The smooth (round) belts have a Durometer hardness of A70 and can withstand temperatures from -35 to 250 degrees F. Both the 1/8” and the 1/4” belts work excellent with our smooth hub pulleys*. Their elastic nature allows them to apply tension on the pulleys when stretched and the rubber construction creates excellent grip characteristics between the pulley and belt. Smooth belts can be used in a variety of applications including follow focus systems, linear drives, 90 degree drives, XY tables, robot tracks, battery hold-downs, etc. *When running inside of channel, the 1/8” belt must be used in conjunction with the 1” diameter smooth hub pulley to properly clear the channel wall.
The 1/4” smooth belts have a stretch factor range of 4-16%.
A low stretch factor will apply a small amount of side-load to the axles and create less friction while a higher selected stretch factor will apply slightly more side-load to the axles and have more resistance to belt deflection.
To figure your approximate belt length, the following formula can be used:
Db = [(2La + 0.5pi(D1 + D2) + (D1 - D2)2 / 4La) x (1 - Sf)] / pi
Db: belt diameter
La: distance between the centers of the pulleys
D1: diameter of pulley #1
D2: diameter of pulley #2
Sf: Stretch factor