Belts and Pulleys

Overview

• What they are:
  • A belt is a strong loop (like a rubber band) that connects two or more pulleys (wheels with grooves).
• What they do:
  • When one pulley turns, the belt wraps around it and makes the other pulleys turn too, transferring power smoothly between them. Pulleys on their own can also help lift things or change the direction of a pull.
• Pros:
  • Smooth and quiet
  • Can work over longer distances
  • Helps absorb shocks
  • Usually less expensive and easier to put together than chains or gears
  • Very little backlash
• Cons:

  • Can slip (loses some power)

  • Not as strong for really heavy loads as chains or gears

  • Belts can wear out

  • Fixed size belts length

    

Argos Standard

We use HTD 5mm belts and HTD 5mm pulleys with hex shafts. The standard pulley is 24 tooth.

• HTD stands for High Torque Drive. This means the teeth on the belt and pulley have a special rounded shape designed to handle power strongly and prevent slipping.

• 5mm refers to the pitch, which is the distance between the center of one tooth and the center of the next tooth on the belt and pulley.

  

How to Calculate Belt Center Distance and Size

Belt Calculator

Belt Calculator

Belt Calculator

Step 1: Select Inputs

Calculation Mode:Center Distance → Belt OptionsBelt Length → Center DistanceBelt Sweep Table

Pitch:5mm HTD (Argos Standard)3mm HTD

Belt Source:Any (All Sizes)WCP Stocked BeltsArgos Stocked Belts

Step 2: Input Pulleys

Pulley #1 (Teeth):

Pitch Diameter: 1.003"

Pulley #2 (Teeth):

Pitch Diameter: 1.504"

Step 3: Desired Center Distance

Desired Center:

Extra Center:

Ratio: 1.50:1

Step 4: Belt Options

Enter pulley sizes and center distance to see belt options

Pulleys are the Same Diameter

Center Distance(in) = (Pitch × (Belt_Teeth - Pulley_Teeth)) / 50.8

Where:

• Pitch = 5mm for HTD belts
• Belt_Teeth = number of teeth on the belt
• Pulley_Teeth = number of teeth on the pulley

Example

Belt: 70 tooth HTD 5mm belt
Pulley: 24 tooth HTD

• Pitch = 5 mm
• Belt_Teeth = 60
• Pulley_Teeth = 24

Center_Distance = (5 × (60-24)) / 50.8 = 3.5433 in

Pulleys Different Diameter or Non-Standard Routing

You will need to add up the loop distance of the belt routed over the pulley pitch diameter.

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Quick Reference Guide

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HTD 20 DP 5mm Belt

Stocked Sizes

Teeth	Quantity	Center Distance (in) (24 to 24 pulley)
60	18	3.543
70	11	4.528
80	16	5.512
90	12	6.496
100	14	7.480
110	2	8.465
120	10	9.449
130	1	10.433
150	6	12.402
160	6	13.386
170	2	14.370
180	6	15.354

Where to Buy
HTD Belts - West Coast Products

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1/2" Hex Shaft Pulley

Stocked Sizes Available teeth: 24

Where to Buy Hex Shaft Pulleys - West Coast Products

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Falcon Pulley

Stocked Sizes

Where to Buy
Falcon Pulleys - West Coast Products

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