Just put a robotic lawnmower on the lawn, switch it on and off you go? Without any boundary wire? What sounds temptingly simple is already a reality with some robotic lawnmowers. The whole thing only works under certain conditions. Read here what they are.Before a robotic lawnmower can get started, you usually have to take care of the installation of the boundary wire. This is the prerequisite for the mower to find its way in the garden. The tedious installation, which can also be carried out by laypersons, is a one-time affair before the robotic lawnmower can be put into operation. In the meantime, however, some robotic lawnmower models are available that work without a boundary wire. We’ll tell you what the boundary wire is good for, how robotic lawnmowers work and what conditions a garden has to meet in order to use a robotic lawnmower without a boundary wire.
What is the boundary wire good for?
The cable is fixed in the ground with a hook and, like a virtual fence, assigns the robotic lawnmower a specific enclosure in which to mow and which it should not leave. The mower drives until it reaches a limit: the charging station energizes the boundary wire. Although this is very low, it is sufficient that the robot registers the magnetic field generated thereby and thus receives the command to reverse. The sensors are so powerful that they can recognize the magnetic field even when the boundary wire is ten centimeters deep in the ground.For the correct distance to the lawn edge, the manufacturers usually include templates or spacers made of cardboard, with which you can lay the cable at an exact distance depending on the nature of the lawn edges. In the case of patios, for example, the boundary wire is placed closer to the edge than in beds, since the robotic lawnmower can move a bit onto the terrace to turn. This is not possible with the flower bed. The boundary wire also leads the robotic lawnmower back to the charging station when the battery power is low, which it automatically controls and charges.
Boundary cables also mark obstacles
Within its enclosure, the robotic lawnmower automatically avoids possible obstacles such as toys thanks to its impact sensors and simply turns around. But there are also areas such as trees, garden ponds or flower beds on the lawn, from which the robot should stay away from the start. To exclude areas from the mowing area, you must route the boundary wire to each obstacle, route it around the correct distance (using templates) and – this is very important – go back to the starting point, in the same way, using the same floor hooks. Because two boundary wires lie close together, their magnetic fields cancel each other out and become invisible to the robot. If, on the other hand, the back and forth cables to the obstacle are too far apart, the robotic lawnmower considers them to be boundary cables and turns around in the middle of the lawn.Boundary cables can be laid above ground or buried. Burying is, of course, more complex, but is necessary in many cases, for example, if you want to scarify the lawn or a path goes through the middle of the area.
Search cable for large and winding gardens
A special search cable serves as a guide in very large but also subdivided gardens. The cable connected to the charging station and the boundary wire shows the robotic lawnmower the way to the charging station from a distance, which is also supported by GPS in some models. In angled gardens, the guidewire also serves as an invisible guideline if the robotic lawnmower can only get from the main area to a secondary area through a narrow point. Without the guidewire, the robot would only find this passage to the secondary area by chance. Such constrictions must also be 70 to 80 centimeters wide with the guide cable installed. Many robotic lawnmowers can also be told by programming that they should also take care of a secondary area and should be guided by the guidewire.
Advantages and disadvantages of a boundary wire
Robotic lawnmowers and garden owners have become used to boundary cables. The advantages are apparent:
- The robotic lawnmower knows exactly where to mow – and where not.
- The technology has proven itself and is practical.
- Laypeople can also lay a boundary wire.
- When laying above ground, it’s pretty quick.
However, the disadvantages are obvious:
- The installation is complex, depending on the size and nature of the garden.
- If the lawn is to be redesigned or expanded later, you can lay, lengthen or shorten the cable in a different way – which then means a bit of effort.
- The cable can be damaged by carelessness, the robotic lawnmower can then break out. The underground laying is complex.
How do robotic lawnmowers find their way around without a boundary wire?
Tired of dealing with a boundary wire? Then you quickly flirt with a robotic lawnmower without a boundary wire. Because there are also. You don’t have to tinker with installation plans or pay attention to hidden boundary wires when gardening and designing. Simply charge the robotic lawnmower and off you go.Robotic lawnmowers without boundary wire are rolling sensor platforms that continuously examine their surroundings independently like a giant insect and also process pre-programmed processes. This is what robotic lawnmowers with boundary wire do, but the devices without boundary wire are fully equipped compared to conventional models. They even recognize whether they are currently on the lawn or a paved area – or on the mowed lawn. As soon as the lawn is over, the mower turns over. This is made possible by a combination of sensitive touch sensors and other sensors that continuously scan the surface.
Robotic lawnmowers without boundary wire: what should the garden be like?
What sounds good at first has a catch: robotic lawnmowers without boundary wire cannot be found in every garden. Real fences or walls are necessary as a limitation: As long as the garden is simply knitted and the lawn is clearly delimited or framed by wide paths, hedges or walls, the robots mow reliably and stay on the lawn. If the lawn borders a bed with low shrubs – which are mostly planted on the edge – the robotic lawnmower can sometimes overthrow the strings without a boundary wire, also think the bed is a lawn and mow the flowers. In this case, you would have to limit the lawn area with obstacles.In addition to paved areas with a width of more than 25 centimeters, a high lawn edge is recognized as a boundary – if, according to the manufacturer, this is higher than nine centimeters. These do not necessarily have to be garden walls or hedges, wire arches of the appropriate height are sufficient, which are placed at critical points as watchdogs. Abysses such as steps are also recognized if they lie behind an area that is at least ten centimeters wide and clearly grass-free, such as those made from wide paving stones. Gravel or bark mulch is not always reliably recognized as grass-free by current robotic lawnmowers without a boundary wire, ponds need tall plants, arches or a paving area in front.
Which robotic lawnmowers are there without boundary wire?
The market is currently very manageable. There are models from the “Wiper” of the Italian company Zucchetti and the “Ambrogio”. They are distributed by the Austrian company ZZ Robotics. Both are charged like a cell phone using a charging cable as soon as the battery is empty. They lack orientation to the charging station using the boundary wire.The “Ambrogio L60 Deluxe Plus” for a good 1,600 dollars mows up to 400 square meters and the “Ambrogio L60 Deluxe” for around 1,100 dollars a good 200 square meters. Both models differ in their battery performance. The cut surface of both models is very generous at 25 centimeters, gradients of 50 percent should not be a problem. The “Wiper Blitz 2.0 Model 2019” for a good 1,200 dollars creates 200 square meters, the “Wiper Blitz 2.0 Plus” for about 1,300 dollars and the “Wiper W-BX4 robotic lawnmower Blitz X4” a good 400 square meters.
The company iRobot – known for vacuum robots – is also involved in the development of a robotic lawnmower without boundary wire and has announced with the “Terra® t7” a robotic lawnmower without boundary wire that uses a completely different concept. The highlight of the robotic lawn mower is that it should orient itself with an antenna in the radio network that was specially built for it and explore its surroundings with smart mapping technology. The radio network covers the entire mowing area and is generated by so-called beacons – radio beacons that stand on the edge of the lawn and provide the robotic lawnmower with information via a wireless communication system and also give the instructions via the app.