On 2012-04-30, Larry Jaques wrote:
On Sun, 29 Apr 2012 20:07:30 -0500, Ignoramus25949
wrote:

I have a 12v hydraulic power unit similar to this one:

http://goo.gl/UpLJG

The application (what I am trying to accomplish) is to operate this
hydraulic beavertail semi trailer:

http://igor.chudov.com/tmp/Trailking/Trailking-0009.jpg

When OI think about using this pump, I become concerned that it is
operated by a starter-type 12v motor and is desighed for pick-up truck
liftgates or snowplows, that is, very intermittent duty.

Do the cylinders on your trailer use more than a gallon? You will
need a valve, extra hoses, heavy duty battery cable to the trailer,
and likely a larger reservoir, so this isn't as cheap as it seems.

True. Keep in mind though, that most cylinders there are double ended,
and those do not need a big reservoir.


This beavertail trailer, while also essentialy intermittent, takes a
lot more work per unit of operation (pull beavertail lock, pull
extension lock, raise tail, extend extension, lower tail). That would
take this little motor a long time and it may overheat and burn out.

Is my concern justified?

I have a few options for powering this trailer. I am basing this on my
assumption that all cylinders are double acting, so not a lot of fluid
is needed.

Oh, OK. Scratch the reservoir.


The options a

1) Install a truck wet kit. cost: $2,000.

2) Use a 12v hydraulic pump that I already have. Cost: Small $$ for
wiring.

3) Use a 115v, self contained power unit that I purchased yesterday
along with a hydraulic H-press for $195. I would take along a Honda
generator that we have to run this pump. Cost: $195, minus whatever $$$
I can get for the press without the hydraulic pump,and the four way
manual valve.

This is a 1.5 HP unit with a continuous duty Marathon motor.

The plus of number 3, as I see it, is that the 115v hydraulic power
unit there, is not intermittent duty, and could do the job, with less
financial risk than plopping down $2,000 on a real wet kit. It would
be slower to work the tail cylinders than the wet kit, due to less
horsepower, but it is not a big deal. It will, however, cost me extra $5
every time the tail is operated, to pay extra hourly salary tot he
operator.

I like #3 a lot, but what about a #4?

4) Mount a small gas engine and hyd pump with reservoir, creating a
local power unit usable anywhere? Cheaper than #3?

HF for the littlest Predator engine ($119), Burden Surplus for the
pump and valving ($250, 2spl DA), and maybe a tank, if you don't weld
up your own.
http://tinyurl.com/7pxq2y9 engine
http://www.surpluscenter.com/item.asp?Item=9-8239-L 15.5gpm pump (7x
faster than the 12v model)



Plus filters, belts, pulleys, mountings etc

In my experience, such projects end up very expensive and time
consuming. Plus I do not trust HF engines, but I do trust Honda.

And all those surplus things at these surplus centers have some fatal
flaws that make them somehow unusable for normal applications. (which
is why they ended up at those surplus centers, cannot be sold through
normal channels)

I am not trying to be difficult, just stating my past experience. Say,
this hydraulic pump's description says "pump to operate hydraulic
wheel motors on zero turn radius equipment applications including
turf, light construction and other mobile equipment". What exactly it
means, I am not sure, but it makes me slightly suspicious of whether
this is a general purpose pump.

i