Well, we decided to go a little differently than the other teams with our project. We are going make an on-board jacking system for a car. It is basically going to be an inverted floor jack with some type of removable extention so it will reach the ground.

The original plan was to run it off of the power steering pump (i'm not exactly sure how this would work, but the guy who is going to be doing most of this is a mechanic, so i guess he know's what he's saying..)

I suggested that we use an air system, an airbag like they use on the low riders and some helper springs, and the 3rd axel on some larger dump trucks. And to run it off an on-board compressor. Mechanic guy claims this will be too expensive (how much does an airspring cost??? anyone know where i can get one cheap??)

So basically, will the power steering pump out of an 89 302 crown vic be able to handle lifting itself off of the ground? What problems will we run into with this setup? If not, where do i get an air spring, and how much of a compressor is it going to take to get it to jack one half of the car off the ground??

In reality this is probably a pretty useless project, but hey, it'll be fun to tackle, and we might learn a thing or two in the process.

 

Should be able to lift the Eiffel tower with a power steering pump... and a big enough cylinder. PS pump should be at least 1000 PSI, so a 1" diameter cylinder should give you at least 3000# of lift.

To add, there are splitters for hydraulics that are installed at a single output and give you the ability to switch to one of two outputs. AFAIK, they are manual, at least the ones I've seen were but I'm sure someone's come up with electric ones.

YOu could reduce costs by installing the mounting point for the 'jack' and having some type of 'easy' quick release type setup and only one cylinder. A tapered reciever with a twist lock for the cylinder and quick release hoses at the 4 corners.

I don't see a problem with the hydraulic jack idea.

 

For simpleness (hydraulic systems are prone to leakage) - try an exhaust bag....

 

Just for clarity, my last post should be referring to a 2" diameter cylinder, not a 1" diameter.

 

YOu can get the front coil air bags from Summit for $60 a pair I think it is, the rears run about $300 for the setup, and you could maybe make a drop arm that lets the bags use leverage to push down... I see no reason air bags can't be done, since they hold up the loads on semi tractors, no spings on most of them any more (except front axle) just the air bags on the back axles. How about air shocks? Might even be something you can do there.

 

The 1936 Wolsley saloon had a hydraulic jacking system. There were four pistons with flat round base plates. To operate, you lifted the front passenger floor carpet and pivoted a metal plate in the floor to expose two of the controls , a selector for the front jacks or the rear jacks. You then closed the valve and placed an extension lever on to the pumping handle, down came the piston jacks and up went the car. When you opened the valve the jacks retracted, telescopic style up flush with the bottom of the chassis.

 

Netfly, I was thinking about doing something like that, but I don't think we have enough resources for 4 pumps and all the complications that comes with running 4 seperate pumps. (even if they are run in pairs.)

 

If your project is being graded on originality, I think it might get a low grade. Motorhomes have had automatic leveling jacks for years that is really only a jack on each corner. Open wheel race cars have had onboard jacks for years. Even Citreons (?) of the 60s had onboard jacks of sorts(you could raise the entire car for ground clearance and you would simply raise the car, put a block under the corner that needs to stay raised and then lower the car. If I need to jack up my John Deere to take a tire off, I simply raise it hydraulically with the blade that is powered by the hydraulic pump that operates the lift, power stering and hydrostatic transmission. My travel trailer has an electric tongue jack that works on 12 volts and will lift up to 3,500 lbs.

 

Just thought the reference might give you some insight that would help. I think you’re on the right track using hydraulics, though the air system may end up costing less. I have a convertible top system out of an old 60’s Mustang and it’s surprising how powerful the little electric/hydraulic pump and cylinders are. Are you trying to lift one corner or all 4 at once?

 

One side of the car at once.

 

A little off-topic, I wish we got to do something cool like that in our engineering class. We're making sounds on the computer at the moment.

oh.........so.......exciting..............

 

haha. Yeahh, we're drawing lines in AutoCad. whoopeee!

The professor doesn't seem to care about much at all though, he just told us to make something and that was it. Doesn't seem like its worth the 4 credits at the moment, we'll see.

 

I'm curious why you want to lift the whole side of the car instead of a corner. Seems impractical if this is for changing tires as typically only one tire is flat at one time and usually only carry one spare.

 

Just for simplicity... less parts, less lines, less weight, less stuff to go wrong.

 

you could always go the hydro route http://www.truelowriders.com/50Playa...hydraulics.asp