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

[jjaj823]

Originally Posted by HamSkoolie

We are looking at putting four scissors on our frame. Each has a 7,500 pound capacity for a combined capacity of 30,000 pounds and our bus has a 31,800 GVWR which we don't expect to get near. In use we plan to leave most of the weight on the suspension and lift only enough to level and stabilize.

Where did you find your scissor jacks? Also, where did you mount them?

[jbeech]

So what kind of jack system have you got in mind? I'd be interested despite knowing I probably don't use it a lot because that one time I want it, it 'really' needs leveling.

[HamSkoolie]

Originally Posted by jjaj823

Where did you find your scissor jacks? Also, where did you mount them?

They haven't been mounted but will be mounted directly to the frame, hear the wheels to avoid any issues with clearance on changing slopes like driveway approaches.



I found them on Amazon. Under $200 for FOUR jacks with 7,500 pound capacity PER JACK. They are manual but that's no biggie as I'll just use a power driver and an extension.

[BFlinn181]

As a few have mentioned, leveling jacks can cause the frame to twist. Many RV owners have cracked windshields by using jacks incorrectly. I personally wouldn't depend on an 'auto-leveling system, I prefer to do it by pushing buttons myself. I mostly use them to stabilize the RV, not jack it up to level it. I can usually find a level spot or just use a couple of blocks to park on to provide comfortable parking for the night.

I've not seen bottle jacks that have the range needed to install as leveling jacks. Best to harvest a set from an RV salvage yard or install a leveling system that can handle the weight of your bus.

[HamSkoolie]

Originally Posted by BFlinn181

As a few have mentioned, leveling jacks can cause the frame to twist. Many RV owners have cracked windshields by using jacks incorrectly. I personally wouldn't depend on an 'auto-leveling system, I prefer to do it by pushing buttons myself. I mostly use them to stabilize the RV, not jack it up to level it. I can usually find a level spot or just use a couple of blocks to park on to provide comfortable parking for the night.

I've not seen bottle jacks that have the range needed to install as leveling jacks. Best to harvest a set from an RV salvage yard or install a leveling system that can handle the weight of your bus.

As has been said, an actual purpose built school bus is a frame upon which a body is mounted. The body being independent of the frame and the frame 100% independent of the body. Thus we don't attach seat belts to the frame of a school bus but the body because the two can separate.
And if you lift the frame, you're not going to deform the body or pop out a windshield unless you have some form of structural issue in the frame. Which would be good to know sooner rather than later.
Now, if you're talking about a "bus" that started life as a cutaway van or pickup chassis, it's going to depend upon how it was built and how close to maximum structural capacity the total rig is when completed.

I've worked on and driven cut away van chassis "buses" that were junk and I've worked on and driven them that weren't.
However, light truck and van chassis are not built like a BlueBird, Thomas, AmTran, IH, or Navistar purpose build school bus. The light chassis cut aways have frames that do indeed flex and I've seen them twisted permanently by improper lifting as well as improperly crossing a complex hard surface that resulted in lifting one corner to high while driving.
I'm not sure if there are any "buses" out there based on unibody construction but there probably are. Those would be the most easily distorted rigs. Heck yo can't even put a jack on them except in specially designated places.

[JESUSBUS]

Thanks for all your commentary folks. I propose that I will use my vehicle in various places not necessarily improved camp sites, so I though it would be nice to have a levelling system that could adjust for 12" TO 24" of differential terrain across the footprint of the entire bus.

My background is in machining, design, and manufacturing so the sky is the limit when it comes to a design project such as this.

I went on a camping trip 26 years ago with my family in a pop up van. The first campsite I went to, I spent 1 1/2 hours cranking up the pop top and then setting up an awning made out of a tarp. Because of this experience, I want my rig to be very simple and automated. This may not be your thing, but that's what I am shooting for. If my experience helps anyone in making practical decisions then maybe it will encourage other people to follow suit.

I'm also looking at my bus as my final home. It is stupid to invest in a house on a piece of land because you are paying taxes and giving your money away. If you want to live frugally, then live mobile. You can live anywhere, work anywhere or do whatever you want. Then any place you can imagine can be your backyard.

[ahibbert]

The term single axle means there is only one drive axle. Tandem axle means there are two Drive axles

[thjakits]

....interesting!

Those with hydraulic systems:
- do your systems have mechanical locks - once leveled? Or do you depend on the integrity of the hydraulic system?
- I assume the jacks are more like hydraulic pistons on heavy equipment, than bottle jacks? Telescoping or fixed-length?
- do your jacks swivel up for driving?


I love hydraulics and see it fairly easy to assemble a "manual" system to level a bus - use some bubble levels to get the inclinations right....
But it certainly would need a number of valves and solenoids....


Another option would be "Electric" - I found "Electric Cylinders" up to 20 tons....

thjakits

[ol trunt]

I went with a valve lock on each hydraulic ram. That allows me to extend each ram with just the force necessary for each ram to lift as necessary (up to 10k pounds ea) without disturbing the lift on other rams. As you can see in the pic, the pump also has a locking valve.
Jack
.

[thjakits]

....so - open all - pump until all sit on the ground - lock the shortest one - pump and see where it lifts - lock according to levels...

Where do you have the levels? I suppose close to the pump?

Use the hand pump instead of a gym membership?

thjakits

[thjakits]

delete----

[LargeMargeInBaja]

Quote:
"...one of my ideas is to install a four-point hydraulic-jack system so you can quickly level the bus at any campsite up to two feet of elevation differentiation..."
.
.
*** Caveat -- I know nothing about such ***
.
This came this morning in a newsletter (not called but should be) -- Clutter Your Factory RecreationVehicle With Expensive Complicated Sponsor Gadgets:
.
http://www.doityourselfrv.com/bigfoo...veling-system/
.
I did not read the press-release disguised as 'journalism' nor do I vouch for any point therein.
.
If you consider attempting this, I wish you well.

[LargeMargeInBaja]

Originally Posted by HamSkoolie

We are looking at putting four scissors on our frame. Each has a 7,500 pound capacity for a combined capacity of 30,000 pounds...

.
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.
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But I encourage you to go ahead fiddling with your contraptions... with my blessings.

[TJones]

I am using hydraulic landing gear off of some oil drilling trailers that went to scrap. The jacks use a counter balance valve which is connected directly to the extending port of the cylinder to lock the cylinders in place. They cannot retract unless pressure is applied to the retracting port of the valve. Also there is no hydraulic line that could fail between the valve and the cylinder.

The HWH brand leveling systems are set up to lift in pairs to prevent twisting of the frame. So lift would be either both front jacks, both rear, both left side or both right side. I plan a doing the same using some diverter valves to control which cylinders are activated. I will also use a flow dividing valve which provide equal flow to each cylinder regardless of the weight it is lifting. This will ensure that both cylinders will extend the same distance.

And yes I did have to cut holes in the floor of the bus to get enough ground clearance to mount them.

Ted

[JESUSBUS]

Originally Posted by TJones

I am using hydraulic landing gear off of some oil drilling trailers that went to scrap. The jacks use a counter balance valve which is connected directly to the extending port of the cylinder to lock the cylinders in place. They cannot retract unless pressure is applied to the retracting port of the valve. Also there is no hydraulic line that could fail between the valve and the cylinder.

The HWH brand leveling systems are set up to lift in pairs to prevent twisting of the frame. So lift would be either both front jacks, both rear, both left side or both right side. I plan a doing the same using some diverter valves to control which cylinders are activated. I will also use a flow dividing valve which provide equal flow to each cylinder regardless of the weight it is lifting. This will ensure that both cylinders will extend the same distance.

And yes I did have to cut holes in the floor of the bus to get enough ground clearance to mount them.

Ted

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?

[LargeMargeInBaja]

Originally Posted by JESUSBUS

...An overkill landing gear like...on commercial trailers...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?

.
a)
Anderson Brothers Heavy-truck Dismantlers in Eugene, Oregon.
I would be willing to bet they have a pile of semi-trailer landing-gear as scrap, waiting to be loaded in the forty-yard going to the smelter.
Each leg is probably rated 30k or better.
Two-speed crank-box would be my choice.
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b)
On a stroll through our local-owned family-operated Coastal Farm Ranch Supply, I saw 10k jacks engineered for 24k goose-neck flatbed trailers.
Weld-on, single-speed, manual crank -- about us$110 each.
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You are probably looking to stabilise the rig, or raise one axis an inch or two.
I think the 10k series are probably adequate, and they are new instead of out-of-service beat-to-death drug-all-over-the-lot-sideways semi gears.
.
Or, if you are anything like me, you install six or eight tens on a 30k rig.
Go twelves, just to be safe.

[thjakits]

Just for fun I googled...!

Just one that came up: https://www.powerpackerus.com/
this one has an endless number of applications - landing gears, stabilizers, outriggers, etc....!

I am sure they are not the only ones either...

I suggest to assemble "your system" and then go junk-yard diving, call disassemblers, used truck parts sellers, etc....

You should be able to assemble "your" system from used parts...

It doesn't have to be all extreme - what's the max incline/gradient you would dare to stop no anyway?? Figure that - a little trigonometry and you got your max lift needs...

I still would carry a few 4"or 5" hard-wood boards to get under the jacks - in case...

thjakits

[JESUSBUS]

Originally Posted by sportyrick

JESUSBUS: My thoughts are by the time you get done with a central pump, reservoir, hard lines, hoses, 4 valves, mounts that either swivel up or shorter stroke cylinders, pads on the ends of the cylinders, electrical lines to pump and valves, the whole kitten caboodle your looking at #1000.

I am not concerned about the weight. The bus has a diesel engine and the fuel economy does not change much with a variance of 1000 pounds. It's about efficiency in parking the vehicle and making camp quickly.

I want to take the bus to remote locations that aren't commercial camp sites.

Anyway, from what I have read, the best system would be to gather two landing gear from a semi trailer and use one hydraulic motor to drive all four cylinders through a shaft gear system. When I say best, I mean a combination of the cheapest components you can buy used integrated with modern technology. One landing gear on a trailer has a two speed gearbox that is hand cranked. Why not just attach a shaft with a bevel gearbox to the other one driven by a hydraulic motor?

[thjakits]

...if you can/want tot drive them all at once - HOW do you level the bus??
The gear-driven ones will lift the all the same at the same time!

The idea is to level the bus by raising the low sides.
I would suggest - with the simplest hydraulic system - as posted by Old Trunt, further up - you would have 4 valves open and pump until all legs are down - likely when you register the first movement of the bus.
Now you lock the shortest leg (the highest corner of the bus) and the leg on the same side of that one.
Next you pump on the remaining 2 legs until that axis is level (...you would have some fairly big levels installed near from where you control the whole show!).
Then you would close the nearest leg to the shortest one - open the diagonal one and pump again until that axis is level - lock all - done! I would guess all would happen in less than a minute...

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 system could fairly easily be made automatic or semi automatic with level-switches and electric-valves (solenoid valves) - doing it with "electric/mechanic" logic (and not with electronics) keeps it "mechanic interfere-able" (...in other words: If something breaks you can manually bypass and still use the system).
The solenoid-valves could of course be controlled with a electronic device too - e.g. a Bluetooth controller run by your cellphone. IF you have a cellphone with leveling capability - start the controller - put the cell flat on your table and press go!

thjakits

[JESUSBUS]

Originally Posted by ahibbert

The term single axle means there is only one drive axle. Tandem axle means there are two Drive axles

I guess it just depends on who you are talking with. Even a front wheel assembly is considered an axle or two axles depending on if it is an independent front suspension or a forged straight axle like they use on heavy trucks. I guess there is no standards on what you can call an axle. A spindle that a hub or rotor rides upon is considered an axle.

No hard feelings though!