Students’ Leaf Blower Suppressor To Hit Retail

Electric leaf blowers are already far quieter than their gas-powered peers, but they still aren’t the kind of thing you’d like to hear first-thing on a Saturday morning. Looking to improve on the situation, a group of students from Johns Hopkins University have successfully designed a 3D printed add-on that manages to significantly reduce the noise generated by a modern electric leaf blower without compromising the amount of air it’s able to move. The device has proven to be so successful in tests that Stanley Black & Decker is looking to put a commercial version of the device on store shelves within the next two years.

The team says the first part of the problem was identifying where the noise was actually coming from. After taking an example leaf blower apart and studying all of its moving components, they determined that most of the noise produced wasn’t mechanical at all — what you’re actually hearing is the complex cacophony of high-speed air rushing out of the nozzle. With this knowledge in hand, they isolated the frequencies which were the harshest to the human ear and focused on canceling them out.

Let’s try spinning the air, that’s a good trick.

We’re assuming the pending commercial venture with Stanley has prevented them from releasing too much technical information about the gadget. But from what was published on the university’s news site Hub and the video below, it’s explained that a portion of the air is redirected into channels printed into the device, which slows it down before dumping it back into the stream.

To be clear, this doesn’t eliminate the noise completely. In a side-by-side comparison, the suppressed blower is still fairly loud. But with the shriller tones removed from the mix, it’s at least a less annoying noise.

As designed, the printed suppressor is meant to attach to an otherwise unmodified blower. But we’re willing to bet that Stanley instead plans on implementing the technology directly into the nozzles of their future blowers. That way, rather than selling you a simple plastic add-on, they can get you on the hook for a whole new blower.

That is, unless somebody out there decides to come up with their own DIY version. We’ll keep an eye on the tip line should anyone want to share with the class.

81 thoughts on “Students’ Leaf Blower Suppressor To Hit Retail

      1. Not really, some of the electric ones will be far more powerful than the usually two stroke smoke machines…

        The power density of the energy source will limit the runtime with electric in comparison. But unless you are a professional leaf blower the stored energy of the usual power tool lithium battery is probably sufficient for your needs, and if not even carrying a second battery its likely to be a lighter tool. Yes some electric are quite weak in comparison, but equally they can go harder and there are reasons you may want both, not everyone needs the can lift and hurl a pebble through a pane of glass, just a bit of force to push those leaves off the paved area.

          1. Well aware that it’s not a joke.

            Leaf blower airplanes are old. The electric ones were not first.

            You can also make a hovercraft out of a leaf blower, some cardboard, duct tape. Don’t forget to fill with eels.

        1. Practically speaking, electric leaf blowers are pretty terrible at sustained duty, battery heat is the limiting factor. To run it continuously you need several batteries and cycle through run – cool – charge every couple of minutes. I have a *nice* electric leaf blower and definitely would not be satisfied with it if I was like a golf course landscaper or whoever it it that hates leaves

          1. I don’t understand why people seem to think electric tools and battery tools are perfectly synonymous.

            I understand not being able to drag a cord around a golf course, but corded electric tools are cheaper and run for ages at very high power and torque the whole time. When you want sustained high power from an electric tool, like with this or with grinders, I would default to a cord until finding out that the use-case doesn’t allow for it. Whereas, the batteries are ideal for things like drills/impacts and some kinds of saw especially ones you only use briefly.

    1. first line of the article:
      “Electric leaf blowers are already far quieter than their gas-powered peers”

      first comment in the comment section:
      “They’re using an electric leafblower in the video, which already gets rid of most of the noise by ditching the gas engine.”

        1. Use cookies to lock it for 30 minutes after it’s read, use a reading comprehension quiz for a CAPTCHA, and give readers a sucker punch button that causes a 3-month ban to the deserving.

      1. I suspect that since it’s being commercialized, you won’t, at least not from these inventors. Functional clones may appear later, hopefully in a user modifiable format like OpenSCAD to allow customization for various blower brands.

      2. I mocked it up as best as I could with made-up numbers for diameter (~3.1″) and taper angle (2.0deg) since I am to lazy to go out to my shed and get my electric leaf blower. At 0:55 in the video there is a close-up of the end of one of the mufflers, and it looks like it is made of multiple pieces, with some black material lining the outer shell. I am going to guess that might be something acoustically absorbent, but inexpensive and easy to get, like a sheet of neoprene with an adhesive back. That way, you can stick it inside of the outer shell and then insert the center with the helix. That is the kind of material I would expect in a senior design project when you are iterating through designs and need stuff cheap and quick.

        So, I designed it that way for the one I did. https://imgur.com/a/Qr0vOhb

        I’ll probably get my leaf blower and update the model so it fits on my leaf blower, and if it works well, I’ll post it to Printables and Thingiverse.

    1. Broom also doesn’t blow.

      My leafblower mostly gets used to blow leaves and such off of my front yard, which is a gravel hardscape (I’m in Arizona, we don’t do grass).

      Broom doesn’t really work on gravel, neither does rake – but blower blows the junk away, while leaving the gravel.

      I also use it to blow the super-sticky clay dust we get around here when it gets windy off the driveway – broom just gets it stuck on the concrete (as well as itself). Blower sends it to places I don’t mind it being, such as the aforementioned gravel.

      Brooms are great for the jobs they are great for – they are much less great for the jobs they suck at. It’s all about the right tool for the right situation.

  1. I wonder if you can apply this to vacuum cleaners. I’ve a cordless where most of the noise seems to be from the air coming out the other side through the filters, and it is quite shrill; something to convert that to a less screechy tone would be great.

    1. I read a thing about product design a while ago that talked about this.
      Apparently in product testing, the vacuum cleaner that was quieter scored lower on customer acceptance as the perception was that less noise = less cleaning power, even though the opposite was actually true in the tests.

      People expect a powerful appliance makes more noise, even when it’s not true.

      1. Few other products advertise the amount of current draw as a feature!

        Aside from the “brilliant” stupidity of lightbulb marketing…

        (Amazed lumens never caught on, the number is bigger than the wattage!)

      1. Anything that can be used as a suppressor (for a gun) can get you a visit from the assholes in cheap suits.

        It’s already happened for oil filters…Which make shitty suppressors as they obstruct the sights.
        This is covered by the ‘never talk to cops’ rule.

    1. Agreed. Our neighbor’s yard guy has the loudest one I have ever heard. Thirdhand piece of junk that runs out of sheer spite and roars like a banshee. I have to control myself every other week at 7 am from pulling that thing out of his hands and beating it to pieces with a hammer. It is always on a day I get to sleep till 7 grrrr. The electric ones are only marginally better if you don’t mind the high squeal of an inflator pump blower lol. Most of this stuff can be done with the mower anyway using it to blow crap off and raking later to tidy and use as bedding. But who cares with all of the modified exhausts, biker gnat swarms and rev limiting, and backfiring ebay modchip dodges etc trying to plow from light to light. It scares the dog, the cat, the horses hate the backfiring, and the deer just run in terror. I hate it for my animal friends.

      1. Why do these asshats feel the need to do this early in the morning? What about it is a morning job?

        Make all the noise you want around lunchtime or whatever but why the hell get up early just to thrash a tiny angry 2-stroke around?

    1. Also doesn’t work in a lot of situations. Try using a rake on a hardscape, all you’ll accomplish is moving all your gravel to the other side of the yard.

      And if you have anything over half an acre? It takes long enough that the leaves build up faster than you can rake.

      This is HackADay, I thought we were all about the right tool for the right job, even/especially if we have to make it ourselves.

      Rakes are great for specific situations, like keeping Silent Bob at bay.

    1. I assume it’s because the US has a lot of strict laws about lawn care, as a means of class conflict. Occasionally you here about a sickly old person who becomes homeless because they were too weak to mow the lawn and too poor to pay someone to do so.

        1. The law states that you must abide by a contract that you agreed to abide. Using that law people bind themselves to actions and must pay the prescribed rice if they do not.

          It always amazes me to hear complaints from people who have signed home owners association contracts which are being enforced on them. What EXACTLY they thought would happen remains a mystery to me.

          “Rules for thee and not for me” I suppose.

    2. There’s still a big push to maintain a 1950s-style idealistic perfect yard with a little white picket fence and, of course, no leaves. As bob mentioned, sometimes it’s enforced by neighborhood boards. Few have the time, desire or physical ability to keep up the facade, though, so commercial lawn care with industrial machinery is a big business.

      1. So the leaf blower blows leaves, but where is the step that eradicates the leaves? Or you just blow them off your property so it’s no longer your problem?

        1. In larger communities with neighborhood-wide lawn care (it’s part of neighborhood fees), they might blow them into giant piles and a truck with a very large vacuum cleaner sucks them up. Then they’re removed to a biomass generator, mulching facility or landfill. For individuals and small lawn service companies, it’s exactly what you’re picturing.

          1. In some places you blow them into a pile and then rake the piles into a bag for yard waste pickup. In others you blow them into a pile in the street and the aforementioned big vacuum truck comes by to suck up the piles from each house, like trash pickup.

          2. Forgot the step after the mulching facility, they go collect their free mulch and return the leaves to the landscape where the leaves could have been blown to start with. 🤔🙄🤷

      2. I hate my Home Owners Association so much – I bought a house in a new development last year, and the board is still run by the builder. They want everything supernaturally neat to help them sell houses, so my HOA fees are paying for them to send “inspectors” out twice a month, and if there is so much as a single weed anywhere, you get a sternly worded letter warning you of fines if they aren’t cleared immediately.

        I just received one yesterday – the inspector came by within two weeks of my landscaper, who left the place impeccable. Weeds do grow fast here, but not enough to become problematic in under 14 days.

        I’m medically disabled, chronically ill, and can barely leave the house; I’m not going to be going weed hunting with a microscope every couple days, just to help them sell houses. I already paid $400,000 for the house, and am paying them HOA fees every quarter, which seem to go almost entirely towards sending agents to harass us actual home owners, rather than providing any actual benefit.

        The actual people living here are great, too, but somehow, because the builder decided to expand on the development, the HOA continues to be run by them, over a year after I moved in. The management company they hired with our money was seemingly given the sole task of harassing us.

        I already told them that they should step carefully, given that the HOA board will eventually be run by us homeowners, and the moment it is, I will make it a point to get on the board. As it stands, my first order of business will be to fire the management agency, and hire an actually competent one capable of representing our interests.

        If they don’t want that to happen, they better clean up their act – the last letter I received from them gave me a 10 day window from the date on the letter to contest their claim, and it didn’t even arrive in my mailbox until eight days into that window, and it was postmarked six days into it.

        Of course, I’ll make sure we get a different company regardless, as I am not the forgiving type in such situations, and their leadership is seemingly dumb enough to not care about alienating home owners who will be running the HOA for the next 20 years to please the builder, who will be gone within the year.

        TL;DR: An Home Owners Association not run by the home owners is the sort of thing that makes you think maybe humanity was a mistake.

        1. Nobodies fault but your own.
          You bought a HOA house.
          Suck it up.
          It will get worse, once the local busybodies get on the board.

          The people on the other side of my road are in a HOA.
          They live in daily hate of our freedom, big lots and projects. Even those projects not involving pulsejets.
          County ignores them, assholes cried wolf too many times.

          1. The majority of new homes are built as parts of HOAs, it’s not the buyer’s fault but lack of government legislation that prevents abuse. Many HOAs function as a de facto local government, without the oversight of governments.

          2. Nobody forces anybody to buy a HOA home Andy.

            Also: Most new construction is hot garbage.

            Consider the tension slab. That’s a ‘crete slab with a post tensioned cable running back and forth. That cable will predictably fail from corrosion, in about 50 years. Then the slab will fail. Then the house is unfixable trash.

            Houses on slabs now have a design life of 50 years+-.
            We’re Japan now. Houses are disposable, like Bic lighters and German cars.
            First big batch of slab failures is about 20 years off.

            Don’t be smug knowing they don’t do slabs in your area.
            Your new house’s design life is still about 50 years.

    3. Thanks for all the replies, that’s very enlightening.

      But seriously, neighbourhood boards who mandate how your lawn looks and provide neighbourhood wide lawn care sounds incredibly socialist! Here in the UK you can let your lawn become a wilderness and have rats nesting in it, and it’s your property, no one else’s business.

      1. The US is not perfectly homogenous. Not all cities have this insipid requirement, and not all developments do, either. Where I live, I don’t have to take care of my property at all, but I do because I enjoy it. Of couse, I don’t use leaf blowers because they’re man’s most asinine invention: a tool that does less than half the job of a good rake, mower, or broom, and accomplishes the lofty goal of destroying the operator’s ears. And I have 8 acres to manage.

        1. Indeed, who can be a pernickety and stupid as any US neighbourhood I’d think. Though perhaps will take much longer to notice you ignoring them…

          Still it does seem bonkers to me that is a thing in the US at all, and surely it can’t be in drought prone regions? As that would be even weirder, lawns tend to be thirsty as far as I know. The last thing I’d want is a vast patch of grass mown tiny all the time, its great if you have the space to let your kids or something really have a safe playspace to have a larger patch of lawn, but otherwise you just need enough hopefully under a shade providing tree or two to sit out and enjoy the flowers, shrub, taller grasses and the butterfly, bee, and birds going loopy for a space that actually has some life for them left in it…

      2. Not remotely socialist – it’s authoritarian in the extreme. Home Owners Associations are run by a board of home owners, which ostensibly represents the interests of the community.

        But being a board member takes time and effort most people can’t afford to dedicate to it, so, in practice, boards are usually run by a bunch of misanthropic retired people with no friends, and nothing better to do with their time than to make everyone else’s lives as unpleasant as their own.

        Under socialism, everyone is intended to be equal. An HOA is a vicious form of gerontocracy, where the most miserable elders do their best to make everyone join them in their misery.

        1. Marxism is authoritarian at it’s core. No fixing it. Economy has no way to self organize.
          Karl really was a moronic anti-Semite, just like most of his followers.

          Non Marxist socialism is a thing (the term predates Marxism), but beware Marxists trying to get their idiocies thin edge in. They are more confused then rednecks. I blame their ‘teachers’.

          HOAs just suck. But everybody in a HOA volunteered for the suck. Sucks to be them.

          1. I’m not familiar with Marxism but if it’s about economic controls, that doesn’t mean the same controls have to apply to other parts of life such as individual rights. Therefore Marxism doesn’t have to be “authoritarian” like a country that doesn’t respect human rights.

            I heard that the original writings of Marx meant to give power to the workers, because in his time the factory owners were the oppressors of their employees, paying little for hazardous working conditions. Even children in the United States worked with knives and dangerous industrial sewing machines!

          2. Andy: Theory is BS.

            Without markets, you have to have a command economy. Without private ownership of ‘means of production’ you cannot have markets.

            That means someone is doing the ‘commanding’. That power always corrupts.
            Can’t fix it, put the remaining followers in a zoo.

      3. UK…Lawn?

        I don’t think that word means what you think it does. Nearest thing you have is a ‘village green’.

        Also: UK councils are the HOA from hell. At least to vote for an HOA board, you have to be a property owner.
        Councils are voted in by people with no skin in the game. They love to raise taxes and spend it on work shy voters. ‘Shameless’ is a documentary.

        1. It’s often a repeating circle too. The only people with enough time to “serve” in local government (parish councils can be even worse) are more than often those with lots of spare time. Which means either retired or not working by choice. So you get NIMBY’s or communists.

  2. Leaves on the sidewalk can pose a safety hazard. Leaf blowers help herd the leaves to a central area for mulching or disposal. I use a vacuum-shrediing device to pick up the leaves. And I only do these activities closer to noon.

  3. Some of the older electric ones would whine like the tornado sirens at a similar pitch, I am a spotter. That’s almost like putting a siren on your car. Fine for one minute at 10:00AM Saturday for the monthly test.
    It would seem that intake noise is as bad, there is no tube or muffler in the intake it’s just right there at the surface.
    Our city says leaves may be raked into piles a foot away from the curb to 4 feet out. Leaves, nothing said about blowing or grass. Anything blown out into the street by so many “professionals” is not allowed and dangerous. NIMFY (like NIMBY) but the street looks a mess.

  4. Physics demands that ANY modification of that air stream will weaken the effective force of the air going through it. They cannot possibly have the same air power they had without the modification.

  5. Best quiet replacement for a gas powered or electric powered blower was invented hundreds of years ago. Buy a rake and a broom. Quit being lazy and spare our ears.

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