Grassroots Air Jacks

I suppose I need a basic understanding on how the things work foremost (I.E. how much air pressure is typically used, is it a simple piston and rod, etc.). Short of spending a ton of cash on one of the already available systems, what are the thoughts concerning home-brew air jacks. I have several thoughts, but none really seam feasible as far as space is concerned. Furthermore, I don't plan to build something I'd trust my life with by crawling under the car, just something to raise the car to quickly change a wheel.

Not sure why you think an air jack would be better than a regular jack for changing tires.

Most interesting air jack thingie is the big bladder type you connect to the tailpipe. It's for jacking cars to change the tire.

I, too, have been thinking about some sort of pnuematic jack built into the car. My cars are low and the floor jack is cumbersome in this situation. I don't think its really practical in the big scheme of things but for tire changes and oil changes in the garage, with the car supported by jackstands, it might save some time and space. Space, meaning rolling the floor jack around in tight spaces (may garage!)

Here's a cheap option for you:

17mm nut welded to a scissor jack. Slip under the car, hit it with the impact and the car levitates. My car has 17mm lug nuts, so I don't even have to chance the socket on the jacket. Not as cool as air jacks, but cheap and easy.

Hey, I like it!

I'd probably start by looking up air cylinders in a McMaster-Carr catalog and see if there's one with the right length of travel that would fit. Then put some sort of quick-connect nozzle on it.

Methinks he likes the watching the pit graphics on GT4.

Keith wrote: Here's a cheap option for you: 17mm nut welded to a scissor jack. Slip under the car, hit it with the impact and the car levitates. My car has 17mm lug nuts, so I don't even have to chance the socket on the jacket. Not as cool as air jacks, but cheap and easy.

My car has 19mm lug nuts. And the factory spare tire jack has a 19mm lug on it. No mods needed

You'll need a pretty big cylinder to lift, say 1000#, with 100-125 psi. I'm sure you can boost your operating pressure with a multiple stage compressor or something or that sort, but none of this sounds grassroots to me. If you want cheap, you're better off going hydraulic. High pressure hydraulics are cheap and easily to source.

If you're doing what I think you're doing, 4 of keith's setups welded to the underside of the car might get the same effect for cheap and still relatively quick. For real pimipitude - run a rod connecting the right and left jacks so that one entire end lifts up with a single round of impacts.

Looking at air jacks avaialble on the internet, I would say that a junkyard that deals with large trucks would allow you to source some air suspension parts to build something on your own. The only cars that I am familiar with that had factory air suspensions are 80's Lincolns, and I have never seen one that is still functioning, so I doubt you can use any parts from those.

Another option is the airbag-style, also know as a lift bag. Rescue crews use them, but I bet a heavy-duty truck tire inner tube would work in a pinch. Still not easier than a manual floor jack, but it would get the car off the ground.

What about using a CO2 tank or similar for higher pressures? I've never really thought about it, but you'd need a fair bit of throw to get good ground clearance while retracted and still be able to lift enough to unload the suspension enough to get the tires off the ground.

Bryce

DILYSI Dave wrote: If you're doing what I think you're doing, 4 of keith's setups welded to the underside of the car might get the same effect for cheap and still relatively quick. For real pimipitude - run a rod connecting the right and left jacks so that one entire end lifts up with a single round of impacts.

Yes, the plan falls into the devious realm, if you will. I sorta like that Idea.

I'll keep digging, I've got a little while before it needs to work. Exhaust filled bags and floor jacks just ain't gonna cut it.

uh oh...i'm sensing some LeMons pit strategy here

What about a system based on what stuntmen use to roll cars over. It is basically an air tank connected to a barrel with a 4x4 in it. If you could get a round piston to seal in the barrel, with a pressure release valve, and a CO2 Fire Extenguisher, you could maybe build a jack... or shoot 4x4s at other drivers.

You're going to have a tough time finding a cylinder to do what you're asking. Most any cylinder that will fit under your car with enough stroke to lift it off the ground will buckle with the load.

What's your budget?

Tommy Suddard wrote: What about a system based on what stuntmen use to roll cars over. It is basically an air tank connected to a barrel with a 4x4 in it. If you could get a round piston to seal in the barrel, with a pressure release valve, and a CO2 Fire Extenguisher, you could maybe build a jack... or shoot 4x4s at other drivers.

I like it, Starting monday I will be firing 4x4s at people.

Keith wrote: Here's a cheap option for you:

some rver's weld this type of jack to the frame of their rv's as manual stabilizers. works great and can lift the rv off the ground if done properly. don't see why that wouldn't work on a car if one could get around the clearance issues ofcourse...

If you do go through with this, please build some safety factor into the system. If you're just using it to change tires in the pits, I see no problem. But if you're getting under the car, and an air leak = car on your chest, I'd look into some sort of latching system.

+1 for Keith's idea. It's the cheapest and all mechanical (so safe).