Thread: Workshop press build - hydraulic questions

Originally Posted by OxxAndBert

Thanks Shed. I've got a couple of PS pumps lying around I could play with...
What are you using for the control valve?

Steve

There are pipes heading in all directions on this press
If you want any more pics of it let me know..

Thanks Shed. Definitely a lot of good old fashioned using what was at hand went on with that build.

Steve

At the mine site I worked at for most of my working life, there were 3 presses that I can recall.
1. A 1 tonne arbor press in the auto sparks bay.
2. A 60 tonne Servex press with dual hand pumps, one high delivery and one for high pressure, like this one pictured below
3. Screen Shot 2020-09-20 at 9.02.06 pm.pngA 500 tonne horizontal press of unknown manufacture.
The Servex would have done most of the work, it was a great press and I would love to have one now, it was reiable and had enough capacity for most jobs we did, with lots of control. It had table adjustments about every 150mm, with a boat trailer winch to raise and lower it. The ram had a coarse square thread adjustment of about 150mm too so you could spin the pressure pad on the ram end down to take up the slack before pushing on the workpiece. Two heavy tension springs provided the return stroke. I think that a press like this one would be more than adequate for most work unless you were doing lots of big heavy bending or perhaps broaching big keyways all day, when an electric press might get your vote.


The 500 tonne horizontal wasn't used all that much but when we did need it, it was mostly used for pressing a 200 - 250 mm diameter shaft into or out of a 700mm diameter drum from an electric clutch (Magnetorque) from a P&H face shovel hoist drum geartrain as I remember. It had a ram of around 6-700mm diameter, and I don't recall it ever being defeated, although several times it was really groaning loudly before things started moving.

Hi.
I'm also somewhere in the middle of building a press....
After a lot of looking about, I decided to use the 1.5Hp hydraulic pump off a 7t electric wood splitter. Bunnings have them as do others. The price is very reasonable. We have had a 7t wood splitter for many years and it's been as reliable as my axe.... I've sheared the drive pin off a couple of times in that time - which was easy to replace - and better than breaking the pump castings.
These things have a 2-stage valve built in and their motor is operated with a push button. So it only runs when needed - keeps the noise and power wastage down.
Plumbing from its pump to my 30t cylinder will be straightforward, as is the intake from a separate container. The only minor challenge is that it is single action. So I will have to have a suitable spring return... I think that's acceptable on a hydraulic press anyway.

Thanks Ropetangler.
I recall using a very similar style one to that Servex early in my working life although I doubt the one I used was anywhere near 60T but too long ago to actually remember. We used it mainly for breaking beads on aircraft wheels and removal/fitting of the bearing cups.
The combination of the ram adjusting wheel and the dual pumps with their “stumpy handles” for quick hand held pumping made it really nice to use.
They are pretty popular and even the ancient ones still fetch serious dollars these days.

I’m looking at a similar size frame for mine.

Steve

I Have a press that was home made by an engenious gent. Two stage pump same as that seven he made all the check valves frame and cylinder himself. The only downfall is instead of using external return springs he put it in the cylinder and its just not strong enough to return the cylinder fast enough its glacially slow.

Its rated to 30t but I think the leather cylinder seals would fail.

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Originally Posted by OxxAndBert

Thanks Ropetangler.
I recall using a very similar style one to that Servex early in my working life although I doubt the one I used was anywhere near 60T but too long ago to actually remember. We used it mainly for breaking beads on aircraft wheels and removal/fitting of the bearing cups.
The combination of the ram adjusting wheel and the dual pumps with their “stumpy handles” for quick hand held pumping made it really nice to use.
They are pretty popular and even the ancient ones still fetch serious dollars these days.

I’m looking at a similar size frame for mine.

Steve

Yes Steve, pretty sure the they made a 30tonne version and perhaps a 15 tonner too. The 30 tonne was a spitting image of the 60 tonne version but just a little smaller I think. You are quite correct in your comments on old Servex prices, - I have yet to see a cheap one, usually $1700 and north of that, I have even seen one at over $6,000!

Steve you could use a logsplitter valve and 2 stage pump, they are fairly cheap and work ok
Here is a link to a scissor lift that i built that uses a 2 stage logspltter pump and valve.
https://metalworkforums.com/f65/t197...82#post1895682
They sell 50 ton logsplitters so those parts would be available at a reasonable price.
I think that to get more precise control with these valves you would need to put a second lever on
that has a low ratio that would operate the valve spool movement at opening
to enable fine control

Thanks Shed. That’s a nice scissor lift you’ve built there.

The log splitter bits sound like the way to go. I’m sure the quality isn’t as good as industrial gear but the price is right and not like it’s going to be running continuously for 8 hrs a day.

I think for a start I’ll use the low pressure pump and motor off the old bandsaw since I already have them, and they should be fine for positioning and light pressing work.
I should be able to scavenge most of the hoses etc off the old saw so just need to get a control valve as the saw is solenoid valve control.

I will definitely fit a hand pump which will give the higher pressure and finer control when I need them.

If I set it up with the idea of being able to swap in a different motor/pump at a later stage it should be pretty easy to do if need be.

I’ll need to make a tank as the bandsaw one is integral, but other than that I think I just need to find a hand pump.

Steve.

I just used the foot pump on my press to push a very rusty 32 mm shaft out of a 25mm disc, everything that was loose on the press table flew off when it cracked
It folds out of the way and you have both hands free, maybe it would be a worthwhile addition to fit this to the hand pump.

Is it a hydraulic foot pump or just a mechanical linkage to actuate the hand pump?

Steve

Originally Posted by OxxAndBert

Is it a hydraulic foot pump or just a mechanical linkage to actuate the hand pump?

Steve

It has a push rod to the pump, I wouldn't mind betting that the pump just has an o-ring for a piston/pressure seal, a couple of pics here.
I have included a comic of the cabling for you as i thought it might help, i took some pics if you want them let me know.
It incorporates a snatch block type setup to reduce the amount of effort to raise and lower the table, bit of weight there...

Great info - thanks Shed.

Steve

Originally Posted by jhovel

I decided to use the 1.5Hp hydraulic pump off a 7t electric wood splitter. Bunnings have them as do others.

This is kind of interesting, I'm not planning to make a log splitter (actually, that's a lie, I'm thinking about one to run off my Dingo at some point) but Bunnings are flogging a 5t log splitter for $329 which I interpret as a 240V motor and hydraulic pump plus a ram and some scrap steel for $329. It looks to have a relief pressure of 160 Bar, which isn't that great, but could be a handy 240V hydraulic power pack for some applications.

Please read the reviews of the Bunnings one before buying one!
Ours is like this one: https://www.klika.com.au/yukon-7-ton...iABEgIXaPD_BwE only $20 more....
But we paid a lot more for it many years ago....