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View Full Version : Arbor press tonnage?



Doc Nickel
08-12-2003, 04:38 PM
Rather unimportant question, but thought I'd ask anyway: How (or why) do they rate arbor presses?

I just picked up one of ENCO's imports (2 ton, 88lb, on sale for $50; MSC has an 88lb 2-ton for $135, go fig http://bbs.homeshopmachinist.net//biggrin.gif ) and once cleaned up and the gibs adjusted, it works quite well.

But, I was wondering, where do they get the "2-ton" rating? Do they figure the average bloke is 200 lb and the rack is 10:1?

Doc.

Dr. Rob
08-12-2003, 05:39 PM
Good question; I've wondered myself. Have something similar myself, but the arm/handle is like four feet long.

kenc
08-12-2003, 06:17 PM
Aaarrgghhhh! Doc!

Don't let "like" get into the written word as well as the spoken.........
If you live in CA, as I do, those redundant "like"s will drive you nuts!

lynnl
08-12-2003, 06:45 PM
Ken you and I have at least one thing in common. The problem is, all that stuff starts in CA and then spreads to the whole country. Remove 'like' and 'you know' from the spoken language and most of today's youth might as well be mute. ...hmmm, come to think of it that might not be a bad idea. http://bbs.homeshopmachinist.net//biggrin.gif

Regarding the arbor press ratings: I've always assumed that was the point beyond which the things might be expected to break (ie. weakest component).

DR
08-12-2003, 06:47 PM
The ratings are based on the amount of tonnage the press frame will handle without breaking.

Thrud
08-12-2003, 06:49 PM
Doc Nickel, Ken:

Like, wow - man. As long as the handle don't like bend - then you can exceed that tonnage - like if you're a big fat dude like me.

Like, totally gnarly dude! http://bbs.homeshopmachinist.net//biggrin.gif

Sorry Ken, could not like help myself... http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//eek.gif

Oso
08-12-2003, 06:57 PM
Thrud.....

Dude, that info is like completely deck.

Thanks

tonydacrow
08-12-2003, 07:22 PM
Yo, yo, yo, You. Dudes be totally whack!

No gnarly wag-jiz worth his props wouldn't diss a jag-bit poo-butt jiggy-be. S'up dat Five-Oh?

Evan
08-12-2003, 07:35 PM
Was ist hier los?? Es war meine Verstehung dieses ist einen Englisch Sprechender BBS.

[This message has been edited by Evan (edited 08-12-2003).]

Joel
08-12-2003, 08:10 PM
Viellicht warren sie einmahl unrecht.

Shed Machinist
08-12-2003, 08:54 PM
Ok, am 13 so i know what is being said nowadays. but since i know, i couldn't tell you for lack of knowing what i am saying different? Do you know what i am saying? You just have to listen to what i am saying, ok!

Shed Machinist
08-12-2003, 09:00 PM
Evan ???

What is here loose?? It was is my Verstehung this an English of speaking BBS.

I tryed to get this translated. Did i get it right? If i did what is a verstehung?

Doc Nickel
08-12-2003, 09:04 PM
The irony here is that most of this conversation came off from Ken's tangent about using the Vally-girl-ism "like", when in fact that word does not appear in my original post in any form.

Doc.

kenc
08-12-2003, 09:04 PM
Shed guy,
You're like out of it Dude, I mean, like it's not "Do you know what I'm saying" it's like "Smell me?" these days.

;-)

Evan
08-12-2003, 09:07 PM
Joel,

Måske i denne omgang.

[This message has been edited by Evan (edited 08-12-2003).]

Evan
08-12-2003, 09:09 PM
Shed,

Verstehung = understanding.

The translation is ok but not great. Most machine translations can't cope with slang and have a hard time with inverted word order. "Was ist heir los?" really means "what's up here?" or "What's going on?"

[This message has been edited by Evan (edited 08-12-2003).]

Shed Machinist
08-12-2003, 09:16 PM
German right?

Evan
08-12-2003, 09:20 PM
Yeah, German. What about the second phrase?

Shed Machinist
08-12-2003, 09:21 PM
It wouldn't translate

wierdscience
08-12-2003, 10:09 PM
Like Kennedy said"Hitchpin I'n Belinda" http://bbs.homeshopmachinist.net//biggrin.gif
Don't forget to pak da ca and lets go pady! http://bbs.homeshopmachinist.net//biggrin.gif

Thrud
08-12-2003, 10:20 PM
Doc
Yeah...!

kenc
08-13-2003, 12:26 AM
Doc,
Sorry.
It's in "Dr. Rob"s follow up to your post.
Dr = Doc.
My fault for confusing you!
Ken

[This message has been edited by kenc (edited 08-12-2003).]

Evan
08-13-2003, 12:45 AM
Måske i denne omgang=Danish=Perhaps I am this time

dvideo
08-13-2003, 12:57 AM
What Kennedy really said was... "I am a (popular) jelly donut"... which greatly confused the W. Berlinrers and seriously trouble the E. Berlinners - "This jelly donut has nukes!!!"...

I guess if you cannot intimidate them, confuse them... or even better.... worry 'em...

-- jr

Evan
08-13-2003, 01:13 AM
Dvideo,

He did accomplish that. He should have said "Ich bin Berliner", "I am from Berlin/a Berliner". He said "Ich bin ein Berliner", Meaning actually "I am a donut", or, considering his political importance it would be construed in the context of, "I am THE donut". I suppose this may have had the Easterners scrambling to figure out if this meant something like "I am the BIG cheese" or only meant that he needed to execute his translator.

[This message has been edited by Evan (edited 08-13-2003).]

Dr. Rob
08-13-2003, 02:08 AM
Kenc! All right, a fully accurate obsevation that I am generally in agreement with, along with the rest of this thread.

BUT BUT BUT

I meant it. The handle is indeed a lot like four feet long. Maybe it is 3'8", or 4'2". I don't know since it can't be seen from here.

So it is indeed approximately, similar to, or LIKE four feet long.

Sorry.

pgmrdan
08-13-2003, 09:16 AM
.

[This message has been edited by pgmrdan (edited 03-08-2004).]

lynnl
08-13-2003, 10:53 AM
Gag me with a fork. 'er is that a spoon. ...whatever.

docsteve66
08-18-2003, 12:03 AM
The press force?
A five ton press should be able to exert five tons of force (pressure) (NOT Psi) at the working end. I have measured no arbor presses, but many hydraulic jacks. All most without exception, 40 pounds at the end of the handle develops the pressure required to lift the maximum load. 40 pounds force from a man appears so often in legal restrictions (or used to appear) that i suspect 40 pounds on a arbor press will develop the rated force also. It would be easy to reverse engineer: figure the mechanical advantage by gear ratio and lever arm length, set the ratio to the "rated force" and see what the input would be. Then you have to guess at the engineers "safety factor". I know hydraulic jacks rams have "O" rings that in some cases exceed 10,000 psi when operating at max load. Smaller jacks with big rams are rated at lower pressures. I used to routinely overload the jacks by calculating the load that would be required to reach the pressures I felt they could stand. i never had a jack fail, and i overloaded them by a factor of five or more FOR SMALLER jacks. I have never (knowingly) exceeded 20,000 PSI at the ram. I pucker when i exceed the 10,000 PSI figure (which I consider to be a conservative, safe figure)
Steve

Evan
08-18-2003, 12:43 AM
Hmmm... A very simple high capacity scale may be made with a chunk of steel with a hole of 1.129 inches diameter and a similar sized piston with O ring to seal it, oil filled. Then use a standard pressure guage in the side such as used on an oxygen tank up to 2500 psi. It will read weight directly on the guage in pounds.

Oso
08-18-2003, 02:11 AM
I don't believe the 40 lb thing, I have seen a few arbor presses, and it don't work.

take a 1 ton press. 2000 lb force.

pinion is about 1.5 inch diameter. so lever arm is 3/4 inch, or 1500 inch lb. Might be bigger diameter, which makes it worse.

Lever is about 15 inches long, maybe. Might be shorter.

Say 15.......so that gives 100 lb force required at the end of the lever, or somewhat more at the center of your hand when holding it.

With friction and "hand width allowance", might be over 130 lb force on the arm required for 2000 lb force at the ram.

Doc Nickel
08-18-2003, 07:52 AM
<font face="Verdana, Arial" size="2">Originally posted by Evan:
Hmmm... A very simple high capacity scale may be made with a chunk of steel with a hole of 1.129 inches diameter and a similar sized piston with O ring to seal it, oil filled. Then use a standard pressure guage in the side such as used on an oxygen tank up to 2500 psi. It will read weight directly on the guage in pounds.</font>

That's very interesting. Can you explain the math to this mathematically-disinclined person?

I have a few spare gauges, I might just whip up a piston like that, and see what happens. I've always wondered what sort of force I could apply in the big bench-vise as well...

Doc.

Evan
08-18-2003, 12:52 PM
A hole of 1.129 inches diameter has an area of one square inch, hence the guage will read in pounds directly. Scales like this are used to weigh aircraft when doing a weight and balance check.

Thrud
08-19-2003, 02:25 AM
They are called "load cells". Very easy to make. Sherline sells them.

Forrest Addy
08-19-2003, 02:57 AM
Cutting to it. A tonnage rating is usually nominal - just a name. The press may or may not exert a ton of ram force using ordinary effort.

Those cheap import arbor press frames are pretty stout. I'd think the rack or pinion would fail long before the frame broke. A 1 ton arbor press with a 5 ft pipe cheater on the handle might go 3 tons or more before you deform/break a tooth.

.... dewwwwd!


[This message has been edited by Forrest Addy (edited 08-19-2003).]