Re: Google maintenance, dumping a fair post, James Brown, and a different type of press.

Lloyd,
A cheese press, Thanks.
When I posted this I figured I would get a least a "Hmmmm, might work".
You layed out the whole mechanics, thanks again.
Now to be accountable.
I've been the maintence man for 2 machine shops.
No, I have never been taught how to use an arbor press.
I was taught the machinist trade by this old man who worked at Nashod,
Cheatum Co. for 50 years.
I guess he figured any goob could figure a press.
Of the more than a few thousand of bearings pressed, and internal
keyways I've broached I never gave maintenance to a press much more
than oiling, and keeping handle wiped off.
The press I use now is a cheap one, doesn't even have a rating on it.
I'll look at it tomorrow to see if it has front and side gibs.
Something tells me no.
It does hold if handle is balanced in arm.
I slide the arm out some to cheat on tough pulls, that's where I have
been bit.
I sometimes get in a hurry and leave the arm long on one side with it
at 12:00.
If it's at 11:00 I get it on fingers, and head.
1:00, I can take the short part of handle on the chin.
And, yea I stand by the handle 'cause I'm going to need it.
I think back and see that I've done more cussing around an arbor press
than any other tool, that and a hammer.
Only positive is, I've never shot anything out,YET.
No, I haven't used safe shop practice around the arbor press.
I never gave it much thought.
If you knew me better, you would know that I take a dressing down
proper.
I do listen.
Thanks Lloyd,
Dan




Lloyd E. Sponenburgh wrote:
"spartono'dan" <daniel_kaiser@xxxxxxxxxxxxx> wrote in message
news:1169042925.102278.177040@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
m-------------I-----o
i
Best I can do for diagram!
"m" is your hand holding lever, lever line runs down to the "I" which
is your ram, then runs over to "o" which is the pivot.
Pivot "m", lever line, and "I" ram DOWN to the little "i".
The dot on the little i is your compo, could you generate enough
pressure to push the dot into the i?
I have been using arbor presses for 28 years, and have had my fingers
smashed by the square arbor, been tagged on the chin, and the top of my
noggin by unbalanced arbor bar.
Please someone tell me they can follow!

I can follow. You've described an old-fashioned cheese press.

Yes, you can develop enough pressure this way. All you need to do is scale
the difference between the pivot and the load, and the pivot and the end of
the handle to the mechanical advantage you need. More pressure requires a
longer handle or a higher ratio of distance between handle and ram.

Suppose you require 1000lb to consolidate your comp, and you could
conveniently pull on the handle with 50lb of force. You would require a
20:1 mechanical advantage to produce 1000lb of pressure.

If the distance between the pivot and your handle was three feet, the load
would need to be 1.5-tenths of a foot from the pivot to produce the desired
pressure -- about 1.75".

The distance the ram would move is 1/20 the distance of the handle motion.
So if you obtain a 1-foot stroke on the handle, the ram would move 1/20 of
one foot, or about 5/8".

That's pretty inconvenient. It would mean either changing rams or
re-blocking the load after nearly every increment in a 3/4" i.d. tube.

BUT -- you've obviously never been taught how to properly use an arbor
press.

--If you've smashed fingers, you've not had your load properly stabilized,
and you were holding the load with your hand. That's dangerous and bad shop
practice.

--If your handle moves of its own accord when out of balance, you haven't
properly tensioned the gibs in the rack guide. That's bad practice, and bad
for the life of the pinion and the rack. When the rack, pinion, and guides
are lubricated, the gibs should be tight enough to just barely stop the
motion of the rack when the handle is fully out of balance and horizontal.
That little bit of drag won't adversely affect pressing, but increases the
safety of the press. You must tension both the tooth clearance gib screws
and the side clearance screws. Make sure the gib plates are in place, and
you're not just pushing against the rack with naked screw tips. They
require re-adjusting fairly frequently. It's considered normal daily
maintenance to check them.

--And "tagged on the chin"? Unless you were pressing on springs, I don't
know how the handle could move UP on its own! (?) Or did you mean that
you'd jutted your chin out into the downward path of the handle? <G>

-- And why in heaven's name would you _EVER_ have your head, shoulder, or
chin in the path of the handle? It's on the SIDE of the press! You should
stand enough to the side of the handle and far enough away from the press so
that the handle cannot hit you even if the load springs free.

You haven't described a dangerous tool. You've described dangerous use of a
reasonably safe tool.

LLoyd

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