Anyone have any problems as to setting up a Kossel Mini? I still need to tune the motors, use OpenDACT or manual calibration, and start printing cubes…
Good choice on printer. I’ve used various kinds, and the Kossel Mini + that I built seems to work the most reliably. I respect the choices that other have made, by my personal experience has been positive. I’d suggest an auto calibration probe and a firmware that handles it for anyone building one. I like https://github.com/RichCattell/Marlin/tree/Testing 3 for the firmware, and the IR probe from maker DC42 is amazing, and distributed in the US through Filastruder: Mini differential IR height sensor - Filastruder 2. If your Repetier setup works, keep it. The probe has been amazingly accurate in getting my printer to pretty sick calibration, and I’ve had the bed off once or twice without even having to recalibrate.
I also love and recommend the Bondtech Extruder - it’s expensive, but I have yet to have any single issues with extrusion related to it. Once you get proper extrusion/retraction feedrate and E-steps dialed in, it’s extraordinarily reliable and even prints Ninjaflex through a 600mm bowden tube without any complaints.
It sounds like you’re going through the mechanical calibration and are interested or have purchased a probe, all of which will make for happy printing. The instructions left by Cello below are what I’ve seen used elsewhere and should get you very close. I found that the additional probe firmware calibration made things perfect. I’m not sure what your issue with delta radius is - it may be prudent to re-measure the parameters for whatever Repetier uses to calibrate it.
For calibration objects, I’ve done away with cubes for the delta and moved on to this object: Calibration Reuleaux Triangle by senormeow - Thingiverse 3. If it prints and the inside diameter is on and the point-to-point distance from each of the vertices is the same, you’re golden. If not, you can orient the object so that each point faces a tower and then are able to quickly identify if your rods or off or something’s not right otherwise with a tower offset calibration number. For delta radius calibration and tweaking, something like these concentric circles works (and also is helpful for getting the bed mechanically flat): Bed Levelling Spirals by clefranc - Thingiverse 1. If your radius is slightly off they will be noticeably different in height from the perimeter to the center, and any high-side on the bed will be obviously apparent. If it’s trying to drill your hotend into the center of your print bed, I’d get that fixed before trying these.
