how to remove old posts

On Thu, 12 Nov 2009 07:47:28 -0700, rw wrote:

mr.rapidan wrote:
On Nov 9, 1:27 pm, ooglyboogly wrote:

How may I, or whom may I contact, to remove those posts?


Look, you've probably figured out by now that removing old posts isn't
the easiest thing in the world but, if you're determined, it can be
done.

Things You'll Need:

* Bricks
* Concrete Blocks
* Measuring Tapes
* Heavy Piece Of Lumber
* Ropes
* Common Nails
* Hammers
* Shovels

Step 1
Remove the dirt from around the post.

Step 2
Measure up about a foot from ground level and drive a nail
halfway into each face of the post.

Step 3
Put a stack of bricks or concrete blocks at the edge of the area
you dug out.

Step 4
Lay a heavy piece of lumber across the bricks - this will act as
a lever to pull the post up out of the ground.

Step 5
Wrap a strong rope around the post under the nails (the nails
will hold the rope in place).

Step 6
Tie the ends of the rope to the lever. Press down on the other
end of the lever. You, and maybe another person, might have to stand
on it.

It seems to me that a simple lever won't give much mechanical advantage.

Maybe he could load up a fly rod....

Uh-oh,
R

On Nov 12, 8:47*am, rw wrote:
mr.rapidan wrote:
On Nov 9, 1:27 pm, ooglyboogly wrote:

How may I, or whom may I contact, to remove those posts?

Look, you've probably figured out by now that removing old posts isn't
the easiest thing in the world but, if you're determined, it can be
done.

Things You'll Need:

* * * Bricks
* * * Concrete Blocks
* * * Measuring Tapes
* * * Heavy Piece Of Lumber
* * * Ropes
* * * Common Nails
* * * Hammers
* * * Shovels

* * * Step 1
* * * Remove the dirt from around the post.

* * * Step 2
* * * Measure up about a foot from ground level and drive a nail
halfway into each face of the post.

* * * Step 3
* * * Put a stack of bricks or concrete blocks at the edge of the area
you dug out.

* * * Step 4
* * * Lay a heavy piece of lumber across the bricks - this will act as
a lever to pull the post up out of the ground.

* * * Step 5
* * * Wrap a strong rope around the post under the nails (the nails
will hold the rope in place).

* * * Step 6
* * * Tie the ends of the rope to the lever. Press down on the other
end of the lever. You, and maybe another person, might have to stand
on it.

It seems to me that a simple lever won't give much mechanical advantage.

The mechanical advantage of a simple lever (a first class lever, based
on the description in this instance) is purely a function of the
relative lengths of the beam on either side of the fulcrum. Thus,
using a six foot bar with the fulcrum an inch from the post would
yield a mechanical advantage of 71:1. A downward force of 50 pounds
applied to the long end of the lever would translate to an upward
force of 3550 pounds of upward force at the short end. You should
have learned this in about the third grade. So, I guess it all
depends on what you call "much."

I've used a jack to remove posts. A heavy duty jack works best, but in a
pinch any car jack should work.

Mechanical jacks generally work on the principle of a simple lever.

g.

On Nov 12, 9:04*am, wrote:
On Thu, 12 Nov 2009 07:47:28 -0700, rw wrote:
mr.rapidan wrote:
On Nov 9, 1:27 pm, ooglyboogly wrote:

How may I, or whom may I contact, to remove those posts?

Look, you've probably figured out by now that removing old posts isn't
the easiest thing in the world but, if you're determined, it can be
done.

Things You'll Need:

* * * Bricks
* * * Concrete Blocks
* * * Measuring Tapes
* * * Heavy Piece Of Lumber
* * * Ropes
* * * Common Nails
* * * Hammers
* * * Shovels

* * * Step 1
* * * Remove the dirt from around the post.

* * * Step 2
* * * Measure up about a foot from ground level and drive a nail
halfway into each face of the post.

* * * Step 3
* * * Put a stack of bricks or concrete blocks at the edge of the area
you dug out.

* * * Step 4
* * * Lay a heavy piece of lumber across the bricks - this will act as
a lever to pull the post up out of the ground.

* * * Step 5
* * * Wrap a strong rope around the post under the nails (the nails
will hold the rope in place).

* * * Step 6
* * * Tie the ends of the rope to the lever. Press down on the other
end of the lever. You, and maybe another person, might have to stand
on it.

It seems to me that a simple lever won't give much mechanical advantage.

Maybe he could load up a fly rod....

Uh-oh,
R

Moron.

g.

Giles wrote:
On Nov 12, 8:47 am, rw wrote:

It seems to me that a simple lever won't give much mechanical advantage.


The mechanical advantage of a simple lever (a first class lever, based
on the description in this instance) is purely a function of the
relative lengths of the beam on either side of the fulcrum. Thus,
using a six foot bar with the fulcrum an inch from the post would
yield a mechanical advantage of 71:1. A downward force of 50 pounds
applied to the long end of the lever would translate to an upward
force of 3550 pounds of upward force at the short end. You should
have learned this in about the third grade. So, I guess it all
depends on what you call "much."

I just calculated the mechanical advantage of the jack for my F150. It's
163:1 +/- 10% -- more than twice as much as your hypothetical lever.
You'd need a lever of about 13' to match it. Good luck finding one with
enough bending strength to handle a stubborn post.

I've used a jack to remove posts. A heavy duty jack works best, but in a
pinch any car jack should work.


Mechanical jacks generally work on the principle of a simple lever.

Some do, but not screw jacks, such as the one from my F150. Like all
"screws," they operate on the principle of the inclined plane.

By the way, another very big advantage of a jack over a simple lever for
removing posts, and maybe even more important than mechanical advantage,
is holding power. Lever-type jacks will have ratchets. Screw jacks don't
need them.

Try removing a 6" diameter post buried 4' deep with a simple lever, and
then try it with a decent jack, and then get back to me.

--
Cut "to the chase" for my email address.

On Nov 12, 11:29*am, rw wrote:
Giles wrote:
On Nov 12, 8:47 am, rw wrote:

It seems to me that a simple lever won't give much mechanical advantage..

The mechanical advantage of a simple lever (a first class lever, based
on the description in this instance) is purely a function of the
relative lengths of the beam on either side of the fulcrum. *Thus,
using a six foot bar with the fulcrum an inch from the post would
yield a mechanical advantage of 71:1. *A downward force of 50 pounds
applied to the long end of the lever would translate to an upward
force of 3550 pounds of upward force at the short end. *You should
have learned this in about the third grade. *So, I guess it all
depends on what you call "much."

I just calculated the mechanical advantage of the jack for my F150. It's
163:1 +/- 10% -- more than twice as much as your hypothetical lever.

Hm.....it might be interesting to see the math on that. And what is
the mechanical principle upon which that jack depends? Incidentally,
my lever isn't hypothetical. I have a six foot long steel bar that
has been put to use as a lever many times. I generally find something
or other in situ to use as a fulcrum.

You'd need a lever of about 13' to match it.

I expressed an interest in finding something to match your
hypothetical jack and no one told me? tsk tsk.

Good luck finding one with
enough bending strength to handle a stubborn post.

Depends on the size and stubbornnes of the post. I've removed many
with significantly less than 13' levers.

I've used a jack to remove posts. A heavy duty jack works best, but in a
pinch any car jack should work.

Mechanical jacks generally work on the principle of a simple lever.

Some do, but not screw jacks, such as the one from my F150. Like all
"screws," they operate on the principle of the inclined plane.

And what propels the screw?

By the way, another very big advantage of a jack over a simple lever for
removing posts, and maybe even more important than mechanical advantage,
is holding power.

No ****?

Lever-type jacks will have ratchets.

Not all of them. Some are hydraulic. If we ever get through this
tedious lesson, leaving you with a rudimentary understanding of simple
levers, we may move on to that.

Screw jacks don't need them.

No ****?

Try removing a 6" diameter post buried 4' deep with a simple lever, and
then try it with a decent jack, and then get back to me.

Done it both ways.....and other ways as well. My personal preference
is a nice hydraulic back hoe or something similar. Your going to have
a hard time making me believe you've ever done it by whatever
method.......a natural result of your obvious failure to understand
something as simple as a lever.......while describing its hypothetical
use.

g.

How 'bout financial advantage. If you loaned the makers of Paranormal
Activity 10,000 of the 15,000 required to make the movie, you could
hire 23 Cuban midgets to pick up your F150 then use it to pound the
post all the way into the ground.
Money spent on making movie = $15,000
Gross box office receipts = $97 million
Look on the face of the guy that turned your movie investment deal
down = Priceless

Frank Reid

Giles wrote:
On Nov 12, 11:29 am, rw wrote:

I just calculated the mechanical advantage of the jack for my F150. It's
163:1 +/- 10% -- more than twice as much as your hypothetical lever.


Hm.....it might be interesting to see the math on that.

I'm glad you asked that question, because in answering it I realized
that my math was wrong. The mechanical advantage of my F150 screw jack
is actually twice what I calculated, or 326:1. (You'd need a lever 27'
feet long to match it.)

Determining the mechanical advantage of a screw jack depends on two
measurements: the pitch of the screw helix and the radius of the crank.

In this case:

pitch: P = 1 mm

crank radius: R = 26 mm

The circumference of the circle (of diameter D) subsumed by the crank is:

C = 2*pi*D = 2*pi*(2*R) = 326 mm

The mechanical advantage is:

A = C/P = 326

My careless mistake was using the radius for the diameter.

I generally find something
or other in situ to use as a fulcrum.

Something 27' long?


Done it both ways.....and other ways as well. My personal preference
is a nice hydraulic back hoe or something similar. Your going to have
a hard time making me believe you've ever done it by whatever
method.......a natural result of your obvious failure to understand
something as simple as a lever.......while describing its hypothetical
use.

Well, if you have a backhoe this whole discussion is irrelevant.

A hydraulic jack would be a good choice. I used them to raise my cabin
when I replaced the foundation two years ago. I could probably dig up
some photos.

--
Cut "to the chase" for my email address.

On 2009-11-12 09:47:28 -0500, rw said:


It seems to me that a simple lever won't give much mechanical advantage.

I've used a jack to remove posts. A heavy duty jack works best, but in
a pinch any car jack should work.

Doctor, Doctor! We have a winner in the orchestra!

Anyone who can remember highschool physics would know that, Steve.
Long, long time ago, eh?

Joanne once moved a 400 pound rock about 45 feet in a very short time
using a 6 foot pry bar. She weighed about 120 lbs.

Dave

David LaCourse wrote:

Joanne once moved a 400 pound rock about 45 feet in a very short time
using a 6 foot pry bar. She weighed about 120 lbs.

Downhill? :-)

--
Cut "to the chase" for my email address.

"David LaCourse" wrote Joanne once moved a 400 pound
rock about 45 feet in a very short time
using a 6 foot pry bar. She weighed about 120 lbs.

well, she sure as hell has had plenty of practice with regard to that
sort of activity, having lived with you for a duration of years...

yfitons
wayno(the thought of *literally* kicking your ass is challenging, indeed...)