Ok, now I’m really frustrated: three days of work, and this is the result; the problem of the sliding layer has presented again, unfortunately not so often that I find the cause; I do not know what to think, below list the settings of my Kossel:
Engines Wantai 2.5 A, A4988 adjusted to provide 1.8 A
The three belts are regulated in the same way, I hope you can understand how looking at the attached video
Marlin Marlin-V1 (found by chance, I do not have a valid reason to choose this version)
Retraction extruder 4 mm
Z lift the retraction 1 mm
Speed: perimeters 80 mm / sec; external 60%; first layer 50%; infill 120 mm / sec, 50% solid, solid top 50%; travel 120 mm / sec
I print using the USB connection, because it could not find a version of Marlin that it does not cause compile errors enabling support SD and the LCD (any advice about the version of Marlin to use will be well appreciated)
Do you have heatsinks on the drivers? Also having a fan help cool the ramps helps. Then in config.h what are your jerk settings? I found mine way too high.
try a simple test print (square, ball, triangle). It’s not something you’ll get right off that bat (least in my case). It took me like 2-3 months and having time to play with mine.
I’ve been having a mechanical problem in mine due to lower temperature in the house. Parts will warp on a layer slightly until the hotend catches and skips a few steps because the belt slips. I need to make an enclosure to minimize this effect on my machine.
Are you using slides? I had a problem with slides jamming and causing layer slip. Also if it’s a kossel mini I have marlin with LCD and SD that compiles on arduino 1.0
What @Thomas_Sanladerer said is probably true (he’s quite knowledgeable about stepper drivers). Also, 80mm/sec is also pretty fast, and your steppers may be missing steps if they are encountering too much resistance (either friction or inertia). Try the same print at half that speed (40mm/sec).
Even under ideal circumstances, A4988 max out at 2A, the tiny stepper boards are quite far from ideal for heat dissipation. If your drivers aren’t burning hot, then your Vref current setting probably isn’t right for the sense resistor. Dial it up a bit and try again.
thank you everybody, Jeff, I’ll invesigate about the right Vref; problem solved : it seems the cause was an incorrect working of power supplier, may be some interruptions or falling down in output; I change it with another - similar but not the same, this has a fan - and I can print for hours without that problem; I hope to be right, regards
