Calibrating Geared Extruder (1 reply)

Rostock is now doing the right things, thanks to all the help from this forum. Now trying to calibrate the geared extruder by measuring the filament.
Using 'Triffid Hunter's Calibration guide -
After a pronterface manual extrude of 100mm, I get 16mm through the extruder.
My 'E-Steps from my delta marlin 'configuration_adv.h' seems to be is 836 (see below)
======================
#ifdef ADVANCE
#define EXTRUDER_ADVANCE_K .0

#define D_FILAMENT 1.75
#define STEPS_MM_E 836
#define EXTRUTION_AREA (0.25 * D_FILAMENT * D_FILAMENT * 3.14159)
#define STEPS_PER_CUBIC_MM_E (axis_steps_per_unit[E_AXIS]/ EXTRUTION_AREA)
=========================
using this formula:
6) calculate new_e_steps = e_steps * 100mm / measured_distance
I get a new E-Step figure of 5225 . . which seems very high (and four digits)
have tried changing the E-Step number in 'config_adv.h', then recompiled and uploaded to printer . . with negligable change in extruded filament.
Was going to reflash firmware with an 'M92 Ennn' command but that needs a three digit number and I have 5225.
Can anyone tell me how to get the extruder to pass 100mm (instead of 16mm) when I ask for 100mm in pronterface?