custom printer, size of print 10 times smaller

bai_phoa

hello everyone, for my first post i'm akredy asking a question:

custom printer:

-printing size 920mm x 920mm  x 800mm

-steper NEMA24:130N.cm (8 motors )

-pulley teeth: 20 GT2 (GT2 for test because cheaper)

-pulley radius: 7mm

so for Y axis there is:

15kg, moved by 371N transmited by GT2 belt (yep heavy for it) with this we can calculate the acceleration: 24m.s-2 

so in config.h i have to set at 24000mm.s-2

5 steps / mm

and for X axis there is:

9.5kg, moved by 185N transmited by GT2 belt  so the acceleration is : 19.5m.s-2 -> 19500mm.s-2

5 steps /mm

all of that is set, but i'm looking for high speed move, because i can deposit enought plastic without problem (plastic pellets printer head 1760w) i can up the plastic flow to 7200cc.h so that put an other problem for later. 

i've set the non print speed at 500mm.s, filling speed at 250mm.s, to do that it's not the problem, with that config check many times i still have a problem, the printing size is wrong!

when i try to print a object with 800mm size, it put a lot of plastic in a 10-15 times smaller space.

for mesure it, i've put off my printer head and put a pen, and it draw it realy smaller never more than 60mm..

did someone have a solution for it.

thank you very mutch for help and to read my horrible english

Roko

steps/mm settings? 

seems like 5 steps/mm is too small. a rough guess is a factor of 13.3 too small, 

there are guides to calibrating sizes. 

hope that helps

Repetier

You get 4,7x steps per mm with full stepping. Better way is count pulley teeth, then multiply with 2 to get circumspehre. From your result you have either 8 or 16 microsteps set in driver, so set to 1600/pulley cirumspwhere