Belts (Timing, Polyurethane)

Timing belts work in a similar way to chains, except there are pros/cons that make them more useful for certain applications than others. Below are some pros/cons for timing belts.

First of all, belts come in 2 main varieties, there are GT2 belts, and HTD belts. Basically, the HTD variety of belts is a little bit bigger in size and is able to handle more load. Most applications, such as intakes, rollers, etc., work well with either choice. Some HTD sources are lower priced though, so that can factor into the decision.

In order to design with belts, first decide if you want a reduction from the belts. It works the same way as a chain, a smaller pulley to a larger pulley would reduce the speed and increase the torque. A lot of pulley sizes are available on vex/wcp/andymark, but for cases where you need a specific size, it is possible to make your own pulley and 3d print it. The custom pulley template file is here: https://drive.google.com/open?id=1V20gBSk1BTdx9tJyBxouhtSXlx6qvgTi .

The file to make your own timing belt is here: https://drive.google.com/open?id=1dbGXd2BMeDrgdHg2dY48rRe5V3ZfEOs3 .

Once you know your pulleys, you can find the center distance and what belt you would need to use. Use the belt center distance calculator below to find the center distance as well what size belt you would need.

Link to belt center distance calculator: https://www.technobotsonline.com/timing-pulley-distance-between-centres-calculator.html

WCP page with belts and pulley information:

GT2: https://www.wcproducts.com/belts-chain-gears/belts-pulleys/gt2-timing-belts-and-pulleys/gt2-timing-pulleys?___SID=U

HTD 9mm: https://www.wcproducts.com/belts-chain-gears/belts-pulleys/htd-timing-belts-9mm/htd-timing-belts-9mm-width?___SID=U

Sample images of using the above calculator: