I met my robotic overlord, and I immediately pack-bonded to it.
Let me back up a little.
I am not a gardener. I hate taking care of lawns. I’m the type of person that likes to do a good job, do it well, get the result perfect – and then it should stay that way. I don’t like doing the same thing over and over. It gets dull, quickly.
A lawn takes a lot of work. It runs counter to my pleasure. No matter how well I do the job, in two weeks I have to do it all over again. So my lawn always looks like crap.
So this year I took my government-issued funny money (the CARES stimulus payment, AKA the COVID relief) and plowed it right back into economy. I bought an “automower.” Specifically, I purchased a Husqvarna 115H.
What Is An Automower?
An automower is a Roomba for your lawn. You set a schedule and it takes care of getting the lawn trimmed and keeping itself charged. During operation it makes random passes over its mowing area and covers every square inch… eventually. It comes with a base station where it charges and “sleeps” when it’s not in use.
The mowing area is defined by a “boundary wire” that makes a continuous loop from the base station, around your yard, and back to the base station. (It is possible to have multiple mowing areas.). There is also a “guide wire” that extends from the base station to help the mower come home.
Automowers tend to be “mulching” mowers, meaning they leave their grass clippings in place instead of bagging them up and dumping them somewhere. Since they run so frequently this shouldn’t leave an unsightly mess; each cut should be millimeters in length. Mulching and leaving the grass clippings in place is better for the lawn, as well as making the mower simpler and far more reliable.
They’re convenient, but also environmentally conscious. They’re universally electric, making them quiet, emission-less, and built with a minimum of materials.
My First Thoughts
I purchased direct from Husqvarna. The mower arrived in just a couple of days. (Going through Lowes or Home Depot would have taken a week longer.) The box is an armload but can be managed by a single healthy adult.
Everything you need to set the mower up comes in the box, except housings to keep the power supply and base station dry. More on that in a moment.
The instructions were a bit unclear, but not terrible. There are steps that are in the quick setup guide that aren’t in the full guide, which is annoying, you need to read both.
There are diagrams, but they’re useless until you know what you’re doing – at which point you don’t need them anymore because the rules are quite logical.
The manual spends some time explaining complicated setups with multiple zones and islands, which may only apply to a minority of buyers, but no time spent on some of the most basic (and critical) steps: picking a spot for a base station and considerations for a guide wire.
Here’s What You Need To Know
- There are two wires to worry about: the boundary wire and the guide wire.
- The boundary wire makes an unbroken loop around your yard and through the base station.
- The loop may not cross itself. (This is stated in the manual, but poorly in my opinion.)
- The guide wire connects to both the base station and the boundary wire with a splice. The mower comes with little splice boxes to accomplish this.
- It can connect anywhere on the boundary loop, so long as the first meter (3 feet) extends straight out from the base.
- The guide wire may bend after the first meter, but should not have corners. The mower has trouble following at corners, and may run off the guide and get lost when it’s at its most tired and starving, which will make you worried and sad. Gentle, freeway-style curves are best.
- To save on wire you may bend the guide wire right back to boundary, after you’ve come out a meter from the base station.
- The quick start mentions that you need to make a loop of wire somewhere in the boundary, but the main booklet does not. Neither guide says why you’re doing it: you need to plan where the guide wire will tie into the boundary and leave some slack there. There’s no indication regarding how long to make the loop – a finger’s length is enough. You’ll splice the guide wire into the boundary wire using one of the included splicing boxes.
- The instructions say this, but it’s not clear enough: the boundary wire should not come near the left side of the base station.
- “Left” is your left as you’re facing the front of the base station.
- The boundary wire should run away from the base station at a minimum 45° angle from the left side of the base station, and go out for at least a meter or two. If it’s too close to the base station you’ll get a calibration warning.
- Since most of the important work takes place behind the base station, it would make more sense to change the point of view and reverse left/right in the instructions.
- It’s not clear how frequently to put stakes down to keep the wire in place, except indicating that you must space them a minimum of 30 inches apart. I took my best guess on frequency, but I’m also lazy so maybe I didn’t use enough. Time will tell.
- Finding a good home for the power-brick was harder than expected, as the instructions tell you that it shouldn’t get wet. (That’s an odd requirement for outdoor hardware.) I wound up screwing it under our deck, inside a plastic tupperware bin to protect it from drips.
Total Set Up Time
From unboxing to the mower’s first run was about three hours of work.
Our yard is basically a square, less than two-tenths of an acre, and it’s all behind the house. We don’t have any complicated edges or ‘islands’ that require runs into the yard. Everything we need the mower to leave alone is in the outside edge.
We chose to lay the wire on the soil and stake it down, rather than trenching and burying it. The mower comes with plenty of stakes and wire; we used a fraction of one spool. If there were complicated sections we could easily have used more, but now we have enough leftover to fix mistakes and broken wires for a while.
Laying the wire on the soil was an easy choice because we have very little grass. Our yard was re-graded this spring and there’s still lots of bare soil. (We skipped hyro-seeding so we could customize the mix ourselves – wildflowers on the edge and lots of clover everywhere else.)
We stopped in the middle of set-up to run out and buy a 30 qt plastic tub, to make an ersatz garage for the base station. I’m not counting that time in the set-up time.
I may make a real “dog house” for it later.
Getting the mower itself running was very easy for me. I’m a technical person, your mileage may vary. You push it into the base station to start charging, set a security PIN to prevent theft, fill in some other information, and push “start.” That’s about it for the year, unless you want to make changes.
The unit is quiet. It’s much quieter than I expected. I expected moderate electric lawnmower noise, but I got nearly-silent operation. It’s “guaranteed” to be 59 decibels or less, but as a layman I have no point of reference for that. Suffice it to say, it’s super quiet.
Here’s What You Need To Know
- There are three small blades that attach to a disc underneath. They have a short lifetime. The manual suggests that they will need to be replaced every 4-7 weeks.
- The mower comes with your first summer’s worth of blades, and replacements are relatively inexpensive. We found a set of 30 online for ~$15.
- They look to be reasonably easy to replace.
- You may schedule the unit to run around the clock – it doesn’t care about day vs night. Consider nocturnal animals before you schedule it for nighttime, though.
- You don’t need to shut it off in the rain, though you might want to unplug it during thunderstorms.
- There’s a phone app that connects over Bluetooth that’s easier to use than bending over the control panel on the mower.
It’s very fun to watch. I immediately started rooting for it to knock down tall sprigs of grass and other vegetation. It’s good to watch it to make sure you set the boundaries properly, leaving enough room for “overage.” It will cross the boundary a little, you can’t make tight margins.
We’ve had it running for less than 24 hours and it’s reached pretty much every point on the lawn.
If the mower crosses a boundary, hits something that activates the bump sensor, or gets confused, it backs up and tries a new direction. That seems to be a simple and effective solution.
Here’s a video of the mower in action this morning:
There is a stand of taller weeds emigrating from a neighbor’s yard, which took over that side of the yard last year. It has already re-sprouted and grown to a foot high since we re-graded the yard a few weeks ago. If we let it go all summer again, it will grow into two-meter-tall woody stalks. The mower has been slowly nibbling it back until the bump sensor activates, and has already cut down nearly all of it – about 2 square meters (6 square feet). We might have to weed the very edge of the fence, but that’s it.
Considerations Before Trying
Autonomous mowers might not be a good mower for some situations:
- You like to make patterns in your lawn, like my boss does. He enjoys making checkerboards like you see on professional baseball diamonds.
- Your lawn is complicated, with lots of islands, special plantings, drop offs, marshy spots, and/or slopes. The boundary wires will be time-consuming to lay out.
- There is particularly uneven ground in the mow-zone, with holes, ruts, divots, and/or surface tree roots. The mower could get stuck and require frequent rescues.
- Boundary wires could be a tripping hazard in a high-traffic lawn and are more likely to be broken by repeated stepping. Burying may be a good solution, but complicates installation.
Despite some frustration with the setup instructions, the first 24 hours have gone swimmingly and I’m very happy. This might be the first time in my adult, home-owning life that I’ve had a neat lawn for more than a week per summer.
Having a real, autonomous, domestic robot makes the future feel like it’s finally arriving.