Question About Calibration of Extruder.

If i click 1 on the Repetier program for the Extruder Feed, does this mean 1cm will come out of extruder?
and the same for 5=5cm and 50cm and 100cm

was there a nozzle size specifier in the marlin configuration that i missed somehow?

i am using 0.4mm nozzle and when i click 5cm button about 8cm comes out and when i click 100cm about 180cm comes out.

should the flow be the same as i clicked it?

will this make my printed parts in accurate?

thank-you in advance

and also is there a way to change in repetier? offset the feed-rate to correct itself for printing.

and also is the a calculation the work out the offset percentage?

if 5 repetier feed=8cm actual feed
which also means
100cm repetier feed =180cm actual feed

A quote from another space - very helpfull !!!

"
Measure
Required tools: vernier caliper with depth gauge, or similar tool that can precisely measure 100mm. Your hob effective diameter is unlikely to be exactly 7mm.

Remove the hot-end from extruder so you don't waste filament.
Feed in some filament.
Using the extruder body as a reference point, mark the filament at 120mm.
Tell the printer to feed 100mm of filament.
Measure the distance from the extruder body to the mark you made. It will be over 20mm if it moved too little, under if it moved too far.

new_e_steps = old_e_steps * (100 / distance_actually_moved) … or, old_e_steps * (100 / (distance_to_mark + 80))

Set this value in your firmware. You may need to re-flash your board. Sprinter/Marlin supports M92 Ennn to set this value temporarily.
Repeat from Step 3 until you get between 96-104mm. Then continue with this guide. You'll dial it in perfectly later on.
Don't flash firmware yet. There's a further refinement to this value below. Why? The back-pressure from the hot-end alters how much plastic each hob revolution pushes, and you'll probably end up tightening your idler more which reduces the hob effective diameter.
Re-attach hot end.
"

CALCULATOR

Edited 1 time(s). Last edit at 09/03/2014 03:05AM by DBS.

You might not realise, but its 5cm of filament in to the extruder.
So when you calibrate you measure whats going in to the extruder not whats coming out of the nozzle.

Ok got it

i clicked 100 mm and got only 85, how would i change it in marlin to take into account this rate of flow?

changed feedrate from 600steps to 680, now it runs good