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Re: Raising a weight using hydraulics
Re: Raising a weight using hydraulics -- roger5	Post Reply	Top of thread	Forum

Posted by: hjens56 ® 12/13/2006, 03:47:06 Author Profile eMail author Edit

Roger, Does this weight have to be moved to a precise location, or just raised up a bit? Are there any time requirements for lifting the weight? Do you have space constraints underneath or around the weight? Answers to some of these questions may help determine which method is best to raise your weight.

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Re: Raising a weight using hydraulics
Re: Raising a weight using hydraulics -- roger5	Post Reply	Top of thread	Forum

Posted by: zekeman ® 12/10/2006, 12:04:37 Author Profile eMail author Edit

I would do it mechanically ,say with a simple worm and rack where you have complete control and safety. You would simply rotate the worm until you achieve the height and to lower it, you rotate in ther opposite direction. That way, the weight is always "locked" in any position.

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Re: Re: Raising a weight using hydraulics
Re: Re: Raising a weight using hydraulics -- zekeman	Post Reply	Top of thread	Forum

Posted by: roger5 ® 12/10/2006, 14:40:52 Author Profile eMail author Edit

I can't do it mechanically. In fact I have to do it "electronically", somehow using an RF signal to activate the lfting.

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Re: Raising a weight using hydraulics
Re: Raising a weight using hydraulics -- roger5	Post Reply	Top of thread	Forum

Posted by: randykimball ® 12/10/2006, 09:27:59 Author Profile eMail author Edit

so... you want to push down with about 50 lbs added pressure to reset the unit? nah.. use air. ..KISS it....."Keep It Simple Stupid" You can use a small air tight tank with an air pump and a pressure gauge. You will need a tank about 5 times the volumn of the cylinder (3.14 x the stroke, on the size cylinder I'm recommending). You run a hose to the cylinder. Use a cylinder of about 2" in diameter. The power of the cylinder to lift is 3.14 x the presure in the tank. So the first time, you simply pump up the tank pressure to lift with the force you like. Then push down on the product or "table" to force it back down. Have a latch that holds the "table" down. Then release the latch for the "table" to lift. The amount of pressure you pump up into the tank will effect the speed that the load lifts and how hard you must push it back down. Having installed a hand pump you give the operator complete control over these forces. With the gauge you learn at what pressure to pump up to, so that there is enough pressure when the cylinder is extended. As the cylinder extends the presure in the tank drops per the increased total volumn. You will not need to do any math this way.... it just works.... wink.. As an enhancement, you could place a blocker valve between the tank and the "table". While the "table" is down close the blocker valve and the table stays down. Open the blocker valve and the table lifts. Blocker valves can be purchased that will operate by electric selonoid so a switch or button can offered to the operator. If you have an air supply, you can provide a pressure regulator from the main system to maintain the system at the best lower operating pressure in place of a hand pump. (I doubt you would be hand pumping very often as long as your system is good and air tight.) ...have a nice day, The worst suggestion of your lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them. Modified by randykimball at Sun, Dec 10, 2006, 09:44:55

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Re: Re: Raising a weight using hydraulics
Re: Re: Raising a weight using hydraulics -- randykimball	Post Reply	Top of thread	Forum

Posted by: roger5 ® 12/10/2006, 14:37:31 Author Profile eMail author Edit

Thanks for the reply. I would love to keep it simple, but I unfortunately have to keep it small too. Like max 1" diameter. I forgot to mention I can use 4 smaller units lifting 1/4 of the weight instead however. Is there any way to do this without the tank, just a cylinder?

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Re: Re: Re: Raising a weight using hydraulics
Re: Re: Re: Raising a weight using hydraulics -- roger5	Post Reply	Top of thread	Forum

Posted by: zekeman ® 12/11/2006, 01:31:30 Author Profile eMail author Edit

You can do it with one cylinder with the piston between two openings in the cylinder walls, a 4 way valve and a pressure source. I have done this numerous times to oscillate carriages in automation applications. You raise it by opening the top orifice(in the 4 wat valve) to atmospheric while pressurizing the lower half to a little more than 100 psi. On closing, you simply control the lower orifice to atmosphreric, allowing the weight to move ot downqward in a controlled manner. But you will need a small tank and a small compressor (or hand pump) to maintain the tank pressures.

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Re: Re: Re: Raising a weight using hydraulics
Re: Re: Re: Raising a weight using hydraulics -- roger5	Post Reply	Top of thread	Forum

Posted by: randykimball ® 12/10/2006, 23:03:21 Author Profile eMail author Edit

well, the fluid, be it air or hydraulic oil, must go somewhere when the cylinder is lowered. You can still use a 1" cylinder. With craftiness you can make the frame be the tank. The worst suggestion of your lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them.

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Re: Re: Re: Re: Raising a weight using hydraulics
Re: Re: Re: Re: Raising a weight using hydraulics -- randykimball	Post Reply	Top of thread	Forum

Posted by: roger5 ® 12/11/2006, 07:19:44 Author Profile eMail author Edit

Say I have to have an external tank providing air (or some other gas). Would the system be able to work in a self-contained way, ie. without having to introduce, every cycle, air from outside the system (the system being the tank and cylinder)?

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Re: Re: Re: Re: Re: Raising a weight using hydraulics
Re: Re: Re: Re: Re: Raising a weight using hydraulics -- roger5	Post Reply	Top of thread	Forum

Posted by: randykimball ® 12/11/2006, 22:51:38 Author Profile eMail author Edit

If you do it as I suggested, ..yes.. providing there are no leaks. The pump was suggested to top off the pressure when it eases down to the point it fails to perform or to change the pressure to suit a new operator. The worst suggestion of your lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them.

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