I am installing electric openers on two new (sectional) garage doors.
The doors are top-of-the-line models from Overhead Door, dealer
installed. I have always understood that the weight of the garage
doors must be counter balanced by the springs. Makes sense.

These doors have a top panel with insulated glass. While the top panel
is significantly heavier than all the others, it is also the weakest;
therefore, as shown in the instructions, a metal reinforcement plate
is added for attaching the opener and a continuous angle iron
stiffener is added completely across the top of the panel to prevent
the panel from flexing.

Trouble is, how can one get such a door properly balanced? When the
recommended tension springs are installed and adjusted such that the
door stays down and can be lifted without much effort, the door takes
off and must be held back as the top panel moves out of the vertical
track onto the overhead (horizontal) track section! Makes sense, since
the spring has a constant force rate whereas the door does not.

I see potential safety problems with this situation regardless of
whether the door is operated manually or with an electric opener (load
sensitivity, reversing and such).

In an ideal situation balance would mean "throughout the entire
range"; in the example given in the instruction booklet, balance is
check at the halfway point. I suppose I could add weight to the bottom
of the door and go with heavier springs to obtain balance throughout
the range, but when am I close enough?

If the door balances at the half-way point but it takes X pounds lift
it from the closed position and Y pounds to pull it down, what are
safe/acceptable values for X and Y with the electric door opener?

Is there an engineer at Chamberlain that is willing to go on record
here? - Thanks!

HKEK writes:

If the door balances at the half-way point but it takes X pounds lift
it from the closed position and Y pounds to pull it down, what are
safe/acceptable values for X and Y with the electric door opener?

That's a good question, but in practice 10 or 20 lbs is about as close as
you can get in many situations. If the mass of your door is uneven across
the panels as you describe, the force will vary at least as much as the
panel mass varies. For example, if you have an extra 20 lbs on the top
panel, it effectively disappears when the panel goes horizontal. The
standard residential door torsion spring mechanism is based on door lift
weight being proportionate to lift distance, since the door turns
proportionately horizontal. This in turn assumes the door is approximately
homogenous, not heavier in some panels than others. Violating that
assumption with a heavy panel cannot be compensated for by spring
adjustment. You have to make the other panels just as heavy, and install
heavier spring(s) for the whole works.

http://www.truetex.com/garage.htm

HKEK wrote:
I am installing electric openers on two new (sectional) garage doors.
The doors are top-of-the-line models from Overhead Door, dealer
installed. I have always understood that the weight of the garage
doors must be counter balanced by the springs. Makes sense.

These doors have a top panel with insulated glass. While the top panel
is significantly heavier than all the others, it is also the weakest;
therefore, as shown in the instructions, a metal reinforcement plate
is added for attaching the opener and a continuous angle iron
stiffener is added completely across the top of the panel to prevent
the panel from flexing.

Trouble is, how can one get such a door properly balanced? When the
recommended tension springs are installed and adjusted such that the
door stays down and can be lifted without much effort, the door takes
off and must be held back as the top panel moves out of the vertical
track onto the overhead (horizontal) track section! Makes sense, since
the spring has a constant force rate whereas the door does not.

I see potential safety problems with this situation regardless of
whether the door is operated manually or with an electric opener (load
sensitivity, reversing and such).

In an ideal situation balance would mean "throughout the entire
range"; in the example given in the instruction booklet, balance is
check at the halfway point. I suppose I could add weight to the bottom
of the door and go with heavier springs to obtain balance throughout
the range, but when am I close enough?

If the door balances at the half-way point but it takes X pounds lift
it from the closed position and Y pounds to pull it down, what are
safe/acceptable values for X and Y with the electric door opener?

Is there an engineer at Chamberlain that is willing to go on record
here? - Thanks!

Biggest safety concern is too much weight in the downward position so it
falls. If it is a little strong when it is balanced at the midway point
for your taste, let off a little so it's more nearly at the 3/4-closed
point, but I'd not go past that.

An opener won't have any problem either way, it's only when it's
operated manually you have a real issue...

--

In article . com, HKEK wrote:
I am installing electric openers on two new (sectional) garage doors.
The doors are top-of-the-line models from Overhead Door, dealer
installed. I have always understood that the weight of the garage
doors must be counter balanced by the springs. Makes sense.

These doors have a top panel with insulated glass. While the top panel
is significantly heavier than all the others, it is also the weakest;
therefore, as shown in the instructions, a metal reinforcement plate
is added for attaching the opener and a continuous angle iron
stiffener is added completely across the top of the panel to prevent
the panel from flexing.

I'm surprised the weight difference is sufficient to create a
serious problem. Is it just the glass? Or is the extra metal
reinforcement creating (or adding to) the problem?

I can only suggest adding some extra weight to the bottom of
the door in order to achieve balance.

I will need to replace my own garage doors in the next year
or two and this seems to be another good reason to pass on
the windows! The others include cost and a possible break-in
vulnerability as discussed in a another recent thread. The
glass can help the asthetics but the disadvantages are starting
to pile up!


--
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~|
| Malcolm Hoar "The more I practice, the luckier I get". |
| Gary Player. |
| http://www.malch.com/ Shpx gur PQN. |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~

"Richard J Kinch" wrote in message
. ..
HKEK writes:

If the door balances at the half-way point but it takes X pounds lift
it from the closed position and Y pounds to pull it down, what are
safe/acceptable values for X and Y with the electric door opener?

That's a good question, but in practice 10 or 20 lbs is about as close as
you can get in many situations. If the mass of your door is uneven across
the panels as you describe, the force will vary at least as much as the
panel mass varies. For example, if you have an extra 20 lbs on the top
panel, it effectively disappears when the panel goes horizontal. The
standard residential door torsion spring mechanism is based on door lift
weight being proportionate to lift distance, since the door turns
proportionately horizontal. This in turn assumes the door is
approximately
homogenous, not heavier in some panels than others. Violating that
assumption with a heavy panel cannot be compensated for by spring
adjustment. You have to make the other panels just as heavy, and install
heavier spring(s) for the whole works.

http://www.truetex.com/garage.htm

Wow! So much detailed info .. bookmarking this for a raining day to
read. Thanks Richard.

On Wed, 17 Oct 2007 12:41:05 -0700, "** Frank **"
wrote:


"Richard J Kinch" wrote in message
...
HKEK writes:

http://www.truetex.com/garage.htm

Wow! So much detailed info .. bookmarking this for a raining day to
read. Thanks Richard.


The garage door link came at a good time for me :-))

I've been reading Richard's pages on pool repair/remodel.

http://www.truetex.com/pool.htm


--
Oren

Hofstadter's Law - It [a task] always takes longer than you expect, even when you take into account Hofstadter's Law.

"Oren" wrote in message
...
On Wed, 17 Oct 2007 12:41:05 -0700, "** Frank **"
wrote:


"Richard J Kinch" wrote in message
1...
HKEK writes:

http://www.truetex.com/garage.htm

Wow! So much detailed info .. bookmarking this for a raining day to
read. Thanks Richard.


The garage door link came at a good time for me :-))

I've been reading Richard's pages on pool repair/remodel.

http://www.truetex.com/pool.htm


--
Oren

Hofstadter's Law - It [a task] always takes longer than you expect, even
when you take into account Hofstadter's Law.

Thanks Oren, another good one from Richard.

On Oct 17, 12:08 pm, (Malcolm Hoar) wrote:


I will need to replace my own garage doors in the next year
or two and this seems to be another good reason to pass on
the windows! The others include cost and a possible break-in
vulnerability as discussed in a another recent thread. The
glass can help the asthetics but the disadvantages are starting
to pile up!

Don't know what other thread you're referring to regarding
vulnerabilities, but our HOA recently sent out a news letter with
security tips. One that I never thought of involved removing the rope
from the mechanism that disengages the opener trolley from the track.
When the door is closed, imagine how close that rope is to the door.
Now imagine how easy it would be to snag that rope from the outside
and disengage the trolley. Don't need windows in the door to do that.
Removed the rope from my door the same day. If I ever need to
disengage it, I'll grab a stepladder.

Jerry

HKEK wrote:
I am installing electric openers on two new (sectional) garage doors.
The doors are top-of-the-line models from Overhead Door, dealer
installed. I have always understood that the weight of the garage
doors must be counter balanced by the springs. Makes sense.


That's why you need a 1/2hp motor.

If the springs exactly and perfectly balanced the load, you could lift the
door with the motor from your bedside clock.

"Jerry" wrote in message
oups.com...
On Oct 17, 12:08 pm, (Malcolm Hoar) wrote:


I will need to replace my own garage doors in the next year
or two and this seems to be another good reason to pass on
the windows! The others include cost and a possible break-in
vulnerability as discussed in a another recent thread. The
glass can help the asthetics but the disadvantages are starting
to pile up!

Don't know what other thread you're referring to regarding
vulnerabilities, but our HOA recently sent out a news letter with
security tips. One that I never thought of involved removing the rope
from the mechanism that disengages the opener trolley from the track.
When the door is closed, imagine how close that rope is to the door.
Now imagine how easy it would be to snag that rope from the outside
and disengage the trolley. Don't need windows in the door to do that.
Removed the rope from my door the same day. If I ever need to
disengage it, I'll grab a stepladder.

Jerry


I don't know what other thread he was referring to either. What a difference
windows make, so much light across my three car garage area. I'll put
windows on every door, including the rental units. Its much easier to crash
through the front door or bump the lockset than fool around with the garage
window. Living in a safe neighborhood helps.

I had one opener that would automatically open the garage door if someone
lifts the door a little bid from the outside. That one didn't have windows.
LOL

In article .com, Jerry wrote:

Don't know what other thread you're referring to regarding
vulnerabilities, but our HOA recently sent out a news letter with
security tips. One that I never thought of involved removing the rope
from the mechanism that disengages the opener trolley from the track.
When the door is closed, imagine how close that rope is to the door.
Now imagine how easy it would be to snag that rope from the outside
and disengage the trolley. Don't need windows in the door to do that.
Removed the rope from my door the same day. If I ever need to
disengage it, I'll grab a stepladder.

Yup, that was the issue raised here, last week, I think.

I am neverthless amazed that an HOA would advocate removing
or disabling what is, in fact, a safety device. Their
insurers would probably go ballistic.

Now, I'm not sure those ropes have saved a whole ton of
lives. But it's a can of worms when it comes to legal
liabilities.

I'd keep that rope safe and reinstall it if or when you
sell the property.


--
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~|
| Malcolm Hoar "The more I practice, the luckier I get". |
| Gary Player. |
| http://www.malch.com/ Shpx gur PQN. |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~

On Wed, 17 Oct 2007 21:23:01 GMT, (Malcolm Hoar)
wrote:

In article .com, Jerry wrote:

Don't know what other thread you're referring to regarding
vulnerabilities, but our HOA recently sent out a news letter with
security tips. One that I never thought of involved removing the rope
from the mechanism that disengages the opener trolley from the track.
When the door is closed, imagine how close that rope is to the door.
Now imagine how easy it would be to snag that rope from the outside
and disengage the trolley. Don't need windows in the door to do that.
Removed the rope from my door the same day. If I ever need to
disengage it, I'll grab a stepladder.

Yup, that was the issue raised here, last week, I think.

In that thread, was the first ever mention about a garage door breach
via the rope. I gave thanks to the poster as it had not been mentioned
in security tips I've read in the past.

I am neverthless amazed that an HOA would advocate removing
or disabling what is, in fact, a safety device. Their
insurers would probably go ballistic.

The HOA is better served, by just collecting fees and not giving
advice contrary to safety.

Now, I'm not sure those ropes have saved a whole ton of
lives. But it's a can of worms when it comes to legal
liabilities.

I'd keep that rope safe and reinstall it if or when you
sell the property.

My ropes will stay in place, as is. I have to further examine one door
as I _believe_ it is on a GFCI circuit. I don't think that is safe.

The rope can get one out of the house, when that is the escape route.


--
Oren

...through the use of electrical or duct tape, achieve the configuration in the photo..

Is this a torsion system or open tension springs. I'd say you need a
torsion system if it's not already. It sounds like your a bit too tight to
me. Although the action you describe is fairly normal. You'll also notice
the drums the cables wind up on are tapered. They are designed to give more
lift at first and be weaker as the door goes up. I'd say if you get your
reinforcements on, then balance it to the point it takes about 10-20 lbs of
lift to get it started, you'll be ok.


steve (installed a few, adjusted a few dozen)

"HKEK" wrote in message
ups.com...
I am installing electric openers on two new (sectional) garage doors.
The doors are top-of-the-line models from Overhead Door, dealer
installed. I have always understood that the weight of the garage
doors must be counter balanced by the springs. Makes sense.

These doors have a top panel with insulated glass. While the top panel
is significantly heavier than all the others, it is also the weakest;
therefore, as shown in the instructions, a metal reinforcement plate
is added for attaching the opener and a continuous angle iron
stiffener is added completely across the top of the panel to prevent
the panel from flexing.

Trouble is, how can one get such a door properly balanced? When the
recommended tension springs are installed and adjusted such that the
door stays down and can be lifted without much effort, the door takes
off and must be held back as the top panel moves out of the vertical
track onto the overhead (horizontal) track section! Makes sense, since
the spring has a constant force rate whereas the door does not.

I see potential safety problems with this situation regardless of
whether the door is operated manually or with an electric opener (load
sensitivity, reversing and such).

In an ideal situation balance would mean "throughout the entire
range"; in the example given in the instruction booklet, balance is
check at the halfway point. I suppose I could add weight to the bottom
of the door and go with heavier springs to obtain balance throughout
the range, but when am I close enough?

If the door balances at the half-way point but it takes X pounds lift
it from the closed position and Y pounds to pull it down, what are
safe/acceptable values for X and Y with the electric door opener?

Is there an engineer at Chamberlain that is willing to go on record
here? - Thanks!

On Oct 17, 3:06 pm, Oren wrote:
On Wed, 17 Oct 2007 21:23:01 GMT, (Malcolm Hoar)
wrote:

In article .com, Jerry wrote:

Don't know what other thread you're referring to regarding
vulnerabilities, but our HOA recently sent out a news letter with
security tips. One that I never thought of involved removing the rope
from the mechanism that disengages the opener trolley from the track.
When the door is closed, imagine how close that rope is to the door.
Now imagine how easy it would be to snag that rope from the outside
and disengage the trolley. Don't need windows in the door to do that.
Removed the rope from my door the same day. If I ever need to
disengage it, I'll grab a stepladder.

Yup, that was the issue raised here, last week, I think.

In that thread, was the first ever mention about a garage door breach
via the rope. I gave thanks to the poster as it had not been mentioned
in security tips I've read in the past.


Yep, our neighborhood had a rash of garage/house breakins where that
was the method of entry. They mentioned removing the rope as a means
of securing the garage door as a vulnerable entry point, but they
obviously did not consider or mention the safety aspects. I may have
to reconsider reattaching that rope.


The HOA is better served, by just collecting fees and not giving
advice contrary to safety.


They do a REAL good job on the collecting fees part. Closely followed
by sending letters telling you to clean up your weeds. G


The rope can get one out of the house, when that is the escape route.


Yeah, I didn't consider that aspect. If you have a fire in the garage
that has disabled the door opener, and the garage door is your only
way out, I guess you wouldn't want to take the time, in the dark and
smoke and fire, to look for your stepladder so you could disengage the
trolley from the track.

Jerry

Steve Barker LT writes:

You'll also notice the drums the cables wind up on are tapered.

Standard residential door drums are not tapered. Torque declines as the
torsion spring unwinds. So does the door lift weight as it bends
horizontal.

They are designed to
give more lift at first and be weaker as the door goes up.

Tapered drums are used to produce *constant* lift, such as for a straight-
up hangar door.

I am installing electric openers on two new (sectional) garage doors.
The doors are top-of-the-line models from Overhead Door, dealer
installed.

Since OH Doors (dealer installed) are warranteed, I d take a guess at it and
conclude THEY will set them up the way they re supposed to be.
Then I d attach the electric opener and push the button. I had 3 they put
in at our last house and this method worked fine for me with the Sears 1/2
HP openers I put in.

On Oct 17, 7:18 pm, Jerry wrote:
On Oct 17, 3:06 pm, Oren wrote:





On Wed, 17 Oct 2007 21:23:01 GMT, (Malcolm Hoar)
wrote:

In article .com, Jerry wrote:

Don't know what other thread you're referring to regarding
vulnerabilities, but our HOA recently sent out a news letter with
security tips. One that I never thought of involved removing the rope
from the mechanism that disengages the opener trolley from the track.
When the door is closed, imagine how close that rope is to the door.
Now imagine how easy it would be to snag that rope from the outside
and disengage the trolley. Don't need windows in the door to do that.
Removed the rope from my door the same day. If I ever need to
disengage it, I'll grab a stepladder.

Yup, that was the issue raised here, last week, I think.

In that thread, was the first ever mention about a garage door breach
via the rope. I gave thanks to the poster as it had not been mentioned
in security tips I've read in the past.

Yep, our neighborhood had a rash of garage/house breakins where that
was the method of entry. They mentioned removing the rope as a means
of securing the garage door as a vulnerable entry point, but they
obviously did not consider or mention the safety aspects. I may have
to reconsider reattaching that rope.



The HOA is better served, by just collecting fees and not giving
advice contrary to safety.

They do a REAL good job on the collecting fees part. Closely followed
by sending letters telling you to clean up your weeds. G



The rope can get one out of the house, when that is the escape route.

Yeah, I didn't consider that aspect. If you have a fire in the garage
that has disabled the door opener, and the garage door is your only
way out, I guess you wouldn't want to take the time, in the dark and
smoke and fire, to look for your stepladder so you could disengage the
trolley from the track.

Jerry- Hide quoted text -

- Show quoted text -


Maybe I'm missing something here, but I don't see the opener
disconnect as being a major security vulnerability. And the poster
said you don't need windows in the door for it to be a security
issue? Now, that I totally don't get. Without a window, you'd have
to knock out a garage door panel to get to the rope. That assumes of
course, the garage door has an opener. And if you;re going to take
out a panel, why not just kick out one at ground level and crawl
through, where you don;'t care if it has an opener or not?

And then, if you're talking about breaking out a garage door window to
get to the rope release, how secure are any other doors/windows? If
you have a sliding glass door, or first level window, you can break
those for entry easily. I can see this as a security issue if you
have the rest of the house well secured and live in an area where
break-ins are common, but for the typical house, it;s a non issue.

Maybe I'm missing something here, but I don't see the opener
disconnect as being a major security vulnerability. And the poster
said you don't need windows in the door for it to be a security
issue? Now, that I totally don't get. Without a window, you'd have
to knock out a garage door panel to get to the rope. That assumes of
course, the garage door has an opener. And if you;re going to take
out a panel, why not just kick out one at ground level and crawl
through, where you don;'t care if it has an opener or not?

And then, if you're talking about breaking out a garage door window to
get to the rope release, how secure are any other doors/windows? If
you have a sliding glass door, or first level window, you can break
those for entry easily. I can see this as a security issue if you
have the rest of the house well secured and live in an area where
break-ins are common, but for the typical house, it;s a non issue.


Easier just to steal the opener code or bump the door lock. I see break ins
through doors and windows, no garage doors yet - maybe just too slow.

In article , "** Frank **" wrote:
Easier just to steal the opener code or bump the door lock. I see break ins
through doors and windows, no garage doors yet - maybe just too slow.

Professional house breakers use the same MO on house
after house. If this method of entry is popular in
your neighborhood, it would be prudent to be concerned.
Other posters have indicated this is a favored entry
point in their localities. Apparently, not in all
communities and, AFAIK, not in mine. But if you live
in an at-risk area it would be sensible to take
precautions.

Personally, I wouldn't recommend removing the emergency
release rope -- you might just need it one day. But
you might make some adjustments that would make it
really, really hard for some Bad Guy to activate the
thing from the outside.

--
|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~|
| Malcolm Hoar "The more I practice, the luckier I get". |
| Gary Player. |
| http://www.malch.com/ Shpx gur PQN. |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~