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Fittings: At the time, schedule 40 black iron pipe was the order of the day. There were some problems with cast iron fittings. It soon became evident that malleable iron fittings were required. Fittings then moved from schedule 40 to schedule 80. The galvanized elbow shown on the drawing would probably have been sufficiently strong, however, galvanized fittings should never be used on hydraulic or pneumatic systems as they tend to shed flakes of galvanizing. The fittings should be machined type fittings, especially if they are to accommodate 2000 psi or more. The valve should also have a relief set at 1000 psi. Many of the old Gresen valves that were used were only designed for 1500 psi.
Cylinder: The cylinder is a standard 3" x 18" stroke agricultural cylinder. There are a number of makes of these but the one shown in the picture has 1" bushings on both the rod and piston ends of the cylinder. Before building the brackets for the cylinder, you should have the cylinder on hand. Some cylinders have rods that tie the ends together and may require more room. The cylinder should also be designed for at least 1500 psi working pressure. See farm equipment suppliers.
Valve: The valve is a 4 way 3 position double acting open center standard type with ½" national pipe thread ports. The spool is spring centering. A self releasing detent is handy for the return position. The valve should also have an integral relief valve set at about 1500 psi. Gresen is one brand. Only use hydraulic plumbing fittings for safety.
Construction: All parts of the structure are welded. Do a good job of aligning parts and tack welding them before doing the final welding to minimize warpage.
It is not recommended that the splitter be used to split both forwards and backwards. This would put too much stress on and bend the rod.
Power Options: The log splitter was designed to operate off tractor hydraulic systems. These systems have changed substantially over the years. The older systems produced pressures of 1500 psi to 2200 psi. New systems produce up to 3000 psi. The 3" cylinder used has an area of about 7.07 square inches. If you multiply this by the pressure of 1500 psi, the cylinder will produce about 10,000 pounds of force. If 3000 psi were used it would produce about 20,000 pounds of force. Either of these systems would split most any log that would be practical to manually load into the splitter. It should be noted that the best splitting is done through the center of the log. If splitting the long to one side of center, large knots can be a problem.
Hydraulic power for the unit can be supplied by a gasoline engine. Hydraulic power units are available that include a pump, tank, filters pressure relief valves, and a control valve. They can be driven by an electric motor or engine. Gasoline engines should be sized at least 30% larger than electric motors required for the hydraulic unit. Tractor hydraulic units that would be used for this splitter generally produce about 15 gpm at about 2000 psi at rated RPM. Because the tractor would generally run at a fast idle, a hydraulic unit capable of about 8 gpm and 1500 psi would be sufficient. It extends the cylinder in a little more that 4 seconds. A pump this size would require a gasoline engine of about 12 hp. If you are making up your own hydraulic power unit with separate pump and engine, be sure to carefully match the engine with the required pump speed and power.
There are many suppliers of log splitters. Search the web using the phrase "logsplitters"
Building the wood splitter
This log splitter includes the cylinder, valve and short hoses used to connect these. It can be mounted and made transportable with a tractor. An engine and pump could be added so that it would be a self contained unit, moveable by a pickup truck.
It takes about five hours to build with two people involved, but it will split a pickup load of wood in about 30 minutes.
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| Figure 1. Elevation | Figure 2. Plan View |
List of materials
- Main member - 3" x 6" I beam - 48 "long
- Left end - 4" x 6" x 10" box
- Push block - 4" x 4" x 1/4" angle iron - 6" long
- Space and guide = to match flange of I beam - bolted together
- Cylinder - 3" x 18" stroke
- Control valve bracket - 1/4" flat iron
- Control valve with detent for auto stop on return stroke
- Wedge - 71/4" x 3" wedge - 6" high
- Wedge support - 1/2" x 6" x12" flat iron
- 4 - 5/16"x1 1/4" bolts with nuts and washers
- Triangular Push block support - fabricated from 3/16" iron
Figure 3. Hydraulic cylinder with control mounted on side (not recommended).
The control valve mounted on top as shown allows for easy access to the controls
from both sides.
Figure 4. The splitter can be easily mounted for transportation. In this figure
it is mounted on an old sprayer chassis with 15" wheels.
Figure 5. & 6. show the pin connection at either end of the 18" cylinder.
Figure 6.
Source: Agdex 788-1. Revised 2002.
The contents of this page are no longer available.
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