Pitch Diameter also known as PD is the circle that is formed while the belt and pulley are meshed together and which the belt rotates around. If you wish to find the PD, reference the formula below.
(Pitch x Number of T) ÷ π
The Outside Diameter also known as OD refers to the outside diameter of the pulley.
Pitch Length also known as PL is the length or circumference of a belt. If you wish to find the PL, reference the formula below.
T x Pitch
The Number of Teeth, T, is simply the amount of peaks that are around the pulley. If you wish to find T, reference the formula below.
PL ÷ Pitch
WCP now offers a built-in calculator to provide all our customers with piece of mind when designing with belts and pulleys. If you are interested in viewing our calculator or knowing how to use it, see below for more information.
Use this calculator to find the correct center to center distance for belts (WCP Belt Calculator)
You will need a few pieces of information when using the WCP Belt Calculator:
Belt pitch to be used
3mm for GT2/GT3 belts
5mm for HTD Belts
Number of teeth for both pulleys
Approximate distance between centers of the two pulleys
The Output from the calculator will give you the belt center to center as well as the tooth count for the closet belt to the values entered. It will also give you the information for one belt size higher and lower.
The equation below shows the minimum center distance that should be used.
The equation below shows the center distance for equally sized pulleys.
The examples below are places where a looser belt may be beneficial. Subtracting center distance can help reduce the overall load of the system which in turn reduces motor load and power consumption.
First Stage Reduction: -0.000 to -0.003
Intake Rollers: -0.015 to -0.020
Conveyor System: -0.015" to -0.020"
First stage reductions
Motor to flywheel
Low load
Intake or conveyor systems
Drivetrains
Medium load
GT2 timing belts are intended for lower load applications such as the first reduction in a gearbox, or motor to flywheel. GT2 belts use a smaller pitch than HTD belts, which means you can use larger reductions in those tight fit areas of your robot.
All GT2 Pulleys will now be clocked and engraved. An alignment notch has also been added to help with clocking multiple items together during assembly.
These pulleys are compatible with GT2 and GT3 belts.
Synchronous timing belts are lighter and more efficient than chain. Once set up, they require no tensioning or adjustment. The HTD profile is ideal for FIRST ® Robotics Competition applications - its deep tooth profile allows it to better handle high reversing loads, such as those found in an FIRST ® Robotics Competition drivetrain.
All HTD Pulleys will now be clocked and engraved. An alignment notch has also been added to help with clocking multiple items together during assembly.
| Bore | Width | # of Teeth |
|---|---|---|
| Width | # of Teeth |
|---|---|
| Width | Bore | # of Teeth |
|---|---|---|
| Width | # of Teeth |
|---|---|
8mm SplineXS
9mm/15mm
16
Falcon Spline
9mm/15mm
16
RS550 Motor/RS775 Motor/BAG Motor
9mm
12
1/2" Hex
9mm
24, 36, 48, 60
9mm
45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 140, 150, 160, 170,180
9mm/15mm
8mm SplineXS
12
9mm/15mm
8mm Key, Falcon
12
9mm
1/2" Hex
15, 18, 24, 30, 36
15mm
1/2" Hex
15, 18, 24, 30, 36
9mm
30, 35, 40, 45, 50, 53, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 104, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, 225, 250
15mm
30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 104, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 160, 170, 180, 190, 200, 225, 250
18mm
25ft
