timing belt and pulley

[Boyan Silyavski]

HTD 5M 15mm wide is the standard belt size most people on this and other forums use for nema 23 and 34 motors and servo motors.

20t pulley is the perfect balance of size, teeth in mesh, torque, limiting space and speed, etc...

20t:20t for 1:1 is perfect. 20:30 for 1:1.5 is perfect, 18:36 for 1:2 is perfect

where according to me 36t is the limit for large pulley and the same time fast machine. for ratios 1:3 and bigger, additional considerations must be made, inertia, weight, motor type and speed, acceleration desired, teeth in mesh, etc...

The best and most correct belt calculator. Where if say 100mm is calculated distance even a bare 102-103 mm will tighten the belt excellently, especially important where you have servomotors in play which have quite wide central part that limits the adjustment possibilities of mounting holes, though an additional plate for an additional adjustment can be fashioned

manufacturers recommend ~6t in mesh at least for that belt. where doubt arises due to weight or speed, more belt info should be read and check spec tables for the correct belt choice.

When i say "perfect" above, i mean long belt life, low inertia, not pushing the belt to its limits.

Hope that helps