probably the most important part. The “steps/mm” values on all axis were off my 20mm because, when using the online tool (or manually calculating) RepRap Calculator - Original Prusa 3D Printers - You’re supposed to input the number of tooths the pully gears have on all the axis that drives the belts. Well both the guide and my manual initial check on the gears got it to be 20 teeth per gear. A recheck actually gave 16 teeth. So instead of 80 steps /mm I had 100step/mm. That cleared up any height and travelissues I had.
