Set e-step bmg

luc

Hello guys,
I have a doubt about the steps for the BMG Extruder (1.8degree engine).
BMG indicates to adjust the steps to 415 but to have 15 cm of extruded wire I have to adjust them to 440. Consequently, to have the wall at 0.45 I have to reduce the flow to 0.94%.
I made these settings with e3dv6 mounted.

The doubt is:

Maybe I have to do it with e3dv6 disassembled?
Do I have to adjust the steps to 415 (as BMG says), do not test the 15 cm of extruded wire and then adjust the flow to obtain 0.45mm?

Sorry if my english is not correct

Many thanks
Luca

ChrisP

I run a Bondtech BMG with their supplied 1.8degree stepper on my main machine.
With the standard x16 microstepping, my steps/mm is set to 410 and the extrusion width is bang on.

I'm not sure if I'm misunderstanding you, but your first statement implies you're having to increase the steps/mm to get the required extrusion, but your second statement suggests you're having to reduce the flow to prevent over-extrusion??

To calibrate your e-steps if you have a bowbed setup, remove the bowden tube, trim the filament at the end of the tube and slowly (10mm/s or so) feed 100mm of material. Trim off the material at the end of the tube again and measure it.
If you have a direct drive, then heat up the nozzle and put a piece of tap on the filament on the input side of the feeder that is just over 100mm away from the input and measure from the tape to the feeder. Again, a slow extrude of 100mm and re-measure.
RichRAp did a good explanation here a few years ago.

Get your e-steps right first, then worry about whether your extrusion width is correct later.

droftarts

@luc as @ChrisP says, don't worry too much about the actual step number (that's down to manufacturing tolerances, how soft your filament is, and/or possibly how tight you have the idler), just make sure it's extruding a consistent length. Then you have a baseline to set other extrusion factors, including flow. These can be dependent on the exact diameter of your filament, and speed of extrusion. Then flow rate is easier to adjust than the steps per mm of the drive.

Ian

luc

Then, it is a direct system. I try to explain myself better:
A hot hotend to extrude 15 cm I had to set 440 extruder step while bmg recommends 415. This is the first doubt: Is this right or do I necessarily have to set 415 as the data must be considered fixed?

@droftarts said in Set e-step bmg:

Then flow rate is easier to adjust than the steps per mm of the drive.

Ian

This is a new topic for me, where can I study regulation? Is there a guide?

Thanks everyone for the answers

droftarts

@luc see the guide here: https://duet3d.dozuki.com/Guide/Ender+3+Pro+and+Duet+Maestro+Guide+Part+4:+Calibration/40#s165

Ian