air over hydraulics info wanted

I am looking at the Harbor Freight air- over hydraulic jack that is for
sale in their latest flyer. And I am wondering what kind of cfm's is
needed to make that operate well?
Reply to
Michael
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Assuming it's the 20 ton, SKU 41487, I have one, pulled out the assembly/operating instructions, doesn't spec the CFM. More air at 90 psi will make it pump longer. If your air pressure drops below 90 psi it will run slower. I run an air-over-hydraulic 8-ton long-throw jack all the time on my shop hoist, and that one has to run for a long time to move all the way, and it completely outruns my compressor which delivers an honest 17 CFM. (5 horse 2-stage Quincy) But the compressor catches up quickly.
I use the 20 ton in my shop press, and the ram rarely has to extend over a couple of inches. I don't recall ever having the 20-ton exceed my compressor's ability to deliver.
Sorry for the non-definitive answer, hope it helps a little.
GWE
Reply to
Grant Erwin
Grant, how do you like that jack, I looked into it also and hesitated to buy. Would appreciate some feedback.
i
Reply to
Ignoramus31101
I like mine fine. Really exceptional value for the money. A blacksmith I know named Steve Smith (posts here on occasion) also has one and I believe he says he uses his in his forging press and likes it too.
Even if the air-over unit broke entirely it would still work fine as a regular bottle jack, in other words you can always pump it by hand.
Mine's relatively nicely made and works just fine.
When they're on sale for $79.99 (most of the time) and you can score one of those elusive 20% off coupons (which seem to have disappeared from the place I'd bookmarked, anyone know where they went?) they're very inexpensive.
I use mine on a 20 ton shop press.
GWE
Reply to
Grant Erwin
I got one and put it in my 20T H frame press. I like it and haven't found any faults. Hard to beat at about $65 with coupons and whatnot.
Pete C.
Reply to
Pete C.
Weren't me. My forging press has a plain 6" hydraulic cylinder I got at a fine junkyard in Colorado (Martin's Salvage). It started life as one of the cylinders in a trash truck. I run it off of a log splitter pump (2 speed).
Steve
Reply to
Steve Smith
Hi Grant,
It looks like they've made some changes, no duh :)
Try:
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or if you are good with URL's and care to guess/figure out the current week, modify this to suit your needs:
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The latter was plucked from their email earlier this week.
Reply to
Leon Fisk

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