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dr pepper
04-23-2010, 01:52 PM
I see a few have built presses from bottle jacks, I'm toying with the idea, but using a single upright and a outrigger for a table and another for the upper support.
I think it would be more professional to have the jack upside down, instead of the usual right way up with a guide beam and boss.
I've tried this and it doesnt work, obviously why folks use them the right way up, but I came accross this earlier, this bloke reckons if you add a resorvoir tank to a standard jack then you can use it upside down.

http://books.google.co.uk/books?id=eiUDAAAAMBAJ&pg=PA146&lpg=PA146&dq=make+an+arbor+press&source=bl&ots=mxRK2TKeT9&sig=7R4J4ND9t_wFSjJyt6fPymj3dh8&hl=en&ei=MsXRS-uEAounOOrTlPoN&sa=X&oi=book_result&ct=result&resnum=10&ved=0CB0Q6AEwCQ#v=onepage&q=make%20an%20arbor%20press&f=false

Has anyone tried this, does it work.

Black_Moons
04-23-2010, 02:40 PM
No, afaik most of those cheap jacks use ball valves for the one way valves.. and they are just gravity driven.

You CAN however buy 'any position' jacks that work in any orientation. But they cost more of course :)

If you must have an upside down jack, how about using a port-a-power style setup with a seperate pump and a standard hydrolic cylinder being used. Can even add one of those fancy PSI guages to see exactly how much force you are using.

knudsen
04-23-2010, 02:59 PM
Or just make it so the Jack is on top of the work and the bottom of the jack presses down on the work. The ones I've seen have the jack at the bottom, and the "table" moves up.

dr pepper
04-23-2010, 03:29 PM
Yeah come to think of it, I had one it bits it wouldnt lower and yeah there was ball bearings in it as valves, it was my engine lifter.
I wonder how the mush that made the referenced press got his to work, I wonder if some little biro pen springs would do the trick againt the balls, I can understnd the extra oil tank higher up, this will attempt to remove any air from the top of the jack which is where the pump would be if it was upside down.

I'm not going to the expense and complexity of a power pack and cylinder, a commercial press would be a lot cheaper.

Edit: done some more digging and found some answers on this site, some of you have allready done this, apparently one way to make the jack work the wrong way up is to fit a 'snorkel', so that the pump draws its oil supply from the 'top' of the jack rather than the bottom, alleviating the need for a top resorvoir.
Still not found any mention of the balls not working the other way up yet.

http://bbs.homeshopmachinist.net/showthread.php?t=28124&page=4

BadDog
04-23-2010, 05:08 PM
Or do it like my 50T. It uses a simple cylinder with remote pump/valve and reservoir. Perhaps the easiest way is to base on porta-power.

pistonskirt
04-23-2010, 05:11 PM
Essential modification principle explained both here

http://bbs.homeshopmachinist.net/showthread.php?t=14930&page=2

and here

http://www.practicalmachinist.com/vb/general/hydraulic-press-upgrade-200213/

Any specific questions not covered I would be happy to answer.

regards

Brian

dr pepper
04-23-2010, 05:45 PM
Thanks skirty.

So if I was to take my new 6 ton machine mart jack, weld a patch over the outer cylinder filler hole and drill a new one at whats going to be the top, then fitted the snorkel tube to the pump inlet and reverse the operating lever like yours, would this be all I need to do to make the thing work upside down?.
What about the valid remarks about the ball bearings used as valves, are they still going to work the other way up, you'd think theres a possibility of them falling to the other end of their housing and failing to work, or does the hydraulic pressure force the valves to operate correctly.

davidwdyer
04-23-2010, 07:47 PM
I once made a 10 ton press with a bottle jack upside down.

I just took it apart, found the hole which let in the oil, then press-fitted a copper tube from there to the top of the jack. Then I turned it upside down. It was pretty simple. I think I had to bleed the air out a little too.

Perhaps today I would have tapped and threaded the little tube.

The only drawback was that to use it, your pressure stroke of the handle was up instead of down.

Then I put a collar around the end of the cylinder with two "wings" which held springs. These springs then were attached to the top of the press for a return mechanism.

Real easy and worked well.

metalmagpie
04-23-2010, 08:09 PM
I don't believe there is a need to weld over the filler hole. After all, someday you may want to change the oil! Since the sheet metal body where the filler plug is isn't pressurized, it just has to hold in the oil. If it leaks, that's one thing. In that case, I'd drill/tap it for the next large size pipe plug and just plug it.

The best way to run a jack upside down is to tap the inlet hole. Many times a 1/4-28 tap will work in there. Get all the shavings out. Now thread one end of some 1/4" hydraulic tubing 1/4-28, put on some pipe dope, and thread it in tightly. That tube should be cut to length so it reaches nearly to the bottom of the inverted oil reservoir. Reassemble the oil reservoir and the jack should work fine upside down. If the spring return doesn't work upside down simply fabricate a yoke that fits over the piston, that pulls it back down with springs at both ends of the yoke. See the springs in this pic:

http://images.harborfreight.com/cpi/photos/97400-97499/97453.gif

metalmagpie

Racebrewer
04-23-2010, 09:15 PM
Hi,

I made one about 20 years ago and still use it.

Bought a 6 ton bottle jack from K-Mart. There was a rubber plug about half-way up the side which I pulled out. "Force threaded" a brass fitting into the hole and attached a clear vinyl hose up to a jack oil reservoir on the top of the jack. I worked all of the air out of the system and used it ever since.

Never thought about whether or not it would work......

I also removed the threaded extension piece, machined off the grooves, and threaded it back in, so that the surface that presses would be smoothand square, and not kick parts out.

I use mine for dis-assembling and re-assembling two stroke crankshafts and pressing wheel bearings. Used two steel plates about a foot square for the top and bottom. Threaded rod at each of the four corners for the vertical pieces. Two pieces of angle on the bottom to counteract the up and down pumping so it doesn't tip over.

On my jack the small external pump was mounted on the side. I put the pump handle in from what was originally the back side so the pumping force is still a downward push.

John

pistonskirt
04-24-2010, 05:56 AM
would this be all I need to do to make the thing work upside down?.
What about the valid remarks about the ball bearings used as valves, are they still going to work the other way


Possibly, depending upon the design of the none return & delivery system. Better quality types may already have the check ball helper springs, without which, even when used conventionaly, the jack may have a "soggy" action (especially when unloaded) which is exaggerated by lower temperature / higher oil viscosity. This is mostly caused by the unassisted check balls being slow to seat resulting in pump delivery volume loss.

In most cases when the jack is used upside down the pump suction / inlet port check valve will require the addition of a very light helper spring, probably much lighter than a biro pen spring & more like the carbon brush spring from a small electric motor. If too heavy a spring is fitted air may be drawn past the pump ram seals.
On the pump delivery side fitting return springs to the main ram will often serve the purpose of seating the delivery check valve, if however the main ram seals are tight enough to cause stiction a check valve helper spring may still be required to achieve crisp action. This spring would usually be slightly heavier than on the suction side.

There are a number of things that influence how easy or otherwise the conversion will be, including oil port design & orientation, quality of machining, seal quality etc.
Broadly speaking if the jack operates crisply when unloaded & normal side up there is a reasonable chance that it will work satisfactorily when upside down by just modifying the reservoir, adding the suction pipe & fitting ram return springs.

But broadly often speak with forked tongue :) ;)

regards

Brian

Barrington
04-24-2010, 05:17 PM
...but using a single upright and a outrigger for a table and another for the upper support.
So if I was to take my new 6 ton machine mart jack,..How deep a throat are you thinking of ? I would think 6 tons at a useful distance out is going to need a pretty serious structure ?

Cheers

.

dr pepper
04-25-2010, 02:48 AM
Thanks chaps.

The jack does work quite well the right way up theres no vibration or sticking, and when on its side with the pump on the lower position, so I will try the snorkel technique and see if it works, theres enough comments now to be worth giving it a try.

I was thinking of a throat depth of 10 maybe 12 inches, I have some 3 by 5 inch I beam which I might use, allthough I'm going to try and scrounge some C section from the breakers today, mabe something like 10 by 4 inch, do you think it'd hold if I triangulated the top and bottom.
Not sure whether to make the bottom rest moveable for differing length parts, I dont do axles or long items so might not need to.

Edit: Found this on eblag, believe it or not its rated at 10 ton, there isnt even any triangulation, looks like a couple of bits of c section and a bit of box reinforced on the lower side with a plate, anyways its the sort of thing I was thinking of, only floor standing.

http://i807.photobucket.com/albums/yy352/widgidibbie/press.jpg

dr pepper
04-28-2010, 04:11 AM
Hi again chaps,

I have started the build on the upside down bottle jack press, the frame is under construction, I'm still deciding whether to make the rest adjustable postion wise, the resulting weakening of the frame is the main concern.
Anyways I got the jack to work upside down with your advice, thanks chaps.

Heres what I did with the 'snorkel', yes that is 'stilly's' rash at the bottom of the inner cylinder:-

http://i807.photobucket.com/albums/yy352/widgidibbie/Picture341.jpg

gmatov
04-29-2010, 02:43 AM
Are you doing this JUST to prove you CAN? Jacks work quite well, base down, and have for years in home shop presses.

A hundred years of simplifying such items, and we get people who want to go round the globe to do it our own way.

Weld shut or seal in any other way the fill port, and the jack will not work properly. It is a vent. Without a vent to equalize pressure INSIDE the reservoir, and you will quit sucking oil to pump up the piston.

have fun,

George

BadDog
04-29-2010, 03:19 AM
Again, why not use a simple ram? You can get them in all sizes and strokes for very little money from surplus sails. These work in any orientation, and you have your option for power sources. Either hard line or flex line to tie in the pump. Select hand pump (or modify bottle jack base?) of appropriate capacity, add reservoir (if not already included), and you are in business. A power unit for a porta power would work, and you could still use the porta power. An air over hydraulic power unit would work, and could be used elsewhere. Mine has a 2 speed pump with rubber hose so the 50T ram can move side to side. One of these days I plan to modify with a stand alone air-over-hydraulic power pack, which I also want to use for a tubing bender and other purposes.

Another point I'll throw out is that a friend has a fantastically simple and convenient press he built from scratch. He's got an electric pump form some source, likely salvaged from scrap. And he has what amounts to a giant c-clamp built from salvaged heavy structural steel. The main body is from a piece of "H" (I think) about 14" x 8" x 1/2" wall. The than "boxed" it, and added some "strong back" outside gusseting with boxed inside gusseting at the corners. Big (similarly) heavy base, sorta looks like a fixed mill knee (no vert travel) with table from 2 pieces of 2" thick plate with rough milled square way sliding top. You can just slide them in/out to set the gap. And the cylinder is from a front end loader or the like. Ram is about 4" diameter, cylinder about 6-8" or so, with about 16" travel. And since it is not at typical closed frame, easy to get really big stuff into place, and seconds to press off with the power unit pendant. A smaller version would be very sweet, and while much heavier actually takes less space.

dr pepper
05-04-2010, 11:38 AM
Well its looking more complete.
I got another jack a 10 ton one, the press seems to take the load, close into the frame no problem, further out and there is a fair amount of give in the vertical section.
I intend to make the jack slide, so the jack can be positioned along the arbour, while using out past the reinforcing 45 degree section the smaller handle and a bit of care will have to be used, close in the full 10 ton.
(the jack in this photo is placed the 'right way up' for testing, I'm waiting for a long series drill to drill out for the 'snorkel tube', as I dont want to unscrew the main lifting cylinder, theres a steel ring seal under there).

http://i807.photobucket.com/albums/yy352/widgidibbie/Picture394.jpg