Beginners luck!

omar221

@omar221 the probem is from the steps/mm when i set it to 500 instead of 128105,58 it works (with 128105,58 steps/mm when i extrude 10 mm i get 10 mm, i think the number is this big because i'm using a 30 to 1 reducer and 1mm pitch screw))

dc42

@omar221, that steps/mm value is much too high to be usable. Can you set the driver to a much lower steps/rev value?

omar221

@dc42 i've determined the steps/mm value by multiplying the old steps/mm by 10 and divided it by the amount it extruder and when i tested it when i extrude 10mm i get 10 mm
if i set it to lower i won't get the same result ,
with x256 Microstepping set in the firmware the lower i can get the driver is 800 pulse/rev and i still get the same speed for 60mm/s and 1mm/s

dc42

@omar221 changing microstepping in RRF won't work, because you are using an external driver. But your external driver may have several different steps/rev settings.

omar221

@dc42 yes it has i tried all of them from 200 to 2560 pulse/rev with no luck

omar221

This post is deleted!

omar221

@dc42 I think i found the solution i've set the step/mm to 80 the stepper work but there's a small problem when i extrude 10 mm i get less than that, so i need to extrude 400 mm to get 10 mm
is there any parameters to change like an extruder factor or a macro or something like that because i can't change the step/mm it will be too high because i'm using a wormgear reducer

thank you for your help

Phaedrux

Yes there is an extrusion factor you can set.

https://duet3d.dozuki.com/Wiki/Gcode#Section_M221_Set_extrude_factor_override_percentage

But is there not some setting on your external driver to change?

omar221

@phaedrux I can change the current and the pulse/rev
but i think the problem is that the step/mm is too high because i'm using a wormgear
like i said i can get the step/mm right it will be 280000 step/mm but i won't be able to change the speed

omar221

@phaedrux Finally found the solution if somebody have the problem
The surface of the 5 mm nozle is 2.5 x 2.5 x 3.14 ( Pi ) = 19 mm2 ( roughly )
Surface of the piston is 35 x 35 x 3.14 = 3846 mm2 ( roughly )
So one mm movement of the piston will give 3846 / 19 = 200 mm length output ( roughly again )
the the stepper dosen't have to move that far