Has anyone thought or built a hydraulic levelling system for their Schoolie?

[JESUSBUS]

Originally Posted by thjakits

E.g - buss stops right front corner way low!

- start your hydraulic pump
- open all locks
- feed hydraulic pressure until the bus moves somewhere
- stop the feed
- lock left rear cylinder
- lock left front cylinder
- feed hydraulic pressure - until left/right level shows the bubble centered
- stop the feed
- lock right rear cylinder
- open front left cylinder
- feed hydraulic pressure - until for/aft level shows the bubble centered
- stop feed
- lock all cylinders
- switch of hydraulics
- DONE!

Actually writing this takes more time than I would expect the leveling to take!

Obviously depending on how big that pump is!!

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.

[thjakits]

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

[HamSkoolie]

Originally Posted by LargeMargeInBaja

.
Four at 7.5-ton is 30k... yes, in theory.
.
In reality, as the vehicle rocks with wind or inhabitants moving about, could each of the four jacks be tasked with significantly different numbers... one corner more, another corner less?
As the vehicle shifts and settles, could one jack gap, requiring the functional three 7.5ers to carry the (potential) 32k load?
.
You sound like you are experienced with camp spots surveyed by a cock-eyed listing-sailor.
How does an incline challenge the 'four corners equal' theory?
Do the downhill jacks possess the structure and compacted ground to not merely wilt under one cheek of our plus-sized buffet-contestant?
.
Another point:
* four jacks presumes perfect balance on multiple axis
As, for example, water moves from a yum tank to a yuck tank, does the perfectly-balanced teeter-totter seek a new balance?
Would that re-balancing process require my attention during a time I would rather be napping, snorkeling, barbecuing, holding hands watching the sunrise?
.
If I was me with a 32k GVWR, I might sky-hook it with a half-dozen 10k jacks.
I prefer boring; maybe you like surprises?
.
*****
.
1998 on a caravan through Baja, we were sitting around the lanai next to a newer factory RecreationVehicle on its first tentative baby-steps away from home.
I made the innocent mistake of asking about a shimmering liquid on the base/pad of a jack strut.
The tender-foot owner looked under, then came half-way unglued... "WE JUST GOT IT OUT OF THE SHOP UNDER WARRANTY TO FIX THAT LEAKING [pile of rubbish]!", accompanied by much gnashing of teeth and rending of garments.
"PIECE OF [pile of rubbish] FACTORY RECREATIONVEHICLE! I WILL NEVER BUY ANOTHER [insert entire genre piles-of-rubbish with variations in decals] AGAIN!"
.
And, apparently, the rig was financed.
If I was me, I would be emotionally devastated.
My sense of abandonment would kick-in, and I would feel taken advantage of.
My faith in humanity, thrashed.
.
And worse, how could I trust my judgement, how could I ever again look at my reflection in the mirror.
.
But I encourage you to go ahead fiddling with your contraptions... with my blessings.

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]

[QUOTE=DeMac;458627]

Originally Posted by JESUSBUS

Has anyone thought or built a hydraulic levelling system for their Schoolie?

These members did.

Soujourner
ol trunt
GreyCoyote

Probably more. Just what I remember.

Mine are not hydraulic. I modified 8000lb square tube drop leg trailer jacks and bolted them to the frame near each wheel.

[TJones]

Originally Posted by JESUSBUS

This is what I am talking about. One new cylinder can cost up to 300 USD. An overkill landing gear like are used on commercial trailers would be great. I used to drive commercial freight and those landing gear are heavy duty. Can you help me with leads on how to acquire 4 of those as scrap?

They were from Pacific Steel and Recycling in Gillette, WY.

Ted