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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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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 |
#2
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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/ |
#3
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"Jim Wilkins" writes:
"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/ 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 |
#4
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Richard Smith writes:
"Jim Wilkins" writes: "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/ 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. |
#5
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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. ---------------------------------------------------------- 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-...ress-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 |
#6
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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. |
#7
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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. |
#8
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On Thu, 24 Dec 2020 18:27:06 -0500, "Jim Wilkins"
Molten glass does this: https://en.wikipedia.org/wiki/Prince_Rupert%27s_drop Also known as Czar's Tears. Joe Gwinn |
#9
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"Jim Wilkins" writes:
"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. 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. |
#10
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On 25/12/2020 20:00, Joe Gwinn wrote:
On Thu, 24 Dec 2020 18:27:06 -0500, "Jim Wilkins" Molten glass does this: https://en.wikipedia.org/wiki/Prince_Rupert%27s_drop Also known as Czar's Tears. Joe Gwinn 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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