LUBA: the lawn wears into a bare circle in front of the charging station

What owners report

• A LUBA 2 owner from 2023 says the biggest trouble in the first season was grass torn up along some edges and in front of the charging station¹.
• A LUBA 3 AWD owner says theirs does fine on thick, established turf for most of the area, but will destroy any lawn in front of the charging station, even thick turf⁶.
• A bare patch. One LUBA 2 owner has a 4x4 section in front of the charger that is bare dirt. They had put the station in a mulch bed to protect the grass, and then kept having to fix the mulch⁵. Another owner's LUBA 2 got stuck, bottomed out, in divots it had dug over two years of docking⁵.
• A circle. A four-year owner writes that, despite doing many of the same things as the thread's author, the mower still made a rut in a circle in front of the charger. The grass was still alive, but grass and soil had pressed down into a circle². An owner in Scotland says it tears a doughnut through their thick grass when it leaves the station⁵. Another owner asks why the mower digs a round well in front of the station by always turning around as a tank at the exact same spot⁴.
• Rubbed raw. One owner says the omni front wheels were getting caked with dirt and grass roots, and that the rubbed raw areas were getting deeper⁴.
• A fescue lawn. An owner whose lawn is elite tall fescue varieties says the repeated damage from tank turns in front of the station takes a toll³.
• Not everyone has it. One owner mows every other day, and the mower always turns in the same spot, but their thick, healthy grass does not get dug⁵. Another says they have no damage⁵.

Why owners think it happens

• The same spot, every time. An owner says the mower turns reasonably accurately in the exact same spot each time it leaves the charger. They watched the back wheels do the first damage, and once ruts formed the omni wheels snag and tear as it turns in the same ruts⁵. Another, whose lawn needs about five recharges a day, says that once the ground is moist it is just grinding through the soil⁵.
• Thin grass and loose or wet ground. One owner says thick, healthy grass does not dig, but thin grass over loose ground will⁵. Another says that very sandy soil, or loose topsoil over clay that stays gooey when wet, is a poor match for omni wheels⁵.
• Cutting height and older wheels. A three-year owner says a lower cut means more friction and more bald spots, and that first-generation LUBA wheels touch more of the lawn². That is one owner's reading.
• Software or hardware. Owners disagree. One blames the omni wheels, and another says the hardware only tears the grass a bit while the software lets it dig a circular ditch⁵.
• Updates. An owner who laid concrete slabs where the mower used to turn says that after a later firmware or app update it turned beside the slabs and tore up grass instead⁵.

What Mammotion says

Mammotion staff accounts have answered owners in these threads on the pad, the station's surroundings and the front wheels:

• A hard pad. To a LUBA 3 5000H owner who asked about pouring concrete where the mower turns in front of the station, a staff account wrote on 20 September that pouring a concrete pad there is a workable solution. It added that some users have placed a hard mat at the spot where LUBA turns, which can minimise the impact on the lawn⁷.
• Where the station sits. To a LUBA 3 owner with a dug-up area, a staff account wrote on 19 September to avoid placing the station on muddy or wet grass, and recommended a concrete surface or turf in that area. It also advised setting the damaged area as a no-go zone, and fertilising and overseeding⁸.
• Returning to a task. To a LUBA 2 owner whose mower turned in one spot when returning to its task from the station, a staff account asked whether multi-point turning was set, and suggested temporarily using the edge-following mode for recharging, to reduce wear on the lawn in a single spot⁹.
• Front wheel rollers. On 22 October a staff account told a LUBA 3 owner whose front wheels were clogged with mud that the small rollers on the omni wheels need to rotate freely. If debris stops them, it wrote, the wheels may rub against the ground instead of rolling, which could be one reason for lawn wear. It recommended avoiding wet lawns, and, if the mower has to run, reducing the mowing speed, adjusting the mowing angle and raising the cutting height¹⁰.
• Docking. In reply to an owner whose mower was wedged at its dock, a staff account wrote that the mower typically rotates in place to search for the station's infrared signal when it is about 1.5 m away. It suggested resetting the station's position in the app³. Mammotion's return-to-charge guide says to install the station on firm, level ground with at least 1 m (3.3 ft) of clear space in front⁴. Both are about docking, not about the lawn.

For docking errors and station problems, see charging and docking fixes. For wear at turns elsewhere on the lawn, see turns tear up the lawn.

What owners put there

• Pavers, tiles or concrete. A four-year owner built a paver pad off the grass where the mower turns, and says it works much better². Another put cement bricks level in the ground where the bare trenches were⁴. Two owners laid outdoor tiles, one of them cheap plastic ones, and say they work⁵. The Scotland owner's slabs stopped helping after a later firmware or app update, when the mower began turning beside them⁵. Another owner built a two-foot paver border for the mower to turn on, and says it worked until later updates; with obstacle avoidance on, the mower would no longer use the pavers, so they turned avoidance off¹². An owner on newly laid sod says to leave several feet of concrete in front of the station for the turn¹¹.
• Mats. An owner whose LUBA 3 does the zero turn it needs to back into the dock uses 24 inch rubber mats from a hardware store, set outside the mowing area so it does not turn on the grass to dock¹⁰. Another laid a thin roll of mat with holes for grass to grow through, pegged down at the corners, and says the mower never caught on its edges⁷. A third owner has laid hard plastic sheets at every turn point on their channels, because the new turns had worn holes the mower bottomed out in⁹. One owner weed-whacked the grass bare in front of their LUBA garage, laid a rubber drainage mat and seeded over it. A couple of years later there is no problem, and the turn shows only if you stand over it⁴. Another buys rubber mats with holes that grass can grow through, and plans to remove them once the grass is established⁵.
• Artificial turf, and moving the station. One owner set the station about 1.5 m back from the lawn edge and laid artificial turf on the way in. It still damages the lawn slightly at times, but only a little⁵.
• The lawn itself. A three-year owner raised the cutting height to 2.4 and moved Bermuda grass into the bald spot². Another puts a no-go zone around weak patches, trims them by hand, and feeds and waters them⁵.

What is not known

No source says which firmware or app version changes where the mower turns, or how often is too often. Most owners do not name their model. Whether a hard pad lasts when a firmware or app update moves the turn is reported once, and not resolved.