Velleman Vertex K8400 Precise Pulleys

This pulleys give me more precise printing, nearly without backlash issue. In addition I tested them with TMC2100. Due to gear ratio 14 : 24 they give less load to TMC driver, It could produce maximum 1.7A . This combination prints nearly noiseless.

I have those setting in Merlin firmware:
\#define DEFAULT_AXIS_STEPS_PER_UNIT {115.49, 115.49, 4266.66, 150 }

(200\*16)/(19\*2.5)\*(24/14) = 115.49
200 - 1.8' stepper motor (360' / 1.8' = 200)
19 - teeth on pullesy
2.5 - belt type (2.5mm be