Signs of Worn Tracks and Wheels

A robot that slips, drifts or stalls isn't always asking for new tracks. But tracks are a common cause, so check them with the unit out of the water and unplugged.

Signs that point at the tracks or wheels

• Slipping on walls. One maker says that if the robot "slips on the walls, slides back down before reaching the waterline or gets stuck in corners, the tracks or wheels have probably lost grip"¹.
• Drifting to one side. A unit that "constantly drifts to the same side" often has uneven wear between the two tracks¹.
• Flat tread and cracks. Look for "Flattened tread, cracks in the rubber, excessive play between the track and the drive wheel, or missing pieces of material"¹.
• Stretching. One FAQ lists cracks and stretching among the signs to look for².

Check by hand

• Power off and lift it out. A service guide for one maker has you set the unit down on a flat surface before any inspection³.
• Turn each track. The tip is to "Take the robot out of the water and turn each track by hand"¹. A track that slips on the drive wheel points to wear.
• Spin independent wheels. Each should turn freely. Stiffness or blocking can mean "a seized bearing or dirty axle"¹.
• Compare the two sides. One side that looks worse than the other fits the drifting clue above.

Clues that it isn't the tracks

If the tracks look intact, the same source says to check the brushes and the filters. Excess debris can slow movement, and "a saturated filter reduces the power available for traction"¹.

• One track stops while the other runs. On a belt-and-pulley design, this is "almost always a problem with the belt, pulleys, or bearings on that specific side", and not the motor³.
• Skipping or on-and-off movement. On that same design, a missing belt cog lets the belt skip, so the tracks "slip or stop intermittently"³. Your robot may be built differently.
• Humming but no movement. Think motor. See drive motor basics.
• Poor cleaning but normal movement. Look at the brushes, and work through the brush signs.

Loose is not the same as worn

• A loose track can sometimes be tightened. Some slack can be adjusted out on many models, without a new track¹. Don't loosen or tighten anything until you've read your manual's steps.
• Don't grease axles unless the manual tells you to.

What to do next

• If the tread is flat, cracked or missing pieces, plan on a replacement. One FAQ says that replacing worn tracks promptly helps with "traction, wall climbing, and effective scrubbing performance"².
• Get the model name and part number first. Finding the right replacement part shows where to look.
• For a picture of how the parts fit together, read the drive system page.
• If you can't find the cause, ask the maker or an authorized service center. Don't open a sealed case yourself.