Subject:
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Re: Inexpensive air tank found at WalMart!
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Newsgroups:
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lugnet.robotics
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Date:
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Sun, 13 Feb 2000 21:16:40 GMT
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Viewed:
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880 times
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In lugnet.robotics, David C. Pyatt writes:
> Think about using a hand tire pump to inflate a tire/tyre... it only has
> the capacity of the cylinder you are pumping... compare that to running a
> pnematic pump with no tank... you could never pump fast enought to keep up
> with an air chisel...
There are compressors that could keep up with that (and more), nut you
wouldn't want to connect the to your legos:)
> Now compare that to an air compressor with a tank... the compressor fills
> the tank with a large volume of air to be used upon demand... a small 10/15
> gallon tank could operate one air tool, a large 55/80 gallon compressor can
> power an entire autobody repair shop using multiple tools at once... (Realize
> also there is a duty cycle... you can't take more air out than is in there so
> there is a recovery time... but usually you build in duty cycle to the purpose
> you buy the compressor for. If you are inflating tires/tyres you don't need a
> 100% duty cycle... if you are tightening nuts with an impact wrench you aren't
> going to want a small tank that you can take 3 nuts off then have to wait for
> 5 minutes for the tank to refill.
I've been toying a bit with pneumatics, and I really like them, have a few
tanks too, but I'm not sure how good they are.
If you take one tank and give it the 30-35 pumps to reach max pressure, you
have enough air for about 6-7 "actions" with a large cylinder, of which only
the first 2-3 are effective, now I could add another tank, giving me 60-70
pumps, 12-14 "actions" of which 4-6 are effective.
Continue the maths for yourself:)
What we really need are pressure regulators before the tanks get effective.
I usually use no airtank and a pump, or no airtank and a single cylinder
compressor, or one airtank and a four cylinder compressor.
The single cylinder compressor cannot fill the tank in a reasonable amount of
time, and since my pneumatics constructions usually uses a lot of air, it
would simply sit around waiting for the pressure to build most of the time.
(I've actually fitted a single cylinder compressor into the 8459, giving a
reasonable good responce)
I'm raving here...
My point is the larger the airtank is, the more you'll have to pump for volume
instead of pressure.
My most efficient setup is a 4 cylinder compressor, using a large cylinder for
airtank. The large cylinder is loaded with heavy rubberbands, giving full
pressure for the entire volume.
There is just enough air for one effective "action" and the pressure is always
up, and the compressor builds volume really fast:)
I'm up for small tanks and very high pressure.
Finally, my view on pressure overloads:
It looks like the compressor Ralph Hempel designed is rather popular, and it
is a good design, except that it isn't full stroke (I like full stroke
compressors).
But this compressor has one very big advantage, it doesn't need safety
devices: It can go on forever without blowing up:) meaning you can save the
space for a safety valve (the only reason to use on here would be to conserve
power in the batteries:))
Now I'm ranting again:)
Btw. The codepilot is brilliant for compressors:)
Regards
John
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Message has 2 Replies:
 | | RE: Inexpensive air tank found at WalMart!
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| John Jensen wrote... (...) Thanks John. Here's the URL in case some new folks don't know where the design is... (URL) (...) There is a regulator I designed using the polarity switch at... (URL) (...) Ahhh. I just got the BarCode Truck in the mail a (...) (25 years ago, 13-Feb-00, to lugnet.robotics)
| | | Re: Inexpensive air tank found at WalMart!
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| I guess I jumped around a little in my analogy... (...) (A HAND PUMP) fast enought to keep up (...) ... (...) Agreed... (...) What do you think of a bladder-filled air tank similar to a water tank? Would it have any advantages? Dave (25 years ago, 13-Feb-00, to lugnet.robotics)
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Message is in Reply To:
| | Re: Inexpensive air tank found at WalMart!
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| Think about using a hand tire pump to inflate a tire/tyre... it only has the capacity of the cylinder you are pumping... compare that to running a pnematic pump with no tank... you could never pump fast enought to keep up with an air chisel... Now (...) (25 years ago, 13-Feb-00, to lugnet.robotics)
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