Calibrating Extruder with a Budaschnozzle 2.0 and 0.15mm Noz

General Hardware
#1

Can someone provide me with some guidance on getting the extruder calibrated for a 0.15mm nozzle.
I was able to dial it in on a 0.35mm nozzle use the OHAI Instructions. http://ohai-kit.alephobjects.com/project/extruder_calibration/

I started out extruding 100mm at 100mm/min with the 0.15mm nozzle. With the 0.35 nozzle I was calibrated with an Estep of 863, so I backed it down to 750 and the hobbed bolt just ate the filament. I assumed that I was trying to push too much through the small nozzle so I dropped it way down to 300 on the Estep and was able to get it to extrude with out the bolt chewing up the filament.
So with the temp at 230C 100mm /100mm/min I started extruding, trying to get to 100mm
Estep 300 Extruded 32mm
Estep 325 Extruded 38mm
Estep 375 Extruded 51mm
Estep 425 Extruded 60mm
Estep 480 Extruded 72mm
Estep 525 Extruded 75mm
Estep 550 Extruded 68mm ( I think here I’m taking to large of a step and the nozzle is backing up)
Estep 600 Extruded Bolt ate the filament again.
So seeing that I was moving in the right direction but couldn’t get a large enough Estep to give me the 100mm extrusion without the hobbed bolt eating the filament I decided to only extrude 50mm at 50mm/min
Estep 600 Extruded 30mm
Estep 650 Extruded 70+mm (It printed past my mark)
Estep 625 Extruded 32mm (Ran it twice 32mm both times)
Estep 640 Extruded 34mm
Estep 660 Extruded 37mm
Estep 700 Extruded 37mm
Estep 750 Extruded 51mm (Over shot by 1mm)
Estep 745 Extruded 38mm
Estep 749 Extruded 40mm
Estep 755 Extruded 42mm
Estep 775 Extruded 49mm
Estep 778 Extruded 38mm??? Reextruded 40mm (Magically Lost 9mm of extrusion)
Estep 780 Extruded 41mm
Estep 800 Extruded 55mm
Estep 790 Extruded 34mm?? Lost 20mm of extrusion, Reextruded 70mm+ extruded past my mark, 3rd time 41mm
Estep 775 Extruded 25mm Reextrude 40mm Reextrude 40mm

So needless to say after 2.5hr of trying to get it to behave and zero in the extruder I gave up. Does anyone currently use a 0.15mm nozzle if so what is your Estep value?

#2

Howdy,

As far as I can tell, your extruder steps should not change based on the nozzle diameter… The steps calibration depends on the micro steps setting on the rambo board, the step angle of the motor, the gear ratio (ratio between the small and the large herringbone gears) and the diamenter of the hobbed bolt - maybe the filament diameter could affect it very, very slightly. The calibration is made based on the amount of filament that goes INTO the extruder, not out of the nozzle :slight_smile: So the smaller nozzle will extrude a much longer bead of plastic with the same amount of steps, but again, the calibration should not change.

The smaller nozzle will definitely make it MUCH harder to extrude the plastic… Going from 3mm to 0.15mm means a lot of pressure to extrude the plastic at any significant speed - hence the trouble you’re having with missed steps and/or the hobbed bolt digging a hole in your filament… You will also want to play with the filament diamenter and flow settings in Slic3r to make sure your extruded plastic comes out with the proper thickness and width.

#3

I went from a 0.35mm to a 0.15 so I roughly cut my nozzle size in half.

Sorry I don’t think I was clear on my first post. The values I have listed as extruded is what went INTO the extruder. I understand that a smaller nozzle would have to make a longer string of filament. Plastic in=Plastic out.

I’ve measured the filament with calipers and averaged the value so I feel that its pretty close. Can you tell me more about these flow settings?

#4

I would return your esteps value to 863.

You’ll want to drop your extruder speed (manual and in Slic3r) to a much slower speed, say 30 for now and try a test print/manual extrusion. You may also want to increase your printing temperature slightly, say 232 or so.