T-hangar's bi-fold door: Convert to a motorized opening door?

[Peter R.]

Here's a silly question: Is there any way to convert a t-hangar's
manually opening bi-fold door to a motorized one?

I just rented a t-hangar that uses a circular chain hanging off a large
pulley near the top of the hangar to control the door. The chain must
be pulled thirty to forty times to fully open or close the bi-fold door.

Perhaps some type of conversion to an automatic garage door opener?

Has anyone ever done anything like this?

--
Peter

[Newps]

Peter R. wrote:

> Here's a silly question: Is there any way to convert a t-hangar's
> manually opening bi-fold door to a motorized one?
>
> I just rented a t-hangar that uses a circular chain hanging off a large
> pulley near the top of the hangar to control the door. The chain must
> be pulled thirty to forty times to fully open or close the bi-fold door.
>
> Perhaps some type of conversion to an automatic garage door opener?
>
> Has anyone ever done anything like this?

Or ditch the stupid crappy bi fold completely and get a hydroswing to
really go first class.

[Jay Honeck]

> Here's a silly question: Is there any way to convert a t-hangar's
> manually opening bi-fold door to a motorized one?

If you figure this one out, please let us all know. Our hangar is over 40
years old, and it would sure be nice to just push a button to open the door.

Of course, you'd put my kids out of business. (We pay them 25 cents for
each opening...)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[G.R. Patterson III]

"Peter R." wrote:
>
> Perhaps some type of conversion to an automatic garage door opener?

Garage door openers drive a sprocket that operates a circular chain. Some of the
older units had a block on the chain that tripped a switch when the door was raised.
This block could be adjusted to fine-tune the system. My Genie units do not have
this. I assume (but do not know) that they simply pull the chain for a fixed distance
(most doors are 7' tall).

So. Measure the distance you have to pull your chain to open the hangar door. Work
out the ratio between that and 7'. Rig a reduction gear out of two appropriately
sized pulleys and a belt and drive that from a chain driven by a garage door opener.
You can probably use your existing chain pulley as one pulley in the reduction gear
and mount the whole thing high on the wall.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

[Doordoc]

Peter R. > wrote in message >...
> Here's a silly question: Is there any way to convert a t-hangar's
> manually opening bi-fold door to a motorized one?
>
> I just rented a t-hangar that uses a circular chain hanging off a large
> pulley near the top of the hangar to control the door. The chain must
> be pulled thirty to forty times to fully open or close the bi-fold door.
>
> Perhaps some type of conversion to an automatic garage door opener?
>
> Has anyone ever done anything like this?

This site will give you an idea of how some mfg's do it
http://bifold.com/safety/electrical.cfm

Doordoc
www.DoorsAndOpeners.com

Have seen many doors like this in our area but I personally have never
installed or worked on this type of door.

[Doordoc]

Peter R. > wrote in message >...
> Here's a silly question: Is there any way to convert a t-hangar's
> manually opening bi-fold door to a motorized one?
>
> I just rented a t-hangar that uses a circular chain hanging off a large
> pulley near the top of the hangar to control the door. The chain must
> be pulled thirty to forty times to fully open or close the bi-fold door.
>
> Perhaps some type of conversion to an automatic garage door opener?
>
> Has anyone ever done anything like this?

This site will give you an idea of how some mfg's do it
http://bifold.com/safety/electrical.cfm

Doordoc
www.DoorsAndOpeners.com

Have seen many doors like this in our area but I personally have never
installed or worked on this type of door.

[Peter R.]

G.R. Patterson III wrote:

> Garage door openers drive a sprocket that operates a circular chain. Some of the
> older units had a block on the chain that tripped a switch when the door was raised.
> This block could be adjusted to fine-tune the system. My Genie units do not have
> this. I assume (but do not know) that they simply pull the chain for a fixed distance
> (most doors are 7' tall).
>
> So. Measure the distance you have to pull your chain to open the hangar door. Work
> out the ratio between that and 7'. Rig a reduction gear out of two appropriately
> sized pulleys and a belt and drive that from a chain driven by a garage door opener.
> You can probably use your existing chain pulley as one pulley in the reduction gear
> and mount the whole thing high on the wall.

Thanks, George. I might just try this project.

--
Peter

[Peter R.]

Jay Honeck wrote:

> Of course, you'd put my kids out of business. (We pay them 25 cents for
> each opening...)

25 cents? Wow, that cheap labor. :)

--
Peter

[Peter Duniho]

"G.R. Patterson III" > wrote in message
...
> Garage door openers drive a sprocket that operates a circular chain.
> Some of the older units had a block on the chain that tripped a
> switch when the door was raised. This block could be adjusted to
> fine-tune the system. My Genie units do not have this. I assume
> (but do not know) that they simply pull the chain for a fixed
> distance (most doors are 7' tall).

They have essentially the same system, except that the block has been
replaced by an analog inside the opener. A worm drive moves a block back
and forth, that triggers switches at either end of the range of movement.
One end tells the opener when it's done opening, the other tells it when
it's done closing.

As with the older units, the end result is that the opener simply pulls the
chain for a fixed distance. In the case of the older units, the distance is
set by the block, in the newer units this is adjustable (within a small
range) by a setting that affects the exact position of the ends of the
internal mechanism.

> So. Measure the distance you have to pull your chain to open the
> hangar door. Work out the ratio between that and 7'. Rig a reduction
> gear out of two appropriately sized pulleys and a belt and drive
> that from a chain driven by a garage door opener.

Some problems I see with that:

* You will want to ensure that the mechanism inside the opener is up to
the task. The garage door opener I've had open has a nylon worm drive to
turn the main sprocket for the chain. It wears out even under normal garage
use, with a counter-spring to help reduce the forces involved. Even if the
hangar door is counter-weighted somehow, there may be more friction with the
larger door. It may be a lot to ask of little plastic pieces.

* The opener has a motor speed sensor that tells it when the thing is
getting bogged down too much. Because its main purpose is to avoid someone
getting crushed by the door, it's very sensitive. The sensitivity can be
adjusted somewhat, but probably not enough to account for a significant
difference in force required.

* To make matters worse, in combination with the above issues, a
reduction gear that increases the effective travel of the opener is
necessarily going to increase the force that the opener is required to
provide.

* Finally, using a belt and pulley system for the reduction gear may
result in the belt slipping. If it slips only at the very beginning of the
door movement, and it slips exactly the same amount when opening as when
closing, this might be okay. But otherwise, it will throw the system out of
adjustment.

I would say that with a large enough (i.e. expensive enough) garage door
opener, the above issues may not be a problem. But then you may start
finding that you'd have been better off just designing a custom-made opener
mechanism from scratch. Electric motors aren't that expensive, and the rest
is just a sprocket, switches and wiring, and possibly a new chain (depending
on what kind of "chain" is currently used with the manual opening system).

Pete

[Doordoc]

Peter R. > wrote in message >...
> G.R. Patterson III wrote:
>
> > Garage door openers drive a sprocket that operates a circular chain. Some of the
> > older units had a block on the chain that tripped a switch when the door was raised.
> > This block could be adjusted to fine-tune the system. My Genie units do not have
> > this. I assume (but do not know) that they simply pull the chain for a fixed distance
> > (most doors are 7' tall).
> >
> > So. Measure the distance you have to pull your chain to open the hangar door. Work
> > out the ratio between that and 7'. Rig a reduction gear out of two appropriately
> > sized pulleys and a belt and drive that from a chain driven by a garage door opener.
> > You can probably use your existing chain pulley as one pulley in the reduction gear
> > and mount the whole thing high on the wall.
>
> Thanks, George. I might just try this project.

Actually many residential garage doors will open up a 10' high door
when they have the right length rail & chain. So if your door is 10'
tall you do not need to change the reduction at all, but if your door
is taller then 10' you would have to change the reduction. However if
you change the reduction very much (depends on door height) you are
also going to increase the speed that the door opens which may result
in an unsafe operating condition & is also going to put more wear &
tear on the door. Residential garage door openers are not designed for
this type of use & for your own safety is not something I would
personally recommend doing.

Doordoc

[G.R. Patterson III]

Doordoc wrote:
>
> So if your door is 10'
> tall you do not need to change the reduction at all, but if your door
> is taller then 10' you would have to change the reduction.

Since this is a folding door, it's not a matter of the door height at all. It's
purely a matter of how much of the chain on his door he needs to pull to raise it
versus how much chain the opener pulls before it hits its limit switch. If the limit
switch on the GDO is adjustable, there's no need for a reduction mechanism at all.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

[G.R. Patterson III]

Peter Duniho wrote:
>
> * You will want to ensure that the mechanism inside the opener is up to
> the task. The garage door opener I've had open has a nylon worm drive to
> turn the main sprocket for the chain. It wears out even under normal garage
> use, with a counter-spring to help reduce the forces involved. Even if the
> hangar door is counter-weighted somehow, there may be more friction with the
> larger door. It may be a lot to ask of little plastic pieces.

I had assumed from the description that the opening mechanism on the hangar door is
similar to others with which I've dealt. In those, the chain is operated by hand and
requires only negligible force. It drives a gear that operates the actual opening
mechanism. Usually the gearing is such that the chain must be pulled a considerable
distance to raise the door, which is what results in it being so easy to pull around.
The doors with which I am familiar would require less from the GDO than normal garage
doors would require.

As for wearing out, there was a Craftsman unit in the house I used to own when I
bought it in 1988. It was still working well when I sold the house in 2001. The two
Genie units in my existing home were in it when we bought in 2000 and are doing just
fine so far. No telling how old they are. I installed one for a friend back in 1985
and it's still in service. The ones with which I've dealt are pretty bulletproof. You
might want to change brands the next time yours goes.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

[Morgans]

"Doordoc" > wrote in message
om...
> Peter R. > wrote in message
>...
> > G.R. Patterson III wrote:
> >
> > > Garage door openers drive a sprocket that operates a circular chain.
Some of the
> > > older units had a block on the chain that tripped a switch when the
door was raised.
> > > This block could be adjusted to fine-tune the system. My Genie units
do not have
> > > this. I assume (but do not know) that they simply pull the chain for a
fixed distance
> > > (most doors are 7' tall).
> > >
> > > So. Measure the distance you have to pull your chain to open the
hangar door. Work
> > > out the ratio between that and 7'. Rig a reduction gear out of two
appropriately
> > > sized pulleys and a belt and drive that from a chain driven by a
garage door opener.
> > > You can probably use your existing chain pulley as one pulley in the
reduction gear
> > > and mount the whole thing high on the wall.
> >
> > Thanks, George. I might just try this project.
>
> Actually many residential garage doors will open up a 10' high door
> when they have the right length rail & chain. So if your door is 10'
> tall you do not need to change the reduction at all, but if your door
> is taller then 10' you would have to change the reduction. However if
> you change the reduction very much (depends on door height) you are
> also going to increase the speed that the door opens which may result
> in an unsafe operating condition & is also going to put more wear &
> tear on the door. Residential garage door openers are not designed for
> this type of use & for your own safety is not something I would
> personally recommend doing.
>
> Doordoc

I would say, that a proper application of a residential opener could be
safe, and reliable. It would take some doing.

Gear the output of the opener, so that the door moves at a speed comparable
to how fast the door would move, if it were being opened manually. This
would mean a much longer cycle time than the electric opener was designed
for, so the original limit switches would not work. A Craftsman (Sears)
opener, of older design had built in limit switches run by a threaded rod,
to control the start and stop locations, and thus times. Keep the concept,
but instead of pushing the switches using the built in threaded rod,
relocate new switches, so the doors physically push on the new switches to
start, stop, and reverse the movement.

I have my show sawdust system run by an old opener. The only parts I had to
buy were two new limit switches, and a bit of wire. The two new switches
are actuated by the threaded rod, but the original switches still start and
stop the opener. The new switches hold in the coil for the magnetic starter
circuit, and still let the pushbutton stations operate normally when the
remote is not being used.

Good luck. Contact me, if you want to make a go at it. I do happen to have
one more old opener on hand, :-))
--
Jim in NC


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[Peter Duniho]

"G.R. Patterson III" > wrote in message
...
> [...] The ones with which I've dealt are pretty bulletproof. You
> might want to change brands the next time yours goes.

The one I had to fix is a Craftsman. I don't know how old it is.

As far as the gearing/load issue goes: a certain amount of work (force over
distance) will be required to raise the door. If the hangar door needs to
be raised more distance than a garage door does, then more work will be
required for the hangar door, all else being equal.

Of course, if the hangar door is carefully counter-balanced and is on
frictionless mounts, then practically no force is required to move it, and
practically no work is required over the entire opening process.

But assuming that past the gear that reduces the force required on the chain
is a door that is similar in nature to a garage door with respect to the end
resultant force required to move it, you don't get something for nothing.
In order to "extend" the range of the garage door opener enough to match the
total range of the hangar door, you'll have to reduce the leverage of the
garage door so much that the force becomes an issue.

Pete

[Paul Sengupta]

"Peter R." > wrote in message
...
> Jay Honeck wrote:
>
> > Of course, you'd put my kids out of business. (We pay them 25 cents for
> > each opening...)
>
> 25 cents? Wow, that cheap labor. :)

Assuming 1 minute to open the door, that's 60 * 0.25 = $15 an hour.

Paul

[John Clonts]

"Morgans" > wrote in message ...
[snip]
> I have my show sawdust system run by an old opener. The only parts I had to
> buy were two new limit switches, and a bit of wire. The two new switches

Hello Jim,

What in the world is a "show sawdust system"????

Thanks,
John Clonts
Temple, Texas

[Morgans]

"John Clonts" > wrote in message
...
> Hello Jim,
>
> What in the world is a "show sawdust system"????
>
> Thanks,
> John Clonts
> Temple, Texas
>
>

<Chuckle>

That is the same as a "shop" sawdust system, but with fat thumbs, and late
at night.

In the event that you are not up with what I do, I teach carpentry in grades
10, 11 and 12. We have a pretty big cyclone, shared by two shops. It is
loud to talk over, so I wanted to turn it off and on at will, from anywhere
in the shop, thus the Rube Goldberg engineering. My students thought I WAS
CRAZY, until they saw it work. <g>
--
Jim in NC