Set up process made easy.
Some time ago I came up with idea of having hydraulic leveling system in my 26' Argosy. Over the past winter I have worked diligently on my lathe turning aluminum piston cylinders of 1.500" diamemeter ID and 5" stroke. Since my recently built Stainless Steel frame is 6" tall I was able to keep the piston tube 6" long overall while having 5" of piston stroke.
Realizing that leveling can be achived within 5" of piston travel I have designed four aluminum jack stands with 0.5" adjustment capability. Holes in the square stock are drilled at 1" centers. The outside tube on the other hand has two holes at 2.5" centers. This allows for 1/2" adjustment. Here is a pic of the base jack.
Above pic shows a trailer supported by piston rods on top of the jack stand. Jackstands weigh only 3.5 lbs. They are shown placed on top of cinder block to gain 3' height for comfortable working condition during installation. The system as tested is capable of lifting the trailer wheels 3" off the ground when the trailer sits at rest on all four tires. Since the hydraulic pump is operated by 12 Volt
battery, the tire changing on the road can be done with ease.
Hydraulic pump is a Parker Oildyne. It is commomly used in Mercrusier Stern Drive power plants as Outdrive trim pump. It is capable of delivering 2800 Psi on the up circuit and 800 Psi on down side. Pump has a three wire motor and the polarity is controlled by energizing polarity reversing solenoids. On the up circuit hydraulic fluid is pumped into up manifold with four Peter-Paul SS electronically controlled hydraulic solenoid valves. By utilizing 12 one way diodes in the circuit I am able to open one two or all four solenoids at any given time for up circuit. Down switch opens all four solenoids to retract pistons. The reason for the 12 diodes is to prevent backfeeding unwanted circuits. To minimize size of the hydraulic lines we have used highly ressistant to corrosion Ez-Bend 3/16" brake tubing.
Fluid flow is regulated via manual adjustment vale shown just above yellow fill cap. The remote control cable plugs in on the street side of the trailer at the rear of the trailer and the 25' control cable allows me to walk around the trailer.
Remote control has two power up switches. One for up and one for down mode. In up mode the four switches operate the pump motor in up mode and each hydraulic solenoid individually, in pairs or all four. For down circuit I have chosen to use only one switch to operate all four hydraulic solenoids and reversing the pump motor at the same time. One way diodes separate up and down functions thus preventig crossfeeding.
Our system worked flowlesly when tested and it had to be slowed down a bit in order to have more precise control. Being able to set up jacks within 1/2" of the piston pin leaves us a 4.5" of lift. Jack bases have four Panhead bolts on the underside which helps with stabilty od the jacks. Top of the jack stand have recess to prevent the piston pin from slipping off accidently. When leveled the trailer sits rock solid. My determination to develop this system finally paid off and as ussual my wife Margaret is very proud of my accomplishment. Thank you, "Boatdoc"