Reliability Tips

November 2002

A stroboscope is a wonderful diagnostic tool for belt drives. With a stroboscope light you can:

Read the original belt’s number & manufacturer without stopping the machine: Run the strobe at the belt’s speed and the label and manufacturer will “stop”.

See if one in a series of belts are slipping: Shut down the equipment, chalk or paint a mark across all belts, start the equipment, calibrate the strobe to the running speed of the sheave, a slipping belt will slow down and separate from the others.

Check multi-belt drives for misalignment: If, the belts from the example above, present a step type pattern, the sheaves are misaligned. . The belt with the most load slips the least.

Check if the belt is worn out (v-belts): Shine the strobe at the sheaves. Check for shiny groove bottoms, which mean that a belt, or the sheave is worn out and the belt is riding on the bottom instead of on the walls.

The methods above require that you have “see though” guards, an inspection lid or inspection hole(s). For greatest visibility, the guard cover should be of expanded metal painted matt black and the sheaves and inside of the cover in two contrasting bright colors. With this configuration the guard cover will become “invisible” in strobe light. As always, please make sure you observe applicable safety regulations &procedures and work safely.