How Lawn Mower Blades Cut Grass (at 50,000 FRAMES PER SECOND) - Smarter Every Day 196

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    Publicerades den 2 år sedan


    1. ZetPerson

      At 6:03 my stepdad walked in and told me to go mow the front yard

      1. Ghislaine Swinburn


      2. ramy moufied

        @Jachui lldkxnzl

      3. william killingsworth

        Set the deck really low and kill all the grass. He’’ll never ask u to mow the yard again.

      4. 981porsche

        Jachui: If you put the exact name of the channel in your comment, the channel owner will get the comment in their feed. So, remove the space between Smarter and EveryDay, so he will have a better chance of seeing your message out of the thousands posted on his videos.

      5. Justin Weddle ツ


    2. Edwin Dude

      Next film should be a chainsaw. I’ve never seen it in slow motion.

    3. Chad Speece

      You should really look Into golf course mowing. Way more precise would make an excellent video!!!

    4. chuck summerlin

      I can’t believe I just watched this or that the motor was taken off to cut a hole that was directed at him. I seriously doubt someone who mows all the time doesn’t know about vacuum

    5. Alastair Dent

      Hmm, I'm guessing that you don't have cylinder mower in the USA (or they are unusual). Rotating blades that pass over a static edge, 'shearing' like scissors.

    6. Liam Pawlowski

      What happens when an autonomous lawn mower detects a person

    7. PANIK 24/7

      Loved the video and looking forward to see the series! But do you know that replacing lawn with bushes could have a great positive impact by capturing C02 and reducing the heat absorbed by the soil?

    8. Alex Ganschow

      This is what turned me on to reel mowing! Reel mowing is a clever way of "scissor" cutting grass using a spinning reel cylinder with blades, referencing against a bed knife. You can imagine this method is better for the grass because if properly "tuned", the reel mower avoids (or minimizes) tearing of the grass blade. You're probably aware of this already, and the rotary method is certainly more interesting to investigate! But I hadn't seen this mentioned yet.

    9. Jacob Conde

      I have a question... How are babies made?

    10. Paulpap1986

      A reel / cylinder mower works like scissors. Lets see a slow mow of that. You need to sharpen your blades FYI. Thanks for the vid.

    11. TheFruitMugger

      4:14 "Well, as you can see, it sucks as it cuts!"

    12. Kelly Gardner

      This is two years old now, sorry, I am catching up. Anyway, when I worked for a city streets department, one of the kids who mowed lawns for our parks department brought in mower to the shop and said that it "wasn't cutting very well and needed the blades sharpened." After he left the shop manager said some colorful things about the kid not understanding his equipment and told me that this particular type of mower uses a flail rather than a blade and that the "flails get sharper as they cut" and that the reason the kid thought it wasn't cutting the grass well was because he was driving faster than the mower could cut. This was a rural area and I am from the suburbs, I didn't know what a flail was until I looked under the mower. However, I am still confused as to how it could get sharper as it cuts. Is that just something he was saying or is there some way a blade, or in this case, flail can actually become sharper as it cuts more grass?

    13. Justin Boonzaier

      Those tabs are to guide the grass into the catch bag.

    14. Pyrenees MTB

      Can we see a video of a chainsaw cutting wood?

    15. Mureithi Kivuti

      You know the guy loves his stuff when he even discusses lawnmowers with his barber

    16. Akeno

      my skin started itching just looking at him laying in the grass

    17. Mike Ramey

      A mower with a reel is like scissors.. you should do a slow motion video of that.

    18. Mega destroyer man

      “Don’t modify your lawnmower” Me with a 60mph racing lawnmower”

    19. Bobby Johns

      scythe and those helical blade no battery or gas push mowers.

    20. Bill Wedeman

      For precision cutting like on a golf green there are reel type mowers that use the opposing force like the scissors. The reel actually predates rotary mowers and in the early days the most common one didn't have a motor.

    21. TungstenCarbideProjectile

      there is no vacuum going on here

    22. TungstenCarbideProjectile

      Why are you not using a super bright light to illuminate inside the lawn mower area to get actual high speed footage? Your lack of proper lighting is ruining this whole thing

    23. David Wolford

      A scythe works by slicing motion not chopping

    24. SLDRCK Of Ages

      I don't know if anyone has ever said this but you and your wife look a LOT alike. I would have bet you were siblings if I didn't know she was your spouse. This is a cool video too.

    25. Michael E

      Twelve years ago I bought a replacement lawn mower blade that was supposedly optimized for "mulching". Behind the regular blade edge with the upward tab, there was a notch, then a second blade mounted higher and angled downward. When I installed it, I noticed two things immediately: 1) the mower was significantly quieter; and 2) cut quality was exceedingly poor. That's when I learned about the vacuum created by a mower blade - which was cancelled out on this blade by the extra downward-facing cutting edge. The aerodynamic changes related to the lack of vacuum were also apparently responsible for the reduction in noise. I took the blade back for a refund and have used standard blades ever since. Another fun fact: The tab on the rear of the blade can eventually wear down from friction against the grass clippings it's pushing upward. I've gone through two heavily used blades that, in addition to having a lot of material worn off the front from repeated sharpenings, had the rear tabs (which gently curved upward) worn down to a knife-edge.

    26. Gods Squad

      This video is awesome and I’m a barber and I’ve cut hair with vacuumed clippers for 20 years so my second favorite thing is striping grass

    27. Randy Dunn

      robot lawnmowers, design? R&D? ready Go!

    28. Joseph Lashley

      I used a two wheel tractor with apposing scissors action on the front. It had a skid to cut close.

    29. Sarith Shaji

      4:53 Never be ashamed of learning new things even when you are an expert in it. It makes you much stronger.

    30. Jerome Paul

      Ole boy needs to sharpen those blades!!!!

    31. Richard fitzwell

      I work in plastic extrusion. I'd love to see the melt happen in rt.

    32. GC plays

      I want to know how the mower deck doesn’t fly off from the forces of the blade and how the blades are driven from the engine.

    33. King Peter

      Men mow the grass with a scythe

    34. Stressy Porkrind

      Yes I do have a question some new Mowers have counter rotating blades how can the counterclockwise blade cut grass wouldn't it be using the backside of the blade help me? 😁

    35. Louis Potter

      No wonder why it’s harder to mow when the grass is wet. The blade can’t lift the grass up because the water/dew adds up to the weight. This is very educational. Thank you for posting this video. I highly appreciate it!

    36. Abdul Rehman Khan

      Your barber is a genius

    37. Justeen

      Great content 👍 love the show.

    38. Max Doneen

      Just like a golf club

    39. Ghislaine Swinburn

      I couldn't hear this video because of a lawn mower

    40. Clyde Perrine

      When you cut a piece out of the deck you alter the airflow. Simply put see through material (Plexiglas, plastic or any other see through material you can source). This will restore the airflow dynamics of the deck won't it? I have a Honda walk behind self propelled model that has two blades. Show how it works for us.

    41. M Hansen

      Does a flat square blade cut grass better then a angled blade

    42. Nathan Nolan

      I am a lawnmower mechanic and I approve of this

    43. Dab The Goat

      Dabbing Goat's Lawn Mower

    44. pop52pop

      I would like to see how the rear discharge mowers works. Blew the engine on my older zero turn mower and just ordered a rear discharge Grasshopper zero turn.

    45. Pat

      You are talking about rotary high speed mowers, cylinder mowers and finger bar mowers work just like scissors, and last time I looked combined harvester still used finger bars (but not most hay mowers).

    46. Scaredboy23

      when they slow down the footage then speed back up it sounds like a helicopter

    47. Bass Mechanic

      Your mower cuts better when you square off the edge of the blade. If you leave the edge sharp it cuts good for a few minutes then it's dulls and ends up ripping your grass, which leads to your grass becoming unhealthy. The square edge stays square longer and makes a clean cut.

    48. Konstantin M.

      Are you mowing your lawn everyday? No I am moaning about lawyers every day!

    49. No Shorts


    50. RossDynamicsLab

      Is there a best speed to push the lawnmower? That is, if I want to mow the most area per minute, but also have a quality cut, what is that 'sweet spot'? If I mow very slowly, I get a good cut, but don't cover much ground quickly. If I mow too fast, I can cover a lot of ground, but I'm sure the cut will suffer. Can physics shed light on this subject?

    51. Brian Cantley

      Speaking of lawn "tools", how about on the greatest of lawn tools, the symbiote grazers, like cows, and sheep, and though they are browsers, not grazers, goats. And how they use their front top teeth to shear grass. (That last sentence was a bit of a trick)

    52. Sarah Cole

      hand tools question: whyis my 'grass hook' blade bevelled on the underside only?

    53. Methyl Ethyl

      Could you do an examination of whether your lawn will look better mowing fast or slow? Same if the grass is wet or dry?

    54. Everyday Guy

      Do a slow video on the gator blades!!

    55. Daniel Stuart

      Why does wet grass cut so much differently than dry grass? That would be cool to see. Thanks for what you do! Dad + 2 love your show

    56. Jon Ocampo

      You said don't modify your lawm mower just in time...

    57. Jamie Landis

      I figured this out while shopping for new mulching blades. They talk about air lift just like the blades of a helicopter.

    58. MR BILLY

      Sorry I’m too smart for this guy I am out

    59. Booga_8 Plays

      This video is oddly satisfying

    60. Ruben Perez

      The tab helps throw the cut grass out the discharge area as well

    61. Stephen Floyd

      Hey I'm a professional landscaper, check out the honda commercial mower hrc 216 hxa, they are 21in mowers with 2 blades! I have been using Honda mowers for over 25 years! Great video, hope you go more in depth on lawn tools.

    62. Vaisakh Kalarikkal

      7:38 wtf

    63. TBoy205

      when ur doing your phd in aerospace engineering and didn’t think about the aerodynamics of the mower blade and its wing on the back

    64. Rat

      One video you're on a nuclear submarine, next video you're slow-mo mowing the lawn

    65. Dallen Haven

      I learned that they create an airflow type of vacuum when I was 5 years old watching Honey I Shrunk The Kids and they almost get sucked up into the lawn mower. That’s about the same age my dad also let me run the lawn mower by myself, and taught me how it works and how to be safe with it

    66. Justin McNeal

      Imagine looking next door and seeing a guy laying down in the grass cutting paper

    67. Toxinical

      This man has a lot of strength to lay on the grass without itching

    68. Shweta Sharma

      What I think so , the blades act like a fan which creates a low pressure at the top , pulling the grass upward , while the blades cut the grass. Thank you

    69. Deep Water

      There is something that cuts grass like scissors. It is called a sickle bar or a hay bind.

    70. Samuel Lawrence

      I love this, destin

    71. Samuel Lawrence

      0:18 destin’s energy is so contagious it reminds me of me as a young kid. I want that curiosity back

    72. john smith

      Lol gotta love those cabbage and celery sounds for the slow mo!!!!

    73. Paul Muhrbeck

      If I kill the lawn I don’t need to cut it’s hair, no sorry the grass

    74. Will Graf

      Actually high lift blades work great for tall, thick overgrown grass but for your best cut using a regular mower and not a reel mower, a low lift or “contour” blade will give the best cut. I’m a 28 yr old AU hort grad who lives in Cullman. I own a landscaping company. Keep up the cool content 🤘🏼

    75. Fireball_720

      Wow even I knew could infer that the blade creates a lift pulling the grass up. His brain was probably not working that day or something

    76. Patrick O'Rourke

      What would happen if you were to sharpen the lawnmower blade??

    77. Brent Lockhart

      have you never watched hunny I shrunk the kids

    78. Daniel Cabrera

      How does a mower cut grass at the center of the blade, like where it’s rotating.

    79. 4 Chan

      Hammer down the tab on the blade and see what happens

    80. Bobo342

      Lawn mower nah High speed ultra choppy choppy thing

    81. P. S

      So, they're not cutting but smacking the grass..

    82. ThatRacer Guy

      You've covered a rotary blade mower... Now explain the one I grew up pushing... The front discharge mower that looks like a mini combine... Oh wait, I just had an "Ah-Ha" moment. I just Got Smarter!!! Lol.

    83. Jack Briggs-Keating

      To be fair, an old school push mower uses a similar system to the scissors 😄

    84. Andrew

      I'd be curious to see the science for a mulching blade since there is no lift.

    85. haugstule

      hey Destin, all of the blades you you shown here are dull, sharpen, balance and redo please.

    86. David Sanders

      Way up nord we use snowblowers. How does it shoot the snow into the neighbors driveway?

    87. Chasegaming

      I think also maybe how lawn mowers work is that the speed of the blade spinning maybe creates a suction and pulls the grass I haven’t watched the entire vid yet tho

    88. Macdaire j

      A video on tractor mowers would be cool

    89. muppet_ rcls


    90. Mike Rollings

      What I would like to see is put guages on the mower deck to see the air pressure difference.

    91. Corbin Bailey


    92. ChinsHyperBTW

      You wonder why when you’re not cutting grass there’s air flowing out the bottom you could even use it as a on the sidewalk as a blower I mean because it shoots there and it was definitely move the grass out-of-the-way on the sidewalk because of the air

    93. Revere

      *cries in grasshopper*

    94. enkrypt3d

      now do one on a reel mower!

    95. James B.

      How dose a pressure washer work

    96. Mens B

      reel mowers come on brother

    97. Logan Seefeldt

      Do a chinsaw in slow motion

    98. flynbenny

      I run a reel mower, that would be a good one to look at for the lawn tool series. It is basically rolling scissors though, I sharpen it with lapping compound.

    99. Chase Loveall

      Have you seen Honey I Shrunk the Kids? They had that vacuum part in the movie when the lawnmower was coming over. Fascinating the movie understood the dynamics of a lawnmower.

    100. RossTheSloth

      you can hear every time the engine makes an explosion and the piston goes down, Not the reason for the video just though it was cool