Robot Mower Installation Basics

Robot Mowers  · 

Start at the dock, because everything returns to it

The dock is the one part of the install that has to be right, because a mower that cannot land on its charging contacts is a mower that stops working. Site it on level, firm, well-drained ground, ideally on a paving slab or a strip of concrete so it does not settle into soft turf, with a clear straight approach from the lawn and enough room for the machine to swing round in front of it. A dock on a slope lets the mower creep off the contacts; a dock in a hollow sits in water after rain.

The dock runs from a low-voltage adapter plugged into mains power, so the run to an outlet decides the position as much as the lawn does. The adapter belongs indoors or in a weatherproof enclosure, on a socket protected by a residual-current device, with the low-voltage cable protected where it crosses a path. Some makers also want a metre or two of clearance from sprinkler heads and a route that keeps the mower away from parked cars.

Running the boundary loop

The boundary wire leaves the dock, runs around the whole lawn, and comes back to the other terminal. The offset from walls, fences and beds is a compromise: set it tighter and the machine reaches more grass but scrapes the shell and rides over edges, set it wider and it never touches anything but leaves a band of grass for the trimmer. Corners should be rounded rather than square, because a machine following the signal through a sharp turn cuts the corner.

Keep the loop away from things that disturb the signal or damage the wire: metal lawn edging, reinforcing mesh, buried cable and irrigation solenoid boxes. Where the wire must cross a path, run it through an expansion joint or a buried sleeve so the mower passes over it without a bump. The route should avoid anywhere you will dig later, since a vegetable bed, a new planting hole or a fence post hole is where a loop gets cut.

Islands, excluded areas and separated zones

An island is created by running the wire around an obstacle, such as a tree, a flower bed, a pond or a washing line base, and bringing it back alongside the run that leads to it. The mower reads the enclosed patch as being outside the lawn and circles it. The two legs of that loop must be kept a hand’s width apart; laid side by side they cancel the signal and leave a gap the machine can drive straight through.

Anything larger than a shrub, or anything that must never be mown, is better handled by exclusion than by hope. A pond, a steep bank, a gravel border or the strip beside a road can be kept out of the mowing area by routing the loop around them, and app-managed machines can be given a drawn keep-out zone instead. A second lawn separated by paving becomes a separate zone reached through a wire corridor or, if that is impractical, by carrying the machine across.

Guide wires and narrow passages

A guide wire branches off the dock and runs out into the lawn. The mower follows it to leave the dock in the direction you choose and follows it home instead of searching along the perimeter, which matters most where the lawn is long, L-shaped, split by a narrow passage or fitted with a dock tucked round a corner.

In a narrow gap between a hedge and a wall, the guide wire sets the line the machine takes, so the passage has to be wide enough for the mower to travel it in both directions without clipping either side. Route the guide wire down the centre of the passage, keep its bends gentler than the machine’s turning circle, and bring it out into open ground before it meets the boundary. Where the lawn has two distinct areas, one guide wire per area is usually what stops the mower from spending its day trying to find its way back to the dock.

Staples, burial depth and sealed splices

Peg the wire down with landscaping staples at close intervals on straight runs and closer together round corners, dips and changes of surface, pressing each staple flush so the mower’s wheels do not catch it. Leave a little slack between staples: wire strung tight across a root or a high point is the wire that snaps when the ground moves, while wire laid with gentle slack rides out frost heave and settling turf. Bury the run only where it must survive foot traffic, an edging tool or mulch, and keep the buried sections shallow enough to find again.

Splices are the weak point of any loop. Use a gel-filled or heat-shrink sealed connector rather than a twist and tape, place the joint where water does not pool, and note its position so a future fault can be found quickly. Every splice adds resistance, and a corroded one shows up later as a machine that stops in the same spot or refuses to dock. Walk the loop with the signal indicator before you cover anything up, so a mistake costs minutes rather than a day.

The RTK base station and the mapping run

A wireless machine trades wire for a reference station. The base must see a wide, unobstructed sky, so it is mounted high and clear of hedges, tree crowns and rooflines, on a bracket that will not move, because its own position is the fixed point every correction is measured against. Corrections travel back to the mower over a radio link or the mobile network, and a poor fix shows up as a machine that wanders, stops at phantom boundaries or misses strips.

The mapping run is the last step for any machine that builds a map rather than following a signal. Drive or walk the machine round the lawn, teach the app the outer boundary, the zones, the channels between them and the areas to avoid, then send it to the dock and let it run a full mowing pass. Expect to adjust a zone edge, a channel width or a keep-out area after that first pass; the map is a draft until the machine has proved it can cover the lawn and find its way home.

FAQ

How deep should the boundary wire be buried?

Most installs do not bury it at all: the wire is pressed into the thatch at the soil surface with staples and the turf knits over it. Bury it only where it has to survive an edging tool, foot traffic or mulch, and keep those sections shallow and easy to locate.

How far should the boundary wire stay from a wall or a flower bed?

The offset follows from the mower’s body width and the wire’s signal field, not from a fixed rule. Set it tight and the machine scrapes and bumps; set it wide and you leave a strip for the trimmer. Beds are usually best treated as islands so the mower circles them rather than driving into the plants.

Do I need a guide wire if I already have a boundary loop?

Not always, but it earns its place on long, narrow or L-shaped lawns and on any site where the dock is hidden round a corner. The guide wire tells the mower which way to leave and gives it a direct line home, which cuts down the time it spends hunting along the perimeter.

Can a cut boundary wire be repaired with a splice?

Yes. Use a gel-filled or heat-shrink sealed connector, keep the joint above the level where water pools, and note where it is. A single repair is harmless; several corroded splices add resistance and can confuse the loop signal, which is why the joint quality matters more than the repair count.

Where should an RTK base station be mounted?

Where it has a clear, wide view of the sky and cannot move: high enough to clear hedges and rooflines, fixed to a rigid bracket, with power or a charged battery available. Under a tree canopy or tight against a wall, the position fix degrades and the mower’s boundary becomes unreliable.