That is what i was trying to avoid. It would be better if four jacks had screw jacks at the ends, then when they touch down, they are shut off until the others also touch down onto the ground. Then when all four are solid it can go into a routine where equal pressure is given to all 4. The apparatus, I think should be regular landing gear off a semi trailer. One mounted front and one mounted aft, then a shaft that connects the two, with switches when they touch down. Then the hydraulics go into a high cycle producing pressure to equally lift the entire load.
Has anyone thought or built a hydraulic levelling system for their Schoolie?
That is what i was trying to avoid. It would be better if four jacks had screw jacks at the ends, then when they touch down, they are shut off until the others also touch down onto the ground. Then when all four are solid it can go into a routine where equal pressure is given to all 4. The apparatus, I think should be regular landing gear off a semi trailer. One mounted front and one mounted aft, then a shaft that connects the two, with switches when they touch down. Then the hydraulics go into a high cycle producing pressure to equally lift the entire load.
I think you have the wrong impression how that works...
IF you want for all legs to touch and then rise at the same rate - you will NOT level the bus, just jack it up at same attitude it is starting out.
IF you go with manual gear drives - even if you motor them - you will have to jack them a little at a time to level the bus. IF you are all "crooked" (inclined on both axis - lengthwise and across...) all your legs will be at different extension by the time the bus is level!
What you (seem to...) have in mind does NOT level the bus - it only stabilizes it - (no rocking in strong wind or moving while walking in the bus)
IF you are off-level, there is no way around for different length extensions - and these need to be done carefully, so as not to put undue strain on the frame...
[My example above is derived from Old Trunt's picture of his layout - I don't know if he pumps 2 cylinders at the same time, but I would imagine that the bus would level with that - all connected cylinders would level out according to weight on them... you create a pivot-line with the locked cylinders. If you do that by hand or my electric pump - hand is simpler and likely you don't need additional lock valves.... - I assume Old Trunt has double acting cylinders to be able to retract them.... the legs pretty much drop by their own weight or with very little encouragement by the pump - until they touch the ground. Once the pumping gets though - you need to start selecting pivot-lines - ....or there is no leveling!! ....just digging in the heaviest corner of the bus!!]
thjakits
IF you want for all legs to touch and then rise at the same rate - you will NOT level the bus, just jack it up at same attitude it is starting out.
IF you go with manual gear drives - even if you motor them - you will have to jack them a little at a time to level the bus. IF you are all "crooked" (inclined on both axis - lengthwise and across...) all your legs will be at different extension by the time the bus is level!
What you (seem to...) have in mind does NOT level the bus - it only stabilizes it - (no rocking in strong wind or moving while walking in the bus)
IF you are off-level, there is no way around for different length extensions - and these need to be done carefully, so as not to put undue strain on the frame...
[My example above is derived from Old Trunt's picture of his layout - I don't know if he pumps 2 cylinders at the same time, but I would imagine that the bus would level with that - all connected cylinders would level out according to weight on them... you create a pivot-line with the locked cylinders. If you do that by hand or my electric pump - hand is simpler and likely you don't need additional lock valves.... - I assume Old Trunt has double acting cylinders to be able to retract them.... the legs pretty much drop by their own weight or with very little encouragement by the pump - until they touch the ground. Once the pumping gets though - you need to start selecting pivot-lines - ....or there is no leveling!! ....just digging in the heaviest corner of the bus!!]
thjakits
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HamSkoolie
Senior Member
4 x 7.5 ton jacks is 60,000 pounds or 30 tons. The jacks we're looking at are 7,500 POUNDS so 30,000 pounds total. With a 31,800 pound maximum gross weight and no intention of lifting the entire bus, only lifting as necessary to level and stabilize while still having the suspension take the majority of the load, those jacks should be sufficient.
The other option we were looking at was air bags but they don't fit with the mission of the rig....... off grid up to a month without moving. Bag systems would likely have issues due to changing temps, ambient pressure, and even minute leakage thus requiring constant monitoring.
We want to set up and be done with it until it's time to move on in a week, maybe two, and up to a month.
We intend to take our rig, after aerial (via drone) recon for each next turn around, into BLM and other remote areas in various landscapes so we want the ability to lift the frame while allowing the suspension to maintain the lions share of the load. We won't be lifting anything off the ground, just getting some help with leveling when we find the perfect except for grade place to spend a few weeks.
sojourner-SKO
Senior Member
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TJones-SKO
Senior Member
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