A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner
and working at a 45 degree angle, puts a 510 pound load on the damper
_just_ to keep the gate still -- decelerating the gate takes even more
load, to the tune of 1700 pounds if you want to close the gate in one
second (that's assuming constant deceleration over 45 degrees in 1/2
second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--
www.wescottdesign.com

Tim Wescott wrote:

A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner
and working at a 45 degree angle, puts a 510 pound load on the damper
_just_ to keep the gate still -- decelerating the gate takes even more
load, to the tune of 1700 pounds if you want to close the gate in one
second (that's assuming constant deceleration over 45 degrees in 1/2
second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--
www.wescottdesign.com

I didn't read the previous thread, but if you are looking at those kind
of loads, I'd think you should be looking at a standard hydraulic
cylinder, tank and needle flow control valve.

On Feb 5, 8:03*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner
and working at a 45 degree angle, puts a 510 pound load on the damper
_just_ to keep the gate still -- decelerating the gate takes even more
load, to the tune of 1700 pounds if you want to close the gate in one
second (that's assuming constant deceleration over 45 degrees in 1/2
second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--www.wescottdesign.com

Tim, there is a place NW of Redmond that has a heavy steel gate with a
similar pivoting scheme. He has a chain drive an an electric motor to
raise and lower the thing. It is not 18 ft long, but is still pretty
heavy.

Could you construct a similar mechanism for your gate?

Paul

It seems a bit confusing, when you stated in an earlier post that the gate
is a scissors-type gate, and they're normally opened and closed horizontally
(not vertically).

I wouldn't consider lifting something of that length and weight to be a safe
(or practical) method of entry/exit.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Tim Wescott" wrote in message
...
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner
and working at a 45 degree angle, puts a 510 pound load on the damper
_just_ to keep the gate still -- decelerating the gate takes even more
load, to the tune of 1700 pounds if you want to close the gate in one
second (that's assuming constant deceleration over 45 degrees in 1/2
second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--
www.wescottdesign.com

On Feb 5, 11:03*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner
and working at a 45 degree angle, puts a 510 pound load on the damper
_just_ to keep the gate still -- decelerating the gate takes even more
load, to the tune of 1700 pounds if you want to close the gate in one
second (that's assuming constant deceleration over 45 degrees in 1/2
second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--www.wescottdesign.com

The damper on the forklift-sized fire door I was thinking of doesn't
support any weight at all, the hinges do that.

If this gate is statically balanced the only energy the dampener has
to absorb came from the person shutting it.

jsw

On Feb 5, 10:03*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner
and working at a 45 degree angle, puts a 510 pound load on the damper
_just_ to keep the gate still -- decelerating the gate takes even more
load, to the tune of 1700 pounds if you want to close the gate in one
second (that's assuming constant deceleration over 45 degrees in 1/2
second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--www.wescottdesign.com

I've seen cantilevered scissor gates with a supporting swivel caster
at the opening edge. Maybe adding a caster would provide enough drag
to prevent damage from slamming the gate. It would also lessen the
load on the pivot hinges.

"Tim Wescott" wrote in message
...
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner
and working at a 45 degree angle, puts a 510 pound load on the damper
_just_ to keep the gate still -- decelerating the gate takes even more
load, to the tune of 1700 pounds if you want to close the gate in one
second (that's assuming constant deceleration over 45 degrees in 1/2
second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--
www.wescottdesign.com



Years ago I saw a hydraulic cylinder with a cushion at the end of the
stroke. Instead of the cylinder bottoming out harshly the last bit of oil
would flow through a smaller orifice. One could use a flow control on both
stages to make the gate close at a slower rate near the end of the motion.

http://www.hydraulic-equipment-manuf...articles2.html

Steve

"Tim Wescott" wrote in message
...
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner
and working at a 45 degree angle, puts a 510 pound load on the damper
_just_ to keep the gate still -- decelerating the gate takes even more
load, to the tune of 1700 pounds if you want to close the gate in one
second (that's assuming constant deceleration over 45 degrees in 1/2
second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--
www.wescottdesign.com


Call this guy.

Mike Rotella
216-433-7766
http://www.control-line.com/motioncontrol.asp

Tell him I sent you. If he can't sell direct to you, I'll sell it to you at
my actual cost plus shipping.

....It's *NOT* a $50 device.

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com
Production Tapping: http://Production-Tapping-Equipment.com/
Flagship Site: http://www.Drill-N-Tap.com
VIDEOS: http://www.youtube.com/user/AutoDrill

V8013-R

On Fri, 05 Feb 2010 12:30:47 -0500, Wild_Bill wrote:

It seems a bit confusing, when you stated in an earlier post that the
gate is a scissors-type gate, and they're normally opened and closed
horizontally (not vertically).

I wouldn't consider lifting something of that length and weight to be a
safe (or practical) method of entry/exit.

And you call yourself "Wild" Bill...

First, it came that way, and second, it's counterbalanced with springs.
There's not much load out on the end of it, but if it's going fast when
it hits the stop it sure makes a bang.

--
www.wescottdesign.com

On Fri, 05 Feb 2010 09:10:18 -0800, wrote:

On Feb 5, 8:03Â*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top
corner and working at a 45 degree angle, puts a 510 pound load on the
damper _just_ to keep the gate still -- decelerating the gate takes
even more load, to the tune of 1700 pounds if you want to close the
gate in one second (that's assuming constant deceleration over 45
degrees in 1/2 second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--www.wescottdesign.com

Tim, there is a place NW of Redmond that has a heavy steel gate with a
similar pivoting scheme. He has a chain drive an an electric motor to
raise and lower the thing. It is not 18 ft long, but is still pretty
heavy.

Could you construct a similar mechanism for your gate?

Yabut. We're far enough out in the boonies that we lose power at least
once every winter, and the power line from the shop to the gate is hosed
and needs to be replaced -- I not only need a round tuit, I need to rent
a @#$% ditch witch _and_ figure out where the old line is.

So whatever else it does, it has to work manually, at least sometimes.

--
www.wescottdesign.com

On Fri, 05 Feb 2010 09:32:43 -0800, Jim Wilkins wrote:

On Feb 5, 11:03Â*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top
corner and working at a 45 degree angle, puts a 510 pound load on the
damper _just_ to keep the gate still -- decelerating the gate takes
even more load, to the tune of 1700 pounds if you want to close the
gate in one second (that's assuming constant deceleration over 45
degrees in 1/2 second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--www.wescottdesign.com

The damper on the forklift-sized fire door I was thinking of doesn't
support any weight at all, the hinges do that.

If this gate is statically balanced the only energy the dampener has to
absorb came from the person shutting it.

And I have very energetic children with very undamped enthusiasm.

The gate is partially balanced with springs, but you can shut (or open)
it by pulling it just over center then letting go -- it gets up quite a
head of steam by the time it hits a stop.

--
www.wescottdesign.com

On Feb 5, 2:43*pm, Tim Wescott wrote:
On Fri, 05 Feb 2010 09:10:18 -0800, wrote:
On Feb 5, 8:03*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top
corner and working at a 45 degree angle, puts a 510 pound load on the
damper _just_ to keep the gate still -- decelerating the gate takes
even more load, to the tune of 1700 pounds if you want to close the
gate in one second (that's assuming constant deceleration over 45
degrees in 1/2 second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one that'll
support a ton?

--www.wescottdesign.com

Tim, there is a place NW of Redmond that has a heavy steel gate with a
similar pivoting scheme. He has a chain drive an an electric motor to
raise and lower the thing. It is not 18 ft long, but is still pretty
heavy.

Could you construct a similar mechanism for your gate?

Yabut. *We're far enough out in the boonies that we lose power at least
once every winter, and the power line from the shop to the gate is hosed
and needs to be replaced -- I not only need a round tuit, I need to rent
a @#$% ditch witch _and_ figure out where the old line is.

So whatever else it does, it has to work manually, at least sometimes.

--www.wescottdesign.com

Just power up the old line and dig crossways to it. You'll know as
soon as you hit it.
Karl

On Sat, 06 Feb 2010 00:50:14 -0800, wrote:

On Feb 5, 2:43Â*pm, Tim Wescott wrote:
On Fri, 05 Feb 2010 09:10:18 -0800, wrote:
On Feb 5, 8:03Â*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top
corner and working at a 45 degree angle, puts a 510 pound load on
the damper _just_ to keep the gate still -- decelerating the gate
takes even more load, to the tune of 1700 pounds if you want to
close the gate in one second (that's assuming constant deceleration
over 45 degrees in 1/2 second).

(I decided I didn't want to close it that fast).

Anyone who suggested a fire-door damper -- where can I find one
that'll support a ton?

--www.wescottdesign.com

Tim, there is a place NW of Redmond that has a heavy steel gate with
a similar pivoting scheme. He has a chain drive an an electric motor
to raise and lower the thing. It is not 18 ft long, but is still
pretty heavy.

Could you construct a similar mechanism for your gate?

Yabut. Â*We're far enough out in the boonies that we lose power at least
once every winter, and the power line from the shop to the gate is
hosed and needs to be replaced -- I not only need a round tuit, I need
to rent a @#$% ditch witch _and_ figure out where the old line is.

So whatever else it does, it has to work manually, at least sometimes.

--www.wescottdesign.com

Just power up the old line and dig crossways to it. You'll know as soon
as you hit it.
Karl

Aw dangit -- that's such a good idea, but its got a dead short that blows
the breaker immediately.

But thanks for the help -- maybe next time I'll be able to use it.

--
www.wescottdesign.com

On Feb 5, 4:43*pm, Tim Wescott wrote:

Yabut. *We're far enough out in the boonies that we lose power at least
once every winter, and the power line from the shop to the gate is hosed
and needs to be replaced -- I not only need a round tuit, I need to rent
a @#$% ditch witch _and_ figure out where the old line is.

So whatever else it does, it has to work manually, at least sometimes.

--www.wescottdesign.com



Ok, I do understand about the round tuit. So lets convert the
mechanism to a manual cranking system. Let the kids crank it up and
crank it down.


Paul

You don't really need a mechanism to follow the entire range of motion, you
just need a snubber that effects/engages (maybe) the last 4-10" of closing.

A hydraulic cylinder with a built-in snubber would probably be more
difficult to locate and/or more expensive.

A snubber could be a common cylinder with a light duty spring to extend the
ram, and a needle/restrictor valve to adjust how fast the ram can be pushed
into the cylinder.
The check valve in parallel with the restrictor would be optional. The
spring will slowly extend the ram.

But it's still a scissors gate.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Tim Wescott" wrote in message
...
On Fri, 05 Feb 2010 12:30:47 -0500, Wild_Bill wrote:

It seems a bit confusing, when you stated in an earlier post that the
gate is a scissors-type gate, and they're normally opened and closed
horizontally (not vertically).

I wouldn't consider lifting something of that length and weight to be a
safe (or practical) method of entry/exit.

And you call yourself "Wild" Bill...

First, it came that way, and second, it's counterbalanced with springs.
There's not much load out on the end of it, but if it's going fast when
it hits the stop it sure makes a bang.

--
www.wescottdesign.com