Suction cups, brushes and filters are the three wear items that decide a skylight robot’s reliable life. Cups typically need inspection every 20 to 30 operating hours, brushes every 50 to 80, and filter cartridges every 100 to 150 hours or sooner on hard water. Skip these and the first symptom is often a suction failure at height.
How do you care for suction cups?
Cups are the single most safety-critical part on the machine. They grip glass by pulling a vacuum against a thin film of air, and any nick, grit or glaze of dried sealant breaks that seal. After every shift, wipe the cup rims with a soft cloth and check for cuts, hardening or embedded grit. Early in a cup’s life the rubber is soft and grips well. As it ages it hardens and loses elasticity, and the vacuum margin shrinks before anything visibly fails.
A cup that needs to be pushed flat by hand to seal is a cup that has reached the end. Replace cups in sets, not one at a time, because uneven cup height tilts the chassis and loads the others.
What kills cups fastest?
Three things. Gritty glass near construction or roads acts like sandpaper. Solvent-based cleaners dry out the rubber. And direct sun on stored cups cracks them. Rinse and dry the machine after use, store it out of sunlight, and avoid aggressive chemicals. Those three habits alone can double cup life.
When do brushes and pads need replacing?
Brushes do the actual cleaning, so their condition drives the finish. A worn brush stops lifting the film of grime and starts smearing it, which is why a machine that used to leave a clean pane suddenly leaves streaks. Check bristle length against a new brush. When you have lost roughly a third of the length, replace. Pads on soft or coated glass follow the same rule, and glazed panes wear pads faster than plain ones.
| Component | Inspect every | Typical replace | Failure symptom |
|---|---|---|---|
| Suction cups | 20-30 h | 300-500 h | Suction alarms, slipping |
| Main brush | 50-80 h | 200-400 h | Streaky finish |
| Microfibre pads | Every shift | Weekly on coated glass | Smearing, poor pickup |
| Filter cartridge | Weekly | 100-150 h | Spots, reduced spray |
| Battery | Cycle count | 2-3 years | Short runtime, slow charge |
Why does water quality matter so much?
Hard water leaves mineral spots that look worse than the dirt you removed. Your filter is the line of defence, and it works only if you change it on schedule. In hard-water regions, cartridges clog faster and may need replacing at half the nominal interval. Some operators add a small inline softener, which pays back quickly if it saves one re-clean across a large roof.
Rinse lines and nozzles matter too. Nozzles that partially clog spray unevenly and leave dry patches that the brush then smears. A five-minute nozzle soak during weekly cleaning prevents most of this.
What does a sensible weekly routine look like?
- Wipe and inspect all cups; note any hardening or cuts.
- Rinse the filter and check spray pressure across the full bar.
- Inspect the brush for missing bristles and even wear.
- Check the tether and its anchor for fraying or corrosion.
- Run a suction test on a clean sample pane before sending the machine up.
Who should do this? Any site with trained operators, without question. Who can skip it? Nobody, really. If your team cannot spare 20 minutes after each shift, the machine will fail early, and the failure will not be gentle. A suction fault at height is the one problem you never want to discover on the roof. For parts planning, see the maintenance overview and reach the team via the contact page.
How long does a full service take, and who can do it?
A routine after-shift check takes 15 to 20 minutes. A monthly deeper service, replacing worn cups and flushing the water system, runs one to two hours. Any competent operator can handle both with the manufacturer’s guide. What they should not attempt is motor or control-board repair, which belongs with the vendor. Mixing those two categories of work is how a small wear issue becomes an electrical fault.
Keep a simple logbook. Record operating hours, cup changes, brush changes and filter changes, and note any suction alarm. That log turns a vague ‘the machine feels weaker’ complaint into a clear signal, and it is exactly what a technician needs to diagnose a fault fast.
What is the most expensive mistake owners make?
Delaying cup replacement to save a few hundred dollars. Cups are among the cheapest parts on the machine and the most safety-critical. Running hardened cups to squeeze out extra hours is a false economy that risks a drop, a damaged machine and an injury. If the cups feel stiff or need a push to seal, stop and replace them. That decision costs less than any incident it prevents.
What spare parts should every owner keep on site?
A small on-site kit prevents most downtime. Keep one full set of suction cups, one spare brush, two filter cartridges and a spare set of microfiber pads. That covers the wear items that fail first. For a site running the machine weekly, that kit costs a few hundred dollars and saves a lost service day the first time something wears out mid-job.
Keep the parts dry and out of sunlight. Rubber that sits on a hot shelf is already ageing before it touches glass, so store cups in a closed cupboard, not on a sunny rack.
Key Takeaways
- Inspect suction cups every 20-30 hours and replace in full sets.
- Worn brushes smear instead of cleaning, so watch bristle length.
- Hard water shortens filter life; change cartridges early in those regions.
- Never store cups in direct sunlight or clean with solvents.
- Run a suction test before every deployment.