Summer maintenance for your robot mower: fresh blades and a clean machine keep your lawn healthy

Summer is a busy season for robot mowers, and it is easy to forget that a robot mower also needs maintenance. The good news is that robot mower maintenance is simple and takes only a few minutes a week. A little regular attention ensures the lawn stays healthy and green and the mower runs smoothly all season.

Why does blade sharpness matter so much?

A sharp cutting blade slices cleanly through a blade of grass. A dull blade does not cut - it tears and chops. The ends of torn grass blades dry out and turn brown, and within a few days the whole lawn looks yellowish and unhealthy. A torn tip is also an open wound through which fungal diseases can more easily attack the lawn.

A dull blade also affects the mower itself. Tearing takes more energy than a clean cut, so the battery drains faster, the mower covers less lawn per charge and returns to charge more often. Operating noise also increases noticeably. If your robot mower has become louder than usual or the lawn looks ragged after mowing, the first thing to check is always the blades.

How often to change the blades

For robot mowers with small pivoting razor blades, such as EGO Aura and STIGA models, manufacturers recommend checking the blades once a week and replacing them as a rule every 6 to 8 weeks. This is an average recommendation - the actual rate of wear depends on several factors: the size of the mowing area, the type of lawn and the mowing schedule, but also the ground. Sandy soil wears blades considerably faster, as do cones, branches, stones and toys left on the lawn. Spare blades for EGO robotic mowers can be found in our online shop. For the EGO Aura, the time remaining until blade replacement can be conveniently tracked in the mobile app.

The STIHL iMOW keeps track of blade running time itself and shows a message on the display when it is time to replace them. Here too, bear in mind that blades wear faster than usual on sandy ground and in a dry summer, so do not rely solely on the machine's reminder - check the cutting result with your own eyes as well. In our online shop you will find Cutting blades for iMOW 3, 4, 5, 6 and 7 and for older RMI series models iMow 422 and 522 blade and iMow 632 blade.

Two rules, however, apply to all makes. First, robot mower blades are never sharpened - they are always replaced with new ones. A sharpened blade loses its factory balancing, and an out-of-balance cutting system causes vibration and noise and wears the bearings. Second, all blades and their fixing screws are always replaced at the same time, as one set. A used screw can start to loosen under a new blade, and a loose blade is a serious safety hazard.

How to change the blades safely

Replacing the blades takes only a few minutes, but the safety rules must always be followed. First stop the mower and switch it off completely - depending on the model, either with the power button or by removing the safety key. Put on work gloves, as the cutting edges can be sharp even on a worn blade. Turn the mower upside down on a soft, clean surface – for example on the lawn or an old blanket, so as not to scratch the housing.

The blades are fixed with screws for which an ordinary crosshead or flathead screwdriver is sufficient. Remove the old blades and screws, fit the new ones and check that each blade rotates freely around its screw. Also inspect the blade disc the blades sit on. If it too is worn or damaged, the disc must be replaced.

Regular cleaning

In summer it is worth cleaning your robot mower once a week - for example at the same time as you check the blades. Before cleaning, switch the machine off and let it cool for a few minutes.

A damp cloth is enough to clean the housing; use a mild soap solution if needed. To clean the underside, turn the mower on its side and remove grass debris from around the blades and under the base with a brush. Dried-on grass can be removed with a wooden stick or spatula, which will not scratch the plastic. Be sure to clean the wheels as well, because grass built up around the wheels reduces grip, and the mower will start to slip on slopes and scrape along lawn edges.

On models with camera-based navigation, such as the EGO AURA, it is important to keep the camera lenses clean. In a dry summer, dust and pollen collect on them, and a dirty lens directly impairs the mower's ability to navigate.

Just as important as the cleaning itself is knowing what not to do. Never wash a robot mower with a pressure washer or under running water, nor with a garden hose (the EGO Aura is an exception - see the user manual for details or ask a Saemeister sales specialist). Water can reach the electronics, and such damage is not covered by the warranty. Solvents and aggressive cleaning agents that damage plastic surfaces are also unsuitable. Even for machines with a high moisture-resistance rating, the manufacturer's official maintenance advice is always the same: a damp cloth and a soft brush.

The docking station also needs attention

Before cleaning the docking station, pull the power plug out of the socket. Remove grass, twigs and other debris from the station and around it that could prevent the mower from entering the station. Inspect the charging contacts on both the station and the mower: dirt and an oxidised layer on the contacts are among the most common causes of charging problems. The contacts can be cleaned with a soft brush or a microfibre cloth. Clean plug connections with a dry cloth only.

If at all possible, place the docking station in a shaded spot. Lithium batteries do not like heat, and a mower and station standing in direct sunlight overheat considerably on a hot summer day. Protection is also provided by a special charging station cover. Some models temporarily switch off some of their sensors when overheating and resume work after cooling down. This is a protective mechanism, not a fault.

A dry, hot summer calls for different mowing

During a drought it is worth raising the cutting height. Longer grass shades the ground, reduces moisture evaporation and withstands heat better. A good rule of thumb is never to cut more than a third of the blade's length at a time. A big advantage of a robot mower is mulching: finely chopped clippings stay in the lawn, retain moisture and return nutrients to the soil.

If lawn growth has almost stopped in the dry weather, you can confidently make the mowing schedule less frequent, as a stressed lawn does not need frequent mowing. It is not worth stopping the mower entirely, though: if the grass grows longer than 9 to 10 centimetres in the meantime, it is already too much for a robot mower and the machine may report an overload error. On hot days it makes sense to schedule mowing for the morning and evening hours, when both the lawn and the battery are cooler.

Disconnect the station from the mains during thunderstorms

Summer thunderstorms are a serious threat to a robot mower's electronics. When a storm is approaching, pull the docking station's power plug out of the socket and also disconnect the low-voltage cables belonging to the station - and on models with satellite navigation, the antenna cable too. If possible, move the mower under cover. We have written about this in more detail in the article Robot mowers and thunderstorms.

Keep the software up to date

Robot mower software updates improve navigation accuracy and battery use, and fix bugs. Most newer models update themselves via the mobile app if automatic updates are enabled and the mower is in its docking station with a sufficient battery charge. It is worth checking the app once a month to make sure the machine has the latest software version.

In summary

Summer maintenance comes down to three simple habits: check the blades and clean the machine once a week, replace the blades together with their screws as a set every month, and adjust the cutting height and schedule to suit the weather. In addition, it is worth having the mower inspected once a year by an authorised service centre, where the components that must not be opened at home are also checked.

Spare blades and maintenance accessories for EGO and STIHL robot mowers can be found in our robotic mower online shop. If you are still choosing the right robot mower for you, feel free to contact our specialists in Tartu at Aardla 25, or via saemeister@saemeister.ee and 7 303 480.