So for some more details:
Firstly go to this website. It is in swedish, but contains a lot of photographs. Also an improved version of the one in the video is featured. Also another type where a spring works with tensional force instead of compressive (as the suspension spring does). http://www.pidia.se/ingmarsklyv.html
Materials and dimensions are:
- The spring comes from a car suspension. It is 43 (~17 in) cm long unloaded, and 29 cm (~11½ in). The steel diameter is 13 mm (33/64 in) and the whole spring is 16 cm (6 19⁄64 in) diameter. The part of the spring that moves comprises 5 1/3 winds. Trial and error would make other springs work too.. The splitter that uses tension springs (pulling the spring) are easier as you can combine several springs.
The spring sits in place only by means of the weight on top of it and by the aid of small blocks welded as seen on this picture:
- The shaft on which the axe head and weights are welded used was from an old harrow and is a square (hollow) steel bar with the measurements 75x75x4 mm (2 61⁄64 x 2 61⁄64 x 5⁄32 in) and 128 cm (50 25⁄64 in) long from one end to where the axe and weights are welded onto it.
As you can see the shaft has been hightened approx 8 cm (3 5⁄32 in) at the hinch to leave more space for the spring.
The weights and axe head are quite long (62 cm or 24 13⁄32 in) , and the handle has been placed fairly high to avoid having it in the way of the splitting wood. Among other scrap steel, hydraulic arms from a tractor were used for weight and welding the axe head onto.
These weigh 38 kg (83.8 lbs) alltogether.
The Axe head and weights should be welded to the shaft with a bit of an angle towards the hinch in order to direct the force directly from above onto the firewood log. Otherwise the axe head will be pointing slightly towards the operator as it travels in a circular motion.
The tip of the axe should be hovering an inch or so above the firewood log you intend to split when resting on the spring. Otherwise you have to lift the axe to place a log on the chopping block. A tip is to keep the cleaving surfaces that come in contact with the wood clean from rust to limit friction. Keeping the axe sharp is also important as this allows for the axe to cut through knots etc. This is of course optional. It can also function with a round edge for minimal risk of cutting injuries. Height of the axe position can be adjusted by moving spring closer or further away from the hinch.
- For a handle you can pretty much choose whatever you think will work for you. Don't go too thin as this may be uncomfortable.
- The hinch needs to be very robust and the one used here is from an old 'grip' from a small forestry tractor.
Be creative and find some steel bars etc for the rest of the construction.
To give a rough idea of the remaining measurements I will comment on the following picture:
The long steel bar on which the hinch and lower spring platform are welded onto measures approximately 155 cm (61 1⁄32 in).
The lower components in the frame forming a 'V' measures: The right side pair: 95 cm (37 13⁄32 in) and the left side pair: approx 75 cm (29 17⁄32 in).
Distance between the 'legs' comprised of the 'v' frame is 100 cm (39 3⁄8 in).
Lower spring platform sits approx 92 cm (36 7⁄32 in) above ground/feet.
Distance between where the 'v' frame joins onto the longer steel bar is approx 115 cm (45 9⁄32 in).
The left side of the 'v' is cast/imbedded in a block of concrete. Alternative would be another frame construction, bolting it to a floor etc.
The sturdier it is, the safer and more precisely it is, too.
Here he is making kindling using this big contraption, showing it is versatile.
If you keep the hinch well greased it should function without making much noise allowing you to enjoy the birdsong or a trickle of water while splitting wood