Hello everyone,
I built a cnc/3d printer out of 2040 t-slot aluminum
It's intended for light cnc work, engraving mdf or acrylic.
The design is similar to most of 3d printers with dual nema 23 steppers z axis
Nema 17 for both the x and y
For the cnc electronics i'm using a bob with parallel port and single axis tb6560 for both x and y
and tb6600 for the dual z steppers
I'm using bearing blocks and smooth shafts for all axes with gt2 belts and 20 teeth pulleys on the steppers
After completing the build and wiring I started caliberating the motors in mach3
The problem is with the x axis
the micro stepping is at 1/8 and it should be 40 steps /mm
After using auto caliberation function in mach3 and measuring the travel with a ruler ,every time I get a different travel
I tried tensioning the belt, loosening, vibration dampners for stepper, switching nema 17 motors,using nema 23 stepper ,switching drivers, changing idler nontoothed pulley with a toothed one abnd even using a new parallel cable. Still I get different reading every time I caliberate
I did a few test pieces on plywood and the piece came out with deviations in the x axis which are not consistent
Is the problem with the design or what
I have been trying to fix it for over a month to no avail.
Thanks.?Click image for larger version. 

Name:	IMG_20180508_024610.jpg 
Views:	1 
Size:	72.3 KB 
ID:	392656