New Axe Design Employs 2 Simple Machines; Chops Wood Splitting Effort in Half
By Lenny Pierce on April 24, 2014
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.
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?