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New Axe Design Employs 2 Simple Machines; Chops Wood Splitting Effort in Half

New Axe Design Employs 2 Simple Machines; Chops Wood Splitting Effort in Half

If you’re from a frigid woodland state like I am, chopping wood was a permanent fixture on the list of household chores growing up. And unfortunately for us Northerners, as technologically advanced as society has become, there still remains no more practical way to make kindling than swinging an axe. But thanks to a simple twist of physics, this backbreaking task may have just gotten a bit easier.

A Finnish inventor with a name every bit as cool as you’d hope, Heikki Karna, has invented a revolutionary new axe called the “Vipukirves,” a Finnish word which translates to lever axe. In addition to capturing the mechanical advantage of the wedge, it also manages to utilize the effect of a lever.

Regular axes just use the wedge effect and need to be driven downward with enough force that the axe head can split a log along its grain. For anybody who isn’t Paul Bunyan, this usually requires a few swings (and maybe 3 embarrassing whiffs) to actually get the log to split. But the lever effect means that a single swing of the axe can create a split in the wood that is 8 cm wide – a distance that will usually mean the log is now two logs.

Here’s how it works: As you can see, the axe head is actually set off to one side. This means that when the blade enters the wood (purely on the force you give it) the axe head naturally rolls over to one side and immediately starts acting as a lever to push the pieces apart from one another.

Axe IP

The basic physics behind the Vipkirves. (Vipukirves.fi)

This design is especially good news for those axe swingers who don’t appreciate the sudden shock of impact on their supple wrists. Because the Vipukirves rotates immediately after impact, some of the energy is dissipated through the axe head instead of being sent back to the handler.

Tell us what you think, nerds of the Northlands – is the mechanical advantage of the Vipukirves worth the $215 price tag, or are you willing to stick to one simple machine when it comes to wood splitting?

HT: Geek.com

Comments

  1. J.C. Richardson III says:

    Wood to small to burn in wood stove. It will burn up to fast.  Log that size would make four nice pieces to burn in stove or fire place. 
    The pieces he was splitting would be nice to burn in a fire place to watch with girl friend.
    I split a log that size into four to six pieces.  I would put six pieces in my wood stove and it would burn all night.  Log needs to be a little longer also. Would cut my logs by using chainsaw as ruler. Cut the length of motor and bar together.  Around 26″. I built my stove around 30″ deep. I’ve built a lot of wood stove in my welding shop. Not all would be that deep. A little smaller for most to sale.
    Plus I built wood splitters also.  Works great with wood with knots. Not sure how that axe works with a tree full of knots. Think his arm will be tired after a log or two.  
    Thanks everyone for putting up with me. I’m gone fore now. JCRIII

  2. john steele says:

    It looks to be a very good product, and the aspect of the axe has been evolution, the price is a little high it needs to be lowered greatly for it to meet the public demands. 

  3. Hello.

    My name is Heikki Kärnä. I am the inventor of the Vipukirves/Leveraxe.

    I red the comments and I noticed, that for some people it seems to be very difficult to understand the splitting technique with the Vipukirves/Leveraxe.

    There is practically nothing to do with cutting and wedging when splitting with the Vipukirves.

    Leverage is the way how to do it.

    There is no friction as with the conventional axes and mauls, because on an optimum strike the blade penetrates into the block only about 5 millimetres, less than a quarter of an inch. At the very moment, when the edge of the blade touches the surface of the block, the blade starts to lean to the right. Here comes the leverage that multiplies the splitting force up to 35 times bigger. The edge of the blade grabs to the side of the part of wood. All the kinetic energy turns to the left and pushes the piece away. Initial spitting force can be even 15 tons.

    Splitting is now much easier, because you do not have to use so much power. By holding the handle as gently as possible you allow the rotation in your hands. You will not get such chocks to your hands and body as with the conventional axes and mauls.

    It is very important to hold the handle so, that you do not resist the rotation.

    This way also the safety elements, which are build in to the design of the blade, function as they are planned to do. The blade will stop on the top of the block, or slows down the speed so, that it is fully under the control of the user.

    Vipukirves has been on the market over 8 years. There has happened NO ACCIDENT.

    It is advisable to split the wood as green as possible, because this way it splits easiest, the insects cannot multiply in it and it dries best.

    Vipukirves has spread all around the world. The feed back is excellent.

    There is a lot information in my websites, Google etc. Youtube. Search by words Vipukirves and Leveraxe.

    I wish you to make yourselves acquainted with this new kind of tool which is in commercial production first time in the history. I would also like you to understand that among the other advantages the safety elements make the splitting really enjoyable because you do not have to be afraid all the time about the blade.

    Based to the feed back, so called hard wood is not any more a problem when using the Vipukirves.

    Of course it requires some knowledge about the structure of the tree to optimize the splitting.

    In the videos you can see myself splitting. I am around 70 years. Now I am 74 and my total experience in splitting firewood consists of 67 years time.

    Read more: http://www.mnn.com/family/protection-safety/stories/weve-been-splitting-wood-all-wrong#ixzz39J21SVBf

  4. Steve says:

    Several questions.

    How long would it have taken to split that wood with another ax? It seams like the wood was very dry and ready to split.

    When will this be available at a more reasonable price? Special design aside, it is a forged head with heat treatment. just like every other ax on the market, and will be quite simple to mass produce and the current price is well above the law of diminishing returns.

  5. Nancy says:

    I would like to see them split a twisty gnarled old piece of blackjack oak, or hickory, or something really hard like what grows around here, I dont think it would split so nicely.  There are some oaks Ive put under my log splitter that IT couldnt hardly handle.  Im terribly skeptical…

  6. nate says:

    Try hard wood..

  7. Dave says:

    Oops, spoke too soon. There is some birch in there towards the end. My bad. Still seemed to be much straighter-grained than what I’m usually dealing with…maybe the axe is so good that it makes the job look easy? 

  8. Dave says:

    The bigger advancement to me is splitting the wood in a tire. That sounds like VERY dry wood, and it’s extremely straight-grained. Nearly any axe could do that with wood like that. Show me what it does with beech, birch or oak…in other words, what LBJ said when I was beaten to it…

  9. Scaramouche says:

    No redneck American is going to be impressed by something that relieves them of the right to look tough swinging an axe, bare chested down on the farm. Especially when it has been invented by a European.

  10. Jeff Jenkins says:

    Cost 280 US (Due to our dwindling dolllar)

  11. cyn says:

    ALL types of wood .. I would like to see this w/ OAK !!

  12. robin wood says:

    nothing new any axe can be swung with the centre of gravity off to one side, it is the way anyone with experience works and can easily be learned. This is a very expensive gimmick http://www.robin-wood.co.uk/wood-craft-blog/2014/04/24/axe-nothing-new-expensive-gimmick-people-money-sense/

  13. Stephen Cruster says:

    But the article doesn’t say how much he chargers to split the wood. Basic info I would need in order to consider this further.

  14. Erock says:

    $215 buys a lot of gas for my log splitter. I too see wrist injuries happening with that axe. Let’s see him do that with a Elm log that spent its whole in the wind. Now the tire is a good idea. K.I.S.S. When I fell a tree there is always a bunch of dead branches of varrying sizes if I need kindling.

  15. Richard says:

    I am an inventor with 15 patents. I would like to see the same motions with a regular heavey axe.

    However I like the tire idea.

  16. Daruth says:

    As a longtime wood cutter I would have to agree that that wood looked ideal. Never needed help with that kind of stuff. If there were a knot in the wood I would think the shape would prevent one from chopping further down into the wood to break a difficult area.

    Demo this axe on knotty pine.

    They mention the impact not being transferred into the handle but I would think the sudden twisting action would be painful or harmful on the wrists.

    They make mechanical wood splitters for as low as $500 which takes most of the work out of it. Seems pricey for an axe you still have to swing.

  17. Johnny says:

    Yeah, uhm. Nevermind the axe, the tire nailed to the stump is the real genius here.

  18. darkelf says:

    How much damage does it do against dwarves and trolls? 1d8? 1d10?

  19. wayne says:

    tire is a good idea , to much cash for me

  20. Paul Bunyan says:

    http://www.northerntool.com/shop/tools/product_200422062_200422062

    Here is an electric log splitter for $50 more…

  21. Paul Bunyan says:

    Do they come with a box of tampons? But seriously If I were gonna spend that much money to split wood then I might as well buy a powered log splitter.

  22. lutz says:

    Who sells the tire screwed to the log?

  23. Tim Murphrey says:

    Chuck has obviously never cut wood…

  24. Baker Vinci says:

    Good Lord; enough with the zombies. The concept is great, but I would certainly be skeptical about a wrist injury. The wood in the demonstration is unlike the wood that most of us in the southern swamps will have at our disposal. Has anyone split ash, oak, pecan, willow, or sycamore with this thing? I also like the tire set up. Simple, but brilliant. Baker Vinci

  25. Tiffany says:

    this is awesome, way to improve on the wheel guy. weird to find it on Nerdist but i guess it’s a tech-gadget? and definitely necessary apocalypse gear!!

  26. Bryan says:

    In the video you see the ax turn a complete 90 degrees on impact several times. That is an accident/injury just waiting to happen. He is making pretty quick work of clear straight grained logs. Id like to see how it does on a gnarly piece of applewood or something similar. I can cut up straight oak about as fast with a standard axe. For the price tag you can buy a decent used power splitter. Now the tire on the chopping block I like that idea and will give it a try.

  27. Brian says:

    But how well does it work against zombies? Come on… that’s what we all need to know!!!

  28. Kyle says:

    I think I’ll just wait for Fiskars to make the same one under $100

  29. LJB says:

    If you notice in the video, they demonstrations they do use preselected logs with VERY straight-grain and are dry/frozen. Hell, using a normal ax, it doesn’t take too much force to split one of those types of logs. I want to see how it does with a log that has a knot in the middle of it or just a log that isn’t an “ideal” cut.

  30. Jake says:

    Chuck may have a point about injuries. I’d want to play with one before forking out a couple of Hundy on it.

  31. Fangirl71 says:

    I’m with “emeraldnite,” How well does it work on under skulls????

  32. Daniel says:

    Drill a few holes in your axehead and bolt an old wedge to the side.

  33. Doug says:

    I will wait for the $10 Harbor Freight version and with my 25% off coupon I can get it for $750…

  34. Jordan says:

    I could just make one for less than that…

  35. emeraldnite says:

    Logs are well and good, but I think what everyone here is really wondering–is it good for killing zombies?

  36. Matt Manley says:

    He is on the Nerdist because this man is a fraking artist…

  37. Howard Abraham says:

    It makes me want to split some logs.

  38. Chuck says:

    So the handle will twist in your hands every time you make contact with the wood. Looks like a surefire way to get a wrist injury.
    Seems to me that having the handle, center of gravity, and blade all lined up would also improve accuracy aside from helping to avoid injury. I will be avoiding this product.

  39. Jessica Duffy says:

    It’s on nerdist cause its sciencey and all things sciencey are therefor nerdy. Being a nerd is way more about getting excited over new axe designed using simple machines then it is about geek culture.

  40. Fish says:

    It’s a super simple application of physics to a longstanding high-labor task. Very cool and totally up the alley of the Nerdist flock. And while it might be expensive now, that’s to be expected for any next-step technology right when it’s introduced.

  41. Adam says:

    I’ve cut A LOT of wood and it seems like it would be neat to try out but do I think it’s worth $215? Nope. Sure it takes a less forceful swing but the rest of your body will tense up and you try to chop faster resulting in the odd body movement you see in the video. Frantic chopping leads to accidents. I’m glad I have gas heat now.

  42. That looks very useful, but at that price, I could hire someone to split the wood.

  43. Ben says:

    I get why it’s a good axe but why is it on the Nerdist site?