Went to TMI yesterday to find some leveling jacks. JOST makes a nice one, has a 10x10 fixed foot and is just under 30" tall with 17" of travel for $290. They also make a 19" version. I'm thinking they may just be able to bolt directly to the bay bulkheads. I'm thinking one 17" centered in the front and two 19's in the corners of the rear bay. Thoughts?
Jim
Here are the rear jacks in place but not bolted up. I think they will work fine.
The one on the bench has the cushion foot removed so I can install it in the front. I think I can use bolts to reattach it instead of welding. The last shot is of a gearbox I am going to try, it has about a 100:1 ratio. I have a 1/2hp 110v motor that will bolt to it. It draws about 780 watts so one of my 900 watt inverters should power it OK.
Incidentally, the bay floors of these is aluminum, not stainless.
Jim
These are obviously mechanical jacks and not hydraulic.. I'm assuming they will be powered by three separate motors and controlled individually..>>>Dan
( Very similar to jacks found on a 5th wheel.)
Huggy has 4 hydraulic jack 2 brhind the front wheels and 2 behind the rear.
I was afraid of the 3 i thought the one in front might rock when getting in and out.
been that way for close to 20 years still works good.
uncle ned
Here are some more shots. After studying the problem of mounting and looking at material costs I've decided that a truss type mount makes the most sense and I'm leaning towards a build up using 1/4" x 1 and 2" strap and a bit of 1 x 2" rectangular tubing.
As you can see from the last shot the bottom will have to be reinforced where the jack went through the center rub rail but that should be no real challenge. The load should be balanced fairly evenly between the 3 legs with perhaps a bit more on the rear. If you've never owned a tripod rig you can take it from me that they are easy to level and stable. The extra width between the rear jacks will insure that. As far as tipping it when you climb aboard? Ha! Don't make me laugh.
Jim
I have the three leg system in my rig,, one in front and two at the rear.. The principal of the three legged system is to raise the front first to allow the frame to "teeter" when leveling laterally,, this prevents frame twisting and minimizes body flexing when leveling on off camber surfaces..>>>Dan
Jim
This looks cool to me.
I'm not sure about your bus but I was drilling into the back bulkhead during my construction. It was more inboard than where your pictures show but I found an air beam back there. It hissed away while I was swearing. When it was done the suspension was down. I got to make the hole bigger so I could weld up my mistake. I'm sure you are ok where you are locating them but thought I would share.
John
It's my understanding that bus air suspensions are actually a tripod system: one leveling sensor for each side of the rear, and one leveling sensor for the front, with both sides of the front plumbed together.
I expect any solid connection to the ground would be welcome. Just make sure all jack feet are placed on a wide solid footing or they will sink.
Quote from: hogi6123 on September 19, 2020, 05:23:58 PM
It's my understanding that bus air suspensions are actually a tripod system: one leveling sensor for each side of the rear, and one leveling sensor for the front, with both sides of the front plumbed together.
I expect any solid connection to the ground would be welcome. Just make sure all jack feet are placed on a wide solid footing or they will sink.
Yes and no. There are only three height valves, but there are wheels at all four corners.
The two rear valves control the side-to-side height adjustment, and the front valve control the up/down of the nose. But, the front does not have a separate side-to-side control from the rear.
The newer stuff has leveling valves on each corner ,I have the 3 point leveling system on the Trek,the 4 point system on the CC is a lot more stable so was the 4 point system on my Eagle
Quote from: luvrbus on September 20, 2020, 06:12:05 AM
The newer stuff has leveling valves on each corner ,I have the 3 point leveling system on the Trek,the 4 point system on the CC is a lot more stable so was the 4 point system on my Eagle
Majority of the 4 leg systems are designed to prevent you from twisting. Some of them have both front jacks tied together so that they cannot be operated independantly. Most 4 legged systems are designed so that 2 jacks are always operating in unison, never opposing corners. My air levelling system actually senses twist and will shut the system down if a preset twist limit is reached.
Quote from: thomasinnv on September 20, 2020, 08:48:27 AM
Majority of the 4 leg systems are designed to prevent you from twisting. Some of them have both front jacks tied together so that they cannot be operated independantly. Most 4 legged systems are designed so that 2 jacks are always operating in unison, never opposing corners. My air levelling system actually senses twist and will shut the system down if a preset twist limit is reached.
My HWH Active Air system if the excessive slope light is on it won't even work manually or automatic
I don't think there is any air in the bogies on the 102D series but please correct me if I am wrong. I plan to tie into that part of the framework with a truss that runs across the bulkhead in the rear and one that runs between the front frame members in the front. I should probably plan on using a thread locker anyway and that should seal up any leaks.
Right now I'm preparing my steel order, currently including 3 lengths of 1 x 2 x 3/16 rectangular tube, one 1/4 x 2" strap, one 1/4 x 1" strap, one 1/2 x 1" strap (only need 2 ft but it's handy to have around) and 6ft of 1 x 1 bar.
The rear truss will have three 1 x 2 stringers and the 2" strap full width plus another 1 x 2 across the bottom, the front will have two stringers plus the bottom, both with diagonal bracing via 1" strap. That should be quite stout enough even for the cantilevered load. The bottom of the jack will be tied into the bay floor, at the strong outside corners at the rear and at the floor stringer in front. Btw, the fresh air duct is a 3" flue pipe that runs through the left side of the front bogie frame, that's what the 1/2" strap is for, to build a riser to move the the fiberglass 90 degree duct to the rear where it directs the air up into the return duct.
Incidentally while under the bus I discovered it had been high centered at some point in it's life (almost inexcusable with the rear-lift) and this was why my condenser door was jammed up. I used a high lift jack and a bracing bar to push the outer rail back down so the door would close easier. Still not perfect but much closer and I can probably get it back to normal from here.
I will be making use of the dump valve to lower the front before leveling, and looking to see if there is a valve that can also work that way in the rear. I will add valves there if I have to for that purpose. That way I'll be able to drop it onto the bump stops before leveling which has two benefits. First it makes that first step into the RV much more manageable, and second and every bit as important, because the ride system will air up before rolling out it will lift the leveling jacks off the ground.
I'm not saying it's acceptable practice to drive it that way, just that it makes a good safety measure to be sure the jacks don't get damaged in a drive away, which we've all seen. A walkaround should be part of every departure but anyone can make a mistake.
So does anyone know offhand if the valve(s) that return the rear-lift to standard ride height can be used as dump valves? (or did they just use the standard leveling valves to do it? ...probably)
Finally, because the door is air operated I should have air and power available to operate that whenever possible but I do not need air to anything besides the door that I know of. So which tank provides air to the door? What else does that tank supply, and is it isolated by a check valve? In other words can I relocate my compressor to the front and just air up that tank, or will I have to re-plumb the door supply?
Unfortunately the online manual is incomplete and the air and wiring diagrams have been cut short making them near useless.
Jim
Jim, on the D series the tag axle air bags are tied in with the drive axle. 2 bags on the tag axle, 4 bags on the drive axle...the drive to tag axle weight distribution is 2:1. The tag axle is not "directly" connected in the sense that it has a series of control valves for tag axle unloading, but under normal driving conditions it is essentially one single air system for each side, right and left rear.
Quote from: luvrbus on September 20, 2020, 09:12:31 AM
My HWH Active Air system if the excessive slope light is on it won't even work manually or automatic
Not even if you power down and then power back up in manual mode?
On my system it will still work in auto or manual with excess slope light on, it just obviously won't achieve level, the auto will time out after a few minutes. The excess frame twist sensors however cannot be over ridden in any mode but I can't see where that would be a good idea anyway. Don't need windshields popping out.
I think that's one advantage of the tripod setup, you never have to worry about frame twist as long as you run down the front jack first. The only limits I'll have on this system is maybe a switch for the full up position and at least initially it'll be full manual.
Actually to begin with I'll crank them manually until I get the gearmotor sorted out. I have one I can fit up to test that has a 1/2 hp motor and 100:1 gearbox and see how that works. Depending on the results I can then decide what to order.
Jim
Quote from: thomasinnv on September 20, 2020, 11:31:40 AM
Not even if you power down and then power back up in manual mode?
On my system it will still work in auto or manual with excess slope light on, it just obviously won't achieve level, the auto will time out after a few minutes. The excess frame twist sensors however cannot be over ridden in any mode but I can't see where that would be a good idea anyway. Don't need windshields popping out.
Nope the Active Air controls the suspension too not just the leveling, a nice system but will cost a fortune to repair or replace when the time comes I bet
Quote from: richard5933 on September 20, 2020, 04:22:10 AM
Yes and no. There are only three height valves, but there are wheels at all four corners.
The two rear valves control the side-to-side height adjustment, and the front valve control the up/down of the nose. But, the front does not have a separate side-to-side control from the rear.
That sounds like what I was trying to describe. The air diagram (for the mc-9) shows the front leveling valve output teed to both left and right air bags. That would mean the air transfers between the front left and right bags depending on ground contour and rear axle roll. The net effect is to act like a tripod.
Quote from: luvrbus on September 20, 2020, 04:22:24 PM
Nope the Active Air controls the suspension too not just the leveling, a nice system but will cost a fortune to repair or replace when the time comes I bet
Cliff if you ever end up looking in the face of a major repair on that system you might consider Valid Manufacturing, they are in BC Canada. I purchased my complete system from them and installed it myself. They were about 1/3 the cost of the HWH system. FYI, the first powergear air levelling systems were actually Valid MFG with powergears name on it. They been in the business for a long time.
Quote from: thomasinnv on September 21, 2020, 08:21:54 AM
Cliff if you ever end up looking in the face of a major repair on that system you might consider Valid Manufacturing, they are in BC Canada. I purchased my complete system from them and installed it myself. They were about 1/3 the cost of the HWH system. FYI, the first powergear air levelling systems were actually Valid MFG with powergears name on it. They been in the business for a long time.
I read on the Country Coach forum folks having Active Air installed on older models coaches was costing them $10,000.00 plus at the HWH factory,I have a spare Active Air I bought for my MCI D from the sale at CC wasn't that pricey ($750.00) if it's all there
$750 would be a heck of a bargain. I spent about $925 on the three landing gear and will probably spend more than that on the gearmotors to drive them. (Note however that I got exactly what I wanted and brand new as opposed to what you might find as used or surplus parts.) The steel for the mounts is likely to cost over $250, and then there is the controls and the wiring plus all the fabrication. So realistically, doing a system like this yourself it can be done for somewhere between $2k and $3k which is really very reasonable for what you get and should be an extremely reliable and dependable system. $10k sounds like an awful lot, but for that money you are getting a well engineered and proven system with sophisticated electronic controls fully installed, right? No thinking involved, just write a check. The cost of that kind of convenience is not insignificant.
I do like the serenity of never having to think about hydraulics or air. But there is another hidden cost: Either the expense of DC gearmotors to drive the jacks or inverters to drive AC motors. Happily I have a surplus of 900 watt inverters which will work fine as long as I stay under 1/2hp on the motors. There is some switching required which will mean additional hardware. One option is to use 3 phase motors which tend to be cheap and available along with VFD controllers which can be had for about $50 each these days and those generally have external inputs for direction and speed, as well as the ability to overdrive for rapid extension and retraction. Well the cost of relays to do the job wouldn't be much less than that and much less versatile. So for me that's a very realistic option. Otherwise I'd be pounding the bushes to find suitable DC motors and relays.
Jim
I don't have my paperwork in front of me but I believe my Valid system was somewhere around 3k delivered to my door. Came with everything needed, all cabling and sensors, valve manifolds, auxiliary compressor with tank, even had all the airlines and fittings. The system retains the factory levelling valves setup for use while motivating.
No doubt that's a good system. It sounds about like what I was working towards before I decided to go with the landing gear.
But I've never been particularly lucky with air systems. My shop air always leaks down, for instance and it's a constant ordeal to find and fix the leaks. My air suspension I designed for my sports car is the same. It regularly develops some small leak somewhere that takes days or months to find. As complex as the bus air system is, why should it be any different? So I went back to that basic question: For a system that absolutely has to stay in a fixed position for days or weeks at a time why would I want to depend on a fluid, either air or hydraulic, that can leak out? The answer obviously enough was that I should not. And I've had long experience with hydraulics as well, and yes when they are new they generally don't leak down. Generally. They are expensive and difficult when they do, and it isn't a question of if, it's a question of when. I expect this bus to last 30 years. I don't need to be installing systems that I know will have to be rebuilt.
So a mechanical system it is. And of all the jacks available the landing gear just immediately made sense. It's designed for a very similar application. It's overbuilt. It's affordable. It comes with an omnidirectional cushioned pad. It has a 10 x10" foot. It has surplus travel. It's easily mounted, and it's electrically controlled or can be manually operated. Replacements are available everywhere. Honestly if it wasn't for the convenience factor I would certainly consider simple manual operation and may do that anyway at least short term. After all, semi drivers have no problem with them. A simple angle bracket made of heavy angle iron is all that is really required to mount them and that would point the shaft towards the side of the bus where you could have a socket to accept the handle. I'm not doing mine that way for several reasons but it'd be the cheap and solid option.
Jim
If i needed to level more than using my air bags. (seperate valve for each one), i made a set of short ramps using 4x4s bolted together.....used to level the bus, change a tire, never wore out, never broke, total cost about 20 bucks. ;D
What Ed said
Quote from: Jim Blackwood on September 21, 2020, 10:05:45 AM
So a mechanical system it is. And of all the jacks available the landing gear just immediately made sense. It's designed for a very similar application. It's overbuilt. It's affordable. It comes with an omnidirectional cushioned pad. It has a 10 x10" foot. It has surplus travel. It's easily mounted, and it's electrically controlled or can be manually operated. Replacements are available everywhere. Honestly if it wasn't for the convenience factor I would certainly consider simple manual operation and may do that anyway at least short term. After all, semi drivers have no problem with them. A simple angle bracket made of heavy angle iron is all that is really required to mount them and that would point the shaft towards the side of the bus where you could have a socket to accept the handle. I'm not doing mine that way for several reasons but it'd be the cheap and solid option.
Jim
For several years I've been thinking of doing what you're now doing, the only difference being that I would have each jack's crank handle shaft extend out to the side of the bus, and then all I need do is use a powerful cordless drill to wind it down to the ground, then finish the jacking by hand if the drill won't handle it. My home-made spare tire winch is already like this - a cheapo Harbor Fright worm-drive 2000lb winch lowers the spare wheel/tire to the ground or lifts it back up to its cradle, and I can take the crank handle off it and use my cordless drill instead. Easy! I definitely like the KISS approach - heck, I don't even have airbags, and my bus rides and handles really well without them.
John
John, to do it the way you describe, all you need is a few 11" long chunks of big angle iron with one 9" leg and the other 4" or so, probably 1/4 to 3/8" wall would be fine. In the rear you'd need a 1" spacer between the bogie and the bulkhead. Bolt that to the bogie, bolt the jack to that, and there you go. Chances are pretty good for finding such angles at a metals scrapyard. (Might be thicker but so what?)
In the front for a 4 leg it'd be about the same but except for the spacers you have to work around the fresh air duct. For a 3 leg you have to bridge between the 2 rear legs of the bogie.
In all cases the shaft now faces the side of the bus and can be extended as desired and exit beside the bay door.
Jim
Actually I think those spacers need to be 1-1/8"
Jim
🙃
Here is the first install shot of the forward jack.Unfortunately it turns out the rear legs of the bogies are not fully boxed. That means it has to come back out for more welding and angles will have to be attached to the sides of the bogies for the truss to bolt into. Easiest might be the outboard sides but if the walls are thin, say under 3/8" then it will make more sense to drill through both sides and put the angles inboard. I'll know more after I make up the angles and drill the first pilot hole. That pushes me back a week or so.
This problem will not come up at the rear as the construction is different.
Jim
The rear legs of the bogies turned out to be only around 1/8" thick, maybe a bit more. So I cut some 3/16 x 2" angle iron to attach vertically to tie in the truss. It has to go on the outside since there is a panel between the rails. I have a couple of options here. I've ordered a nutsert tool that handles up to 1/2-13 nutserts and will use those in the bulkhead panel, then to attach the angles to the bogie legs I can use more nutserts and/or mig weld. Sort of leaning towards the belt and suspenders approach since the material is a bit on the thin side.
Jim
Jim - what exactly are we looking at here? Hard to tell without a photo from a bit further away. Is that a single unit in the center of the front?
the wiring chase overhead would indicate front center strut. although not centered but offset is to heavy side? ft.
Yes, it is centered in the bus. No offset at all but the photo and the asymetrical truss may make it look like there is. The asymetry is due to the fresh air duct on the left but the length of the truss legs is equal on both sides. What you are looking at is the forward bulkhead of the front bay. and the large holes in the truss ends are centered on the downlegs of the front suspension subframe.
Now there isn't enough structure there to fully support the weight of the bus with the jack so I need to add reinforcement on the front side of the bulkhead.
Jim