Robot lawn mowers

[Dave2002]

I have seen a robot vacuum cleaner at work. It’s an endearing little thing to watch as it goes round, bumping into a chair leg, adjusting itself and carries bravely on. It goes back to its charging point and set itself to be recharged, and does a few more clever things. This apparently has been developed to pick up invisible dust on a wooden floor and as such, has a dust collection box the size of a match box. All for this for mere £600.

Guessing from this, a robot lawn mower will be a good thing if you want to keep your lawn immaculate and in need of something that can give your job a finishing touch.

I can confirm that the robot vacuum cleaners do go back to their "little" base station. Actually they are a bit stupid. They don't look where they are going, so they will go past obvious dirt, and keep bumping around until they either pick the dirt up or the batteries run out. However, they are still reasonably effective, and dont' require much attention. Future versions hopefully will have vision and AI - though I don't see why those features haven't been built in now - other than to maximise future profits from the manufacturing companies.

Here is a "cheapie" lawn mower version - which "only" does 400 square metres - though I don't see what the limit is.

https://www.flymo.com/uk/products/ro...00r/967204003/ It is recommended as being useful enough and at a cheap enough price point.

As I hinted before, if it takes an hour to charge, and an hour to do its thing, then it could get 12 cycles per day, so on each shift it has to do 33.33 square metres to get a 400 square metre area into shape in 24 hours, with repeats in the next day. It's hard to know exactly what the limiting factors are. Why can't it do twice that area, but cover each patch once every 2 days instead of every day? It's going to depend on how fast the grass grows, and presumably the grass does need to be cut hard before these robots get to work, otherwise they'd be swamped.

[Serial_Apologist]

I can confirm that the robot vacuum cleaners do go back to their "little" base station. Actually they are a bit stupid. They don't look where they are going, so they will go past obvious dirt, and keep bumping around until they either pick the dirt up or the batteries run out. However, they are still reasonably effective, and dont' require much attention. Future versions hopefully will have vision and AI - though I don't see why those features haven't been built in now - other than to maximise future profits from the manufacturing companies.

Here is a "cheapie" lawn mower version - which "only" does 400 square metres - though I don't see what the limit is.

https://www.flymo.com/uk/products/ro...00r/967204003/ It is recommended as being useful enough and at a cheap enough price point.

As I hinted before, if it takes an hour to charge, and an hour to do its thing, then it could get 12 cycles per day, so on each shift it has to do 33.33 square metres to get a 400 square metre area into shape in 24 hours, with repeats in the next day. It's hard to know exactly what the limiting factors are. Why can't it do twice that area, but cover each patch once every 2 days instead of every day? It's going to depend on how fast the grass grows, and presumably the grass does need to be cut hard before these robots get to work, otherwise they'd be swamped.

Also, is height of cut adjustable?

[oddoneout]

I have seen a robot vacuum cleaner at work. It’s an endearing little thing to watch as it goes round, bumping into a chair leg, adjusting itself and carries bravely on. It goes back to its charging point and set itself to be recharged, and does a few more clever things. This apparently has been developed to pick up invisible dust on a wooden floor and as such, has a dust collection box the size of a match box. All for this for mere £600.

Guessing from this, a robot lawn mower will be a good thing if you want to keep your lawn immaculate and in need of something that can give your job a finishing touch.

With a bit of thought you could come up with extras to keep cats amused indoors and dogs exercised outdoors for those who insist on having pets but can't be ar..sorry, bothered to meet the basic needs for entertainment and exercise.

[Dave2002]

Also, is height of cut adjustable?

Some of them - such as the rather more expensive Husqvarna or Robomow models, do have adjustable cutting height, which can be monitored and set remotely.

[Anastasius]

Some of them - such as the rather more expensive Husqvarna or Robomow models, do have adjustable cutting height, which can be monitored and set remotely.

Ah, but can they do stripes ?

[Dave2002]

Ah, but can they do stripes ?

Or checker board patterns - as at Eastbourne - perhaps! Don't think so - is that important?

[Anastasius]

Or checker board patterns - as at Eastbourne - perhaps! Don't think so - is that important?

It was meant tongue-in-cheek

[Dave2002]

They can work in the rain.
They can work at night.
They can cut through their own boundary wires - and stop dead having done so.
They can get stuck while trying to get back into their charging stations.
They can bump/bound into/over their charging stations when not intending to go there.
They are very quiet compared with ride-on mowers, or even hand steered petrol mowers.

Update on the robot vacuum cleaners:
They can send a message (email) when finished, or in case of errors.
They can produce a map - though not very accurate - of the areas swept.

[Mal]

Just don't mow the lawn and tell the council and neighbours you're rewilding....

[oddoneout]

Cutting at night doesn't sound very wildlife friendly - if the machine can cut through its boundary wires and mismanage docking then anything live on the grass at night is also at risk? Hedgehogs have enough to cope with without a whirling bladed machine trying to mount them.

[ferneyhoughgeliebte]

Cutting at night doesn't sound very wildlife friendly -

Nor "neighbour-friendly" for that matter!

[Dave2002]

Nor "neighbour-friendly" for that matter!

It’s OK - I’ll turn the volume up really loud - https://youtu.be/ltmwT7AktnA

[Dave2002]

Cutting at night doesn't sound very wildlife friendly - if the machine can cut through its boundary wires and mismanage docking then anything live on the grass at night is also at risk? Hedgehogs have enough to cope with without a whirling bladed machine trying to mount them.

Once installed and glitches ironed out I don’t think the problems with wildlife are significant. Birds seem to like them, and can avoid them. I think the mover might disturb worms under the surface making the lawns attractive to birds, or perhaps it’s just the dislodging of grass and other seeds which attracts the birds.

Environmentally I believe there can be big benefits. Power consumption is low, and saves energy in taking large bags of lawn cuttings to the tip. They are much quieter than conventional petrol driven lawn mowers. The fine cuttings are dropped back onto the lawn and will act as a nutrient source - or at least not deplete nutrients, which is the alternative if cuttings are taken to the dump.

They can, and do, work in the rain. One of the cheapest is the Flymo 1200R - there are others which are cheaper, and some very expensive models with wireless communications and GPS. The 1200R will probably take several days to trim a lawn - based on a 17cm cutting circle - and perhaps 20 traverses per hour of an area 30 metres wide, and maybe 10 active hours per day. The area covered each day might be as much as 1000 sq metres, but this is based on randomised cutting and an assumption that 10 active cutting hours is feasible. Cutting alternates with charging, so the effective number of active hours might only be around 6 per day. Randomised movements might mean that some parts of the cutting area don’t get visited for days. Also, some traverses might simply bend over grass, clover, weeds etc., and not cut them.

Over a period of several days it should be possible to get most of an area of up to 400 sq metres, which is within the specified capability of that particular model, cut. Cutting height can be left fairly high, so that clover and other flowers (daisies, buttercups) “weeds” are still available for bees and other wild life, for a time.

There is no real point in having these for small “postage stamp ” lawns, which can be cut quite quickly with a small mower, but for larger areas there seem to be significant benefits. Wildlife does not have to suffer, and annoyance to neighbours who might get upset if a hay field appears next door [am I bovvered?], is reduced.

[gradus]

Can they find their way from one area of grass to another within the garden, say along paths? Are odd shaped lawns ok ie those formed between between circular and kidney shaped beds etc?

[Dave2002]

Can they find their way from one area of grass to another within the garden, say along paths? Are odd shaped lawns ok ie those formed between between circular and kidney shaped beds etc?

OK - we have one. At first I put the boundary wire round the edges to stop the thing going over the paths, then once we got it going I realised that it’s quite happy trundling over the paths - though these things don’t like gravel it seems. I still put the wire round some plants/bushes/beds I didn’t want it to crash or fall into. I also put wire round large obstacles such as the large mill stone we have. However after a while I decided to reuse that wire, so I rerouted it and it just bumps into the stone, then turns round. That saves wire, and doesn’t seem to be a problem.

The 1200R is supposed to have a limit on the length of boundary wire. It is possible to have secondary areas, but the mowers won’t deal with them automatically. The unit would have to be picked up and allowed to roam until its battery runs out - it would not get back to base to recharge automatically with that layout. For that reason it would be sensible to only have small areas of secondary “islands”, to minimise the manual intervention.

Our layout is probably on the limits of the boundary wire suggested max length, but I have a cunning plan for the relatively small patch at the back. I intend to lay more wire from the base round to the back - but this would give a boundary wire longer than recommended. Then I’ll put switches in to send the electrical signal round the back area, but I would treat that as a separate island for manual operation. I don’t actually see why it shouldn’t also be possible to have switched guide wires, so that each area (zone) could be used to run the mower unit automatically, though in our case that might cause problems because of obstacles, such as a gate.

If there are lawn patches on different levels, for example with steps between them, it might be necessary to use manual intervention, though wiring may not be a problem. Some garden redesign with ramps might be necessary for fully automatic mowing in a multi-level garden.

One issue with paths is what to do with the wires. If there are borders or grassy bits, then the wires may go there, but if the paths are stone or concrete it might be necessary to create channels (angle grinders or hammer and chisel) to put the wires in. Gravel would be easier re the wires, but it’s not recommended to let these mowers run over gravel.

If areas are very narrow, I’ve read reports of other mowers going into them, but then the random algorithm means that they can get “stucK” repeatedly trying to find the way out. That issue is best avoided by not having such narrow sections, but if it’s unavoidable then a solution would probably be to route the guide wire through the narrow section. That should enable the mower to find its way back to base through the narrow spot. It wouldn’t otherwise affect operations, as the mower doesn’t always use the guide wire to get out onto the wider areas - only for return. Multiple narrow passages might be too much to cope with, though.

If you want more info you could PM me, or we’ll continue here.