Release under tension

[Ignoramus22161]

I am thinking of making a set up to drop a heavy weight (old forklift
counterweight) onto objects, such as truck cabs and file cabinets, to
flatten them in preparation for scrapping. That way they will take
less room in the scrap gondola.

To drop that counterweight, it would need to be lifted with a
forklift, and then some sort of a release-under-tension would release
the object and it would fall.

I have compressed air nearby if I wanted to make that mechanism
pneumatic.

Any suggestion for something that could release an appx. 2-3 ton
weight?

i

[james g. keegan jr.]

On 10/9/2012 11:42 AM, Ignoramus22161 wrote:
>[...]

A good martini will help release the tension.

[Kristian Ukkonen]

There was such a device in Mythbusters episode, where they
dropped a lift (elevator) in a similar setup.. Some ready-made
device that drops a heavy load.. Elevator of death was the name
of episode, I think..

[Joe AutoDrill]

Maybe replace the forklift's cylinder with a cylinder that has very
large ports on the "exhaust side" and install a solenoid or air powered
"dump valve" to bypass the regular return track of the air/fluid?

--
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V8013-R

[Pete Keillor]

Dad made something similar 50 years ago or so. It was a hook mounted
on a big iron hoop to which we attached the winch truck cable. Imagine
a figure eight with the bottom hole cut open to the side. The open
part of the hook received a clevis tying the chain around a levee
roller spool, about 2 tons of concrete. At the top of the closed part
of the hook, he welded a 3-4 ft. rod of 1" bar at a slight angle off
vertical. A trip line was tied to that. The leverage was enough that
it was relatively easy to rotate the hook so the open part was down
and the clevis slipped out, dropping the spool.

Actually, it didn't work worth a damn, because the first thing he
tried it on was an old International Travelall. Dropped it smack in
the middle of the roof. It did just like stomping in the middle of a
soda can so it sticks to your shoe, something we did as kids. That
damned car wrapped around the spool and we played hell getting it off.
We hooked up to the spool without the trip hook and picked up the
whole car, spool and all. It took a lot of work with cutting torches
and pry bars to get that car off the spool. Dropping it on the ends
might have worked better.

I doubt OSHA would approve.

Pete Keillor

[Pete C.]

Joe AutoDrill wrote:
>
> On 10/9/2012 2:42 PM, Ignoramus22161 wrote:
> > I am thinking of making a set up to drop a heavy weight (old forklift
> > counterweight) onto objects, such as truck cabs and file cabinets, to
> > flatten them in preparation for scrapping. That way they will take
> > less room in the scrap gondola.
> >
> > To drop that counterweight, it would need to be lifted with a
> > forklift, and then some sort of a release-under-tension would release
> > the object and it would fall.
> >
> > I have compressed air nearby if I wanted to make that mechanism
> > pneumatic.
> >
> > Any suggestion for something that could release an appx. 2-3 ton
> > weight?
> >
> > i
> >
>
> Maybe replace the forklift's cylinder with a cylinder that has very
> large ports on the "exhaust side" and install a solenoid or air powered
> "dump valve" to bypass the regular return track of the air/fluid?

Sounds pretty dangerous for the forklift and slow.

My suggestion would be to make a shackle type setup with a hydraulically
operated hardened pin. Connect the hydraulic cylinder operating the pin
with a set of 1/4" twin hydraulic hoses to a control valve you can clamp
in a convenient place on the forklift and connect to the forklift
hydraulics with some quick connects. This gives you a 100% drop, not
just fast lowering, you don't have the whole forklift mast crashing down
potentially damaging the forklift and you get to install some handy
auxiliary hydraulic ports on the forklift.

[anorton]

"Kristian Ukkonen" <kristian...@iki.fi> wrote in message
news:ew_cs.31481$ck7....@uutiset.elisa.fi...

Maybe this is where Mythbusters got them:
http://www.sweeney-special-effects.com/special_effects_catalog.php?QR
or here
http://www.seacatch.com/products.htm

[Ecnerwal]

In article <xYKdnZ56qO2Z7enN...@giganews.com>,

Ignoramus22161 <ignoram...@NOSPAM.22161.invalid> wrote:

> I am thinking of making a set up to drop a heavy weight (old forklift
> counterweight) onto objects, such as truck cabs and file cabinets, to
> flatten them in preparation for scrapping. That way they will take
> less room in the scrap gondola.

There are good reasons this is generally done with a hydraulic ram,
rather than by dropping things. A hydraulic ram does not bounce...and 3
tons bouncing tends to damage things other than what you are trying to
crush.

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

[dpb]

On 10/9/2012 1:42 PM, Ignoramus22161 wrote:
...

> Any suggestion for something that could release an appx. 2-3 ton
> weight?

...

OK, Iggy, time to find that electromagnet crane that's on the auction
block... :) (Every scrap dealer needs one, anyway...)

--

[Ignoramus22161]

On 2012-10-09, Pete C. <aux3....@snet.net> wrote:
>
> Joe AutoDrill wrote:
>>
>> On 10/9/2012 2:42 PM, Ignoramus22161 wrote:
>> > I am thinking of making a set up to drop a heavy weight (old forklift
>> > counterweight) onto objects, such as truck cabs and file cabinets, to
>> > flatten them in preparation for scrapping. That way they will take
>> > less room in the scrap gondola.
>> >
>> > To drop that counterweight, it would need to be lifted with a
>> > forklift, and then some sort of a release-under-tension would release
>> > the object and it would fall.
>> >
>> > I have compressed air nearby if I wanted to make that mechanism
>> > pneumatic.
>> >
>> > Any suggestion for something that could release an appx. 2-3 ton
>> > weight?
>> >
>> > i
>> >
>>
>> Maybe replace the forklift's cylinder with a cylinder that has very
>> large ports on the "exhaust side" and install a solenoid or air powered
>> "dump valve" to bypass the regular return track of the air/fluid?
>
> Sounds pretty dangerous for the forklift and slow.

It would have to be something that hangs on the forks. Not something
that is plumbed into a forklift.

i

[Pete C.]

Ignoramus22161 wrote:
>
> On 2012-10-09, Pete C. <aux3....@snet.net> wrote:
> >
> > Joe AutoDrill wrote:
> >>
> >> On 10/9/2012 2:42 PM, Ignoramus22161 wrote:
> >> > I am thinking of making a set up to drop a heavy weight (old forklift
> >> > counterweight) onto objects, such as truck cabs and file cabinets, to
> >> > flatten them in preparation for scrapping. That way they will take
> >> > less room in the scrap gondola.
> >> >
> >> > To drop that counterweight, it would need to be lifted with a
> >> > forklift, and then some sort of a release-under-tension would release
> >> > the object and it would fall.
> >> >
> >> > I have compressed air nearby if I wanted to make that mechanism
> >> > pneumatic.
> >> >
> >> > Any suggestion for something that could release an appx. 2-3 ton
> >> > weight?
> >> >
> >> > i
> >> >
> >>
> >> Maybe replace the forklift's cylinder with a cylinder that has very
> >> large ports on the "exhaust side" and install a solenoid or air powered
> >> "dump valve" to bypass the regular return track of the air/fluid?
> >
> > Sounds pretty dangerous for the forklift and slow.
>
> It would have to be something that hangs on the forks. Not something
> that is plumbed into a forklift.

Yes, that's exactly what I said. You have a forklift lifting beam, do
you not? All you need is a shackle setup to hang from that to hold the
load. Something like a couple side plates of 1/2" steel with a top cross
pin to hang from and a hydraulic cylinder on the side controlling a
lower cross pin that goes through another steel plate that has a bottom
hole for a regular shackle your load hangs from. Pull the pin with the
hydraulics from the safety of the forklift and the load drops while the
forklift mast stays put. Lower down safely, refit the hang plate, set
the lock pin and repeat. Just a homemade version of the stunt shackles
that have been linked. Those have hydraulic and pneumatic activation
options as well. Perhaps find a good diagram of one of those and clone
it more fully.

[Stormin Mormon]

How do you get the tension back?

Christopher A. Young
Learn more about Jesus
www.lds.org
.
======================

[cl...@snyder.on.ca]

On Tue, 09 Oct 2012 15:02:02 -0400, Joe AutoDrill <auto...@yunx.com>
wrote:

>On 10/9/2012 2:42 PM, Ignoramus22161 wrote:
>> I am thinking of making a set up to drop a heavy weight (old forklift
>> counterweight) onto objects, such as truck cabs and file cabinets, to
>> flatten them in preparation for scrapping. That way they will take
>> less room in the scrap gondola.
>>
>> To drop that counterweight, it would need to be lifted with a
>> forklift, and then some sort of a release-under-tension would release
>> the object and it would fall.
>>
>> I have compressed air nearby if I wanted to make that mechanism
>> pneumatic.
>>
>> Any suggestion for something that could release an appx. 2-3 ton
>> weight?
>>
>> i
>>
>
>Maybe replace the forklift's cylinder with a cylinder that has very
>large ports on the "exhaust side" and install a solenoid or air powered
>"dump valve" to bypass the regular return track of the air/fluid?

Tilt fork forklift. Just tip the forks to dump the weight. Or a
hydraulic cyl to pull the pin out of a clevis on the cable holding the
weight.

[Jim Wilkins]

"Ignoramus22161" <ignoram...@NOSPAM.22161.invalid> wrote in
message news:xYKdnZ56qO2Z7enN...@giganews.com...

http://www.bobcat.com/attachments/drop_hammer
http://nfttu.blogspot.com/2008/02/catapult-and-trebuchet-triggers.html

[BQ340]

On 10/9/2012 2:42 PM, Ignoramus22161 wrote:

Ig, search for "Drop Test Clamp"

MikeB

--
Email is valid but not checked often

[Pete C.]

Debate religion and/or guns.

[Larry Jaques]

On Tue, 09 Oct 2012 13:42:12 -0500, Ignoramus22161
<ignoram...@NOSPAM.22161.invalid> wrote:

First question to pop into mind: How thick is your floor, Ig? ;)

Use pulleys and lift the weight by pressing down with the forks, set a
trip, then back up. Drop the weight when you trigger the release.

Wouldn't a nice plasma cutter work better and be more usable?

--
Energy and persistence alter all things.
--Benjamin Franklin

[Ignoramus22161]

On 2012-10-09, Pete C. <aux3....@snet.net> wrote:
> Yes, that's exactly what I said. You have a forklift lifting beam, do
> you not? All you need is a shackle setup to hang from that to hold the
> load. Something like a couple side plates of 1/2" steel with a top cross
> pin to hang from and a hydraulic cylinder on the side controlling a
> lower cross pin that goes through another steel plate that has a bottom
> hole for a regular shackle your load hangs from. Pull the pin with the
> hydraulics from the safety of the forklift and the load drops while the
> forklift mast stays put. Lower down safely, refit the hang plate, set
> the lock pin and repeat. Just a homemade version of the stunt shackles
> that have been linked. Those have hydraulic and pneumatic activation
> options as well. Perhaps find a good diagram of one of those and clone
> it more fully.

Yep, great description.

i

[jeff]

On Tue, 09 Oct 2012 13:42:12 -0500, Ignoramus22161
<ignoram...@NOSPAM.22161.invalid> wrote:

How high will this two/three ton weight be when you release it? I'm
thinking that the sudden release will cause the carriage to catapult
upwards possibly causing damage to aux hoses, maybe chain sheaves or
even the chains themselvs. Is this the same forklift that had the
worn works a while back?

jeff

[Gunner]

Forklifts were never designed for this sort of dynamic loading and
unloading.

You will destroy it inside of a month..and probably within weeks

Shrug

Gunner

"The best government is a benevolent tyranny tempered
by an occasional assassination." --Voltaire

[jcla...@gmail.com]

Google "3 ring release". If you don't mind doing some sewing you can DIY it, it's cheap, scales to just about any size, and if the rings are sized right it's dead reliable.

For another pennytech option, sounds like you have access to a good supply of scrap vehicles--use a truck axle, wheel, and brake (make sure that the axle is rated for the load you're dropping). Secure the axle to your lift, rig hydraulics to apply the brake, wrap your lift cable around the wheel, hook your load to the cable (or strap) set the brake, lift the whole shebang, and release the brake (make sure you have enough hose on the release valve to get to a safe distance).

[Bruce L. Bergman (munged human readable)]

On Sat, 13 Oct 2012 11:20:02 -0700, Gunner <gunne...@gmail.com>
wrote:

Don't think I said anything about this, but if you want to flatten
"little" things like desks and file cabinets, build your own version
of a Car Smasher.

Buy an old Cardboard Baler machine - cheap and easy. Place the file
cabinet or desk inside and hit the button, and it'll turn into a
Latke. I do NOT suggest sour cream or applesauce...

Or make your own and scale it way up, a couple chunks of 1" thick
plate for the mashing surfaces, and a pair of large-bore hydraulic
cylinders one at each end. A hoop of I-Beams between the two halves.

It can go straight up and down, or you can make it hinged - two hinged
leaves to meet in the middle and it can swallow a whole car at once.
Just remove the non-compressible items like the engine block and
transmission first.

And strip aluminum stuff like the radiator and AC cores, it's worth
more as clean aluminum.

Oh, and pull the battery and brake/clutch master cylinders too, or it
gets messy handling the pancake with sulphuric acid and DOT-3 (paint
stripper) dripping all over.

If you give a little pump a few minutes to cycle, it can do a lot of
smashing.

--<< Bruce >>--