Hydraulic hand-pump, pressure-gauge and jack / cylinder - buy

Hello again all
I need to get advice. I need a portable hydraulic pump & cylinder combination - hand pump - oil pressure gauge
- hydraulic cylinder(s)
because
* blowing someone else's hydraulic seals makes you "persona less grata"
* the fillet weld tests break abruptly, which is cruel to repeatedly do to someone's "shop" press
so, as I can see a lot more tests to do - plus other applications for a hydraulic jack - I need to get my own kit.
The oil pressure gauge is to give a "Force=pressure*area" estimate of Force being applied in the tests. Plus other uses. eg. you could be tensioning bolts.
I've done calculations, and in view of experience I have, this is the "bottom line" - the biggest cylinder needed v 50Tonne cylinder with 50mm stroke.
Any good advice?
Rich Smith
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"Richard Smith" wrote in message
Hello again all
I need to get advice. I need a portable hydraulic pump & cylinder combination - hand pump - oil pressure gauge - hydraulic cylinder(s)
because
* blowing someone else's hydraulic seals makes you "persona less grata"
* the fillet weld tests break abruptly, which is cruel to repeatedly do to someone's "shop" press
so, as I can see a lot more tests to do - plus other applications for a hydraulic jack - I need to get my own kit.
The oil pressure gauge is to give a "Force=pressure*area" estimate of Force being applied in the tests. Plus other uses. eg. you could be tensioning bolts.
I've done calculations, and in view of experience I have, this is the "bottom line" - the biggest cylinder needed v 50Tonne cylinder with 50mm stroke.
Any good advice?
Rich Smith
======================================I think the best answer is to acquaint yourself with local small hydraulics shops and ask them. Several of the owners were happy to find another creative tinkerer and showed me all the stuff they'd designed and built.
A hydraulic press is a particularly easy machine to build or modify if you have the means to cut and drill structural steel. I'd record the dimensions of the channels and bolts of the 50 ton press you used and look for cutoffs from a steel fabricator.
Hand pumps can be found in real or fake Porta-Power kits and Greenlee punches, however I haven't seen 2-speed hand pumps except on 50 ton presses and manual log splitters. Powered log splitters do have 2-speed gear pumps, actually separate wide and narrow gear pairs. A valve bypasses the wide pair at high pressure.
Do you have British suppliers like these where much of my hydraulic kit came from? https://www.northerntool.com/
https://www.baileyhydraulics.com/
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Hiya.
I've already learned a lot of useful things from looking at those suppliers. I don't think there's anything quite like "Princess Auto" which I saw in Canada.
Locally we have a hydraulics supplier - met them doing runs for boat's hydraulic steering gear. https://www.dereklane.co.uk Derek Lane & Co on the Heathfield trading estate near Newton Abbot, here in Devon. I've called by. To an extent, that's why I'm asking here. What should I be asking them for? They have a lot of stuff, and many big industrial customers, so I need to have a good idea and and get very close to the final solution - within reach of them being able to suggest detailed optimisation.
There are bigger "lifting gear suppliers" used to online trading which I can also reach to.
Regards, Rich Smith
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I haven't tried it yet, but I wouldn't use a press. Would get a beam about 3m long and use that as the "base" / "frame" / "chassis"
Either add a "bridge" / "hoop" transversely in the middle to put the cylinder under it, with the sample on bearers - or fasten down the beam ends and put the cylinder directly on the beam pushing up on the sample.
Advantage is, as welds get bigger, eg 12mm (1/2inch) leg-length with over 80 tonnes-force breaking, can keep forces down by having longer sample.
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"Richard Smith" wrote in message
I haven't tried it yet, but I wouldn't use a press. Would get a beam about 3m long and use that as the "base" / "frame" / "chassis"
Either add a "bridge" / "hoop" transversely in the middle to put the cylinder under it, with the sample on bearers - or fasten down the beam ends and put the cylinder directly on the beam pushing up on the sample.
Advantage is, as welds get bigger, eg 12mm (1/2inch) leg-length with over 80 tonnes-force breaking, can keep forces down by having longer sample.
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I built a non-standard hydraulic press on a single wide flange beam too, arranged like a log splitter instead of a crossbow. It soon became clear that it lacked the versatility of the standard design's wide range of height adjustment and gap between the channels to pass a shaft, for instance to press a gear on/off a distributor, to help out a scrap dealer friend.
Here is an A-frame design somewhat similar to yours. The flexible tension linkage doesn't entirely prevent the jack from shifting sideways so it needs the separate guided push rod. https://www.harborfreight.com/6-ton-a-frame-bench-shop-press-1666.html
I bought one and swapped the short parallel side angle irons for much longer ones, since I make axles and power transmission shafts.
Crankshaft main bearing caps are useful as the bars that support the work. I broke up and melted an aluminium engine block for casting alloy. Molten aluminium forms interesting shapes when poured into a snowbank. Molten glass does this: https://en.wikipedia.org/wiki/Prince_Rupert%27s_drop
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On Thu, 24 Dec 2020 18:27:06 -0500, "Jim Wilkins"

Also known as Czar's Tears.
Joe Gwinn
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On 25/12/2020 20:00, Joe Gwinn wrote:

I'm not sure I'd do it again but as a amateur glass blower a glassblower I knew who had experienced it before convinced to have one go off in my hand, no damage just felt like I'd been high fived by the terminator.
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Here's what I've got
http://www.weldsmith.co.uk/tech/tech_imgs_misc/210210_hyd_pumpgaugecyl_1.jpg
http://www.weldsmith.co.uk/tech/tech_imgs_misc/210210_hyd_pumpgaugecyl_2.jpg
Hydraulics: * single-stage 700Bar pump * 4inch/100mm gauge to 700Bar * 3m hose * 20Tonne cylinder with 44mm stroke
I worked-out 20 Tonnes-force would be "the Goldilocks quantity" (just right) with this for-purpose testing rig http://www.weldsmith.co.uk/tech/struct/210122_fwtest_rig/210122_fwtest_testrig.html "Tensile-test rig for beam-configuration fillet-weld samples"
I went to a local supplier.
They also got me a piston seal for the Co.'s 10T cylinder which started leaking when I was using it, and it works perfectly again when I fitted it - "persona grata" and it's seen in the test rig pic.
I've been using Co's cylinders and pump for a number of steel fabricating jobs - got going on this as a line of knowledge.
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"Richard Smith" wrote in message
Here's what I've got
http://www.weldsmith.co.uk/tech/tech_imgs_misc/210210_hyd_pumpgaugecyl_1.jpg
http://www.weldsmith.co.uk/tech/tech_imgs_misc/210210_hyd_pumpgaugecyl_2.jpg
----------------------
Nice work! I hope your clients appreciate your abilities, and compensate you accordingly.
The samples in your tester are similar to my centrally spliced gantry hoist track problem. I'm trying to determine where to best locate splice plate bolts so their holes minimally weaken the four 4" x 5.4 channels that comprise the track. Maybe along the web's neutral axis, if the web has sufficient bearing strength or I weld on reinforcements?
Another possibility is welding loose-pin hinge leaves under the lower flanges to take the tension. https://en.wikipedia.org/wiki/Knuckle_joint_ (mechanical)
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I'd like to help you with this, if I can. Sorry - been preoccupied getting the "testing" thing going
I'll see if can find past articles where you describe the issue. Do you have a webpage you post pictures and articles to - like I do? So I can see what you mean?
Regards, Rich Smith
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"Richard Smith" wrote in message

I'd like to help you with this, if I can. Sorry - been preoccupied getting the "testing" thing going
I'll see if can find past articles where you describe the issue. Do you have a webpage you post pictures and articles to - like I do? So I can see what you mean?
Regards, Rich Smith --------------------------------
So far what I have is four 8' sections of 4" x 5.4 lbs/ft channel iron, which are former pallet rack shelf supports, and a Harbor Freight gantry hoist trolley to run on them when bolted back-to-back like an I beam. https://www.harborfreight.com/1-ton-push-trolley-97392.html
I built a lighter version from four 8' sections of 3" channel, with two hung back-to-back from the front and rear roof beams of a storage shed and two more making a temporary track extension out over the path past the shed, where I set up the sawmill and load logs and beams to/from a narrow trailer. The moving overhead hoist is very useful to move logs onto the sawmill bed and adjust the partly sawn cants, by suspending them in a loop of nylon rope hung on a pulley so I can easily turn and level them. The rolling bandsaw mill head needs nearly 8' of clearance between the shed and the track's outer end support post
That part works quite well for 8' oak logs and 6" square beams for shed columns. I have to set up the overhead extension track by my self and one channel's weight is near the max that I can maneuver with one hand while inserting bolts with the other. Safe handling and a shortage of covered storage space are why I don't use a single 16' beam (~240 lbs) for the track.
The problem is 12' logs for roof beams, which could overload the 3" channel and won't fit the 10' deep shed. I have another shed 19' long by 4' wide that can hold 12' beams if I hang a crosswise travelling hoist from its roof to move them in. It contains some already, which I moved by an unsatisfactory temporary arrangement of the 3" extension channels. I'd like to run the 4" channels out 8' over the sawmill to a braced post beyond it and in through the shed plus 4' out the far side to another post, for lifting logs off the trailer. In that case the track will be centrally supported from above at the joint between its 8' sections, no problem.
The extreme case is joining the four sections to make one 16' gantry track hung from tripods at the ends, perhaps to load a bulky appliance onto a truck. I may never need it but I'd like to find a center splice joint design that doesn't exclude or conflict with the central mounting from the shed roof beam. Hopefully one design will work for both centrally and end supported cases. That knuckle joint under the tension flanges looks good because I could raise the ground-assembled track by it and then lift and level the two outer ends separately, and it won't transfer sag on one side into lift on the other, and shift a shed column off its footing. I don't quite know how to design one to weld onto the channel flanges, for instance how much to taper the leaves to distribute the elongation and weld shear stress.
Specifically I'd like to know if bolts in tapped holes in the upper flange can be considered part of the compression area and the accepted way to reinforce the holes for splicing plate bolts through the channel web. Does the reinforcement need to be diamond shaped to avoid vertical welds?
Since I'm not on the clock I can customize bolts on the lathe and hand-fit them with minimal clearance. They are all Grade 8, fine thread, 150KSI.
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Starting a thread, "gantry - channel sections"
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"Richard Smith" wrote in message ... What should I be asking them for? They have a lot of stuff, and many big industrial customers, so I need to have a good idea and and get very close to the final solution - within reach of them being able to suggest detailed optimisation. --------------------------------------
That's a difficult question when your idea is innovative. When I was prototyping a lab demo of a multiplexed laser crosslink between satellites I couldn't directly mention it, or people would look at me as if I was hearing voices from outer space. I had to define the items I wanted to buy in down-to-Earth terms they recognized, then quietly modify them into what I needed, sometimes in my basement machine shop. A warped part that was too thin to flycut flat had to be fitted to its heatsink by smoking and scraping, like an old-time British gunsmith.
One of the engineers involved had helped design the Apollo lunar lander computer and told me the real story of its supposed failure. It ran a loop of all its tasks, one of which was to reset a hardware timer that would light a warning lamp if it ever timed out, presumably because the computer had crashed. As designed there was plenty of timing margin, but after he moved on the inevitable '"feature creep" kept adding more to do and the moon landing put unexpected demands on the software, such that the timer wasn't being reset soon enough and the warning lamp flickered on between timeout and reset. The computer was still working perfectly.
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"Richard Smith" wrote in message
I've done calculations, and in view of experience I have, this is the "bottom line" - the biggest cylinder needed v 50Tonne cylinder with 50mm stroke.
----------------------------------------------
https://tinyurl.com/ydeq8w9z
The featured item could convert your frame into a tension tester, and the 50 ton, 2" (50mm) cylinder is shown below. I needed more than a 50mm throw to fold weld test coupons double.
I bought several spare pairs of the quick disconnect couplers from a local supplier. They can for example allow temporarily adding a fragile pressure gauge on a tee to the hose. One coupler salvaged a hydraulic lift table I bought cheap because its motorized pump had failed.
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Pressure gauge which is removable - connect in line, only when needed - when doing something which does need a measurement - a test or a tensioning activity. Has hydraulic couplings and can be there in-line, or can be absent.
Question - would one pump and one cylinder, a 50Tonne 50mm stroke single-acting, be enough for now? Strategy completed by --- get two pressure gauges, one to 700+Bar, one to say 100Bar, so can accurately read off the pressure for both high-force and low-force tests?
Can you think of a solution to a problem of recording the maximum pressure at which the sample broke?
With the fillet weld test, there is no warning in any form of when the sample is about to break. Which it does instantaneously with a loud "BANG". So as you pump you have to do "lines and make a gate" with a pencil on a paper pad (after four lines, you do a diagonal line, and the sixth line starts what would become another set of five). So when the "BANG" happens, you have a persistent tally of what pressure had been reached. Clumsy and the gauge is more accurate than that records.
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"Richard Smith" wrote in message
Can you think of a solution to a problem of recording the maximum pressure at which the sample broke?
----------------------------
Video.
I use the free VLC Player to extract relevant clips from longer recordings.
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"Richard Smith" wrote in message
Pressure gauge which is removable - connect in line, only when needed - when doing something which does need a measurement - a test or a tensioning activity. Has hydraulic couplings and can be there in-line, or can be absent.
Question - would one pump and one cylinder, a 50Tonne 50mm stroke single-acting, be enough for now? Strategy completed by --- get two pressure gauges, one to 700+Bar, one to say 100Bar, so can accurately read off the pressure for both high-force and low-force tests?
Can you think of a solution to a problem of recording the maximum pressure at which the sample broke?
=======================When I built custom industrial test stations I used a Greenlee hydraulic knockout set to punch holes in steel boxes for controls and conduit. The combination of a heavy cylinder and hand pump on opposite ends of a stiff springy hose is impossible to fully control with only two hands, and the free end hits hard when it falls. Even when working on the floor the pump or cylinder tended to flip over hard enough to damage an attached gauge.
I'd say that the pump, cylinder and gauge are enough to get started, and the modular Porta-Power system is easy to expand later as needed. In my steel scrap collection is a press-like rectangular frame someone made from 1.250" hydraulic piston rod joining two drilled steel bars. Do you have a thread-cutting lathe and milling machine to make similar fixturing? Messing with hydraulics quickly took me beyond what a bandsaw, drill press and welder could do, although I bought all the high pressure fittings.
I had to machine a retainer for the low profile hydraulic cylinder of the 10,000 Lb force gauge I added to my sawmill, and repair the pressure gauge on a tire inflater that a springy hose pulled off the sawmill when I was away.
I assembled a cheap and simple data logger for slowly changing signals from an old laptop and meters like this: https://tekpower.us/multimeter/digital-multimeters/tp4000zc.html For my solar power application the optical isolation between channels is vital. If you acquire a pressure sensor with an analog voltage or current output the meter's .CSV data file can be read into a spreadsheet and easily converted to match your calibration measurement.
There are inexpensive DRO (distance) scales available to retrofit machine tools but I've never tried to connect one to a computer.
As first a chemist and later an electronic test tech I learned how to make measurements to 0.01%, and also that there's no point trying to greatly exceed the accuracy of your worst instrument or the inherent randomness of your subject. In non-critical mechanical testing 5% accuracy is good enough, which might be 20% of the full gauge scale although higher than half scale is preferable.
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Yesterday
* rebuilt hydraulic cylinder with new seal and it's good
That's the one which started leaking back in mid November http://www.weldsmith.co.uk/tech/struct/201113_u_rhs/201120_U_RHS_make_analyse_test.html when doing this (test of RHS test-weldment)
So now I'm fully rehabilited as "persona grata" amongst my workmates.
Little hint I'd offer - the seal seals so well, do drip some hydraulic oil on top of it before screwing together the cylinder, so it slides easily (?!?)
* fillet weld tensile breaking force test rig worked
Pic. of
http://www.weldsmith.co.uk/tech/struct/210122_fwtest_rig/pics_fwtr/210122_fwtest_rig.jpg
Time to get a pressure-gauge - to get F=P*A estimate of force.
That said - with Co.'s pump and cyl. (the one I put the new seal in) - I put the cylinder in the shop press, which has a force-applied gauge - so when you pump up the pump-and-cylinder, the press's gauge tells you how much force the cyl. is applying :-) So I know the pump's relief valve does operate at 700Bar, giving 10Tonnes force on that cyl. And you get in your mind a rough "calibration curve" of pump handle force to force applied by the cylinder :-)
Anyway, estimated 8 Tonnes when sample broke. Did maths just now - cyl. force to force across weld - using F_r_t=-F_p*L_m-a/2h (or, if F_w signified "force across the weld", F_w=-F_p*L_m-a/2h) of http://www.weldsmith.co.uk/tech/struct/201124_fwbeamt/201124_fwbeamt.html and as spacing central plate to "hoop"40mm (set using tape) L_m-a - say it is 350mm ("hoop" "beds" and can rotate a bit) and RHS is 100mm "tall" L_m-a/2h = 1.75 # (/ 350e0 (* 2 100)) # 8*1.75 - and get 14Tonnes Another estimate of 560MPa for the "G3Si1" ("ER70s-6") weld metal break strength :-)
This has been consuming my mind for weeks. Quite something that the hydraulics and the test fell into place on the same day yesterday! :-)
Best wishes,
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"Richard Smith" wrote in message ... This has been consuming my mind for weeks. Quite something that the hydraulics and the test fell into place on the same day yesterday! :-)
Best wishes,
----------------------
Congratulations!
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