I am building a CNC router using two 48" long Tolomatic belt drive actuators for the x axis. The actuators currently are using 1" wide 5M HTD rubber/fiberglass timing belts. After my initial tests I would really unpleased with the stretch in the belts. I am considering upgrading to a rubber/steel belt which should reduce stretch. The more I read about HTD belts the more that I learning that they are good for torque but not for positioning accuracy. I am considering switching to modified curvilinear (GT2) style belt but this would require I change my pulleys. Can anyone comment on the accuracy of timing belts and the different tooth styles (ie HTD, XL, GT2, etc).

Thanks!