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Re: 2 vs 4 post lifts

To: "Mark Andy" <mark@sccaprepared.com>
Subject: Re: 2 vs 4 post lifts
From: "David Scheidt" <dmscheidt@gmail.com>
Date: Fri, 2 Feb 2007 11:00:10 -0500
On 2/2/07, Mark Andy <mark@sccaprepared.com> wrote:
>
> Howdy,
>
> On Fri, 2 Feb 2007, David Scheidt wrote:
> > A two-post in-ground lift is a two post lift, in the ground. So instead
> > of having arms travel on above ground posts, the posts are hydraulic
> > cylinders. See
> > 
>http://www.rotarylift.com/products/Product_Detail/Product_Detail.asp?PN=Inground%20SmartLifts%AE&CAT=Professional%20Automotive%20Service
> > for some pictures. When the lift is lowered, you've only got the arms
> > in the way. Never any worries about hitting the lift with a car door.
> > No limits on the height of the vehicle you can lift with one, since
> > there's no top bar.
>
> Now _that_ is slick. How much? What sorta concrete / site prep is
> required?

Site prep depends on local soil conditions.  You need a hole that's
about ten feet deep.  If your soil is too wet, or isn't strong enough,
it'll have to be fixed.  The bottom of the hole is filled with gravel,
the structure is installed, most of the hole is back filled, and the
top foot or so is filled with concrete.  Modern in-ground lifts put
the whole works in a plastic tub, that keeps the lift contained in the
event of an oil leak.

New inground lifts are mostly high pressure/low-volume hydraulic
systems, driven by an electric pump.  Old ones were low pressure,
driven by  air-pressure.  There's a huge amount of oil to leak in
those systems (75 gallons per, or so.), which is one of the things
that drove the rise of above-ground lifts.

Cost is something like twice that of above ground lifts.  That's
including installation costs, I don't know how much is the cost of the
lift itself.  One big advantages of inground lifts is that they take
less floor space.  With out the posts to get in the way, you can
install them closer together, or in a smaller bay, or in an odd spot.
A shop I used to work in had five in ground lifts, in a building that
had four bay doors, two in front, two in back.  The fifth lift was in
the center.  It didn't get used a whole lot, because it was a pain to
get a car on and off, but it was otherwise empty floor space, and it
was very nice for cars that were going to be there a while.  We could
put a car on it, remove the transmission, send it off to a rebuilder,
and leave the car on the lift.
If they'd had above-ground lifts, they'd never been able to put a lift there.
-- 
David Scheidt
dmscheidt@gmail.com




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