Building and Construction - Electric Garage Door Opener Problem

Author

Electric Garage Door Opener Problem

slock1@gmail.com

2007-03-24, 1:25 pm

I installed a new 3/4 horsepower Craftsman garage door opener. Went
well, no problems. Close position set and open position sets well.
However, when in the open position, and I push the botton to close the
door, the initial motion is extremely bouncy and tourques the arm
upwards before continuing on it's path to close.

The mounting is solid and the open position is proper (i.e it is open
just short of level and not at a backwards slant).

Is my problem the angle of the arm from the wall to the motor unit?
Or...any other ideas?

Thanks Steve-O

Dan Deckert

2007-03-25, 5:25 pm

The following is assumming your door is running on overhead tracks
(sectional door) and not a 1 piece door with or w/o track. As I presume this
is the 3/4hp chain drive, (53990) you will get some initial torque when the
motor starts up due to chain slack.

Check to see if the guides have any rack in them. This can cause some
binding leading to your start-up torquing of the door mechanism. Rack being
the diagonal measurments of the guide frame.

|\ / |<<measure digonally from ends to a given point of the
equal length along the guides
| \ / <------- Diagonal rack
| \ / |
| \ / | This would be a view from the top or bottom of the
tracks
| \/ |
| / \ |
| / \ |
| / \ |
|/ \ | <given point> Can be 10',12', 14' etc. etc. Just a
check to make sure the guide frame is "square" and not a parallelogram
(http://mathworld.wolfram.com/Parallelogram.html) nor a trapezoid (
http://mathworld.wolfram.com/Trapezoid.html

You state;
> The mounting is solid and the open position is proper (i.e it is open just
short of level and not at a backwards slant).

I hope 'just short of level' is somewhere around +/- 3/16" in 8' from track
to track. (IE: Both tracks are @ the same elevation) In reality, the tracks
need not be dead level from the door frame opening to the end of the tracks
by the motor, but it's better if they are. You can also check to see if the
door is binding, when in the up position, by using the manual release. Pull
the release and push the door to the down position, see if you are getting
any initial binding in the full open position. If it's binding in the
uppermost position, it should be fairly noticeable because the door will
hang and then travel quite freely after you've moved it down some distance.
You can also test this theory by lowering the upper limit in the full open
position. Say you reset the upper limit to only open 3/4's of the way. Then
activate the door and see if you are getting the same torquing as when the
door is in a more raised position.

HTH
Dan

<slock1@gmail.com> wrote in message
news:1174755164.298267.298130@e1g2000hsg.googlegroups.com...
> I installed a new 3/4 horsepower Craftsman garage door opener. Went
> well, no problems. Close position set and open position sets well.
> However, when in the open position, and I push the botton to close the
> door, the initial motion is extremely bouncy and tourques the arm
> upwards before continuing on it's path to close.
>
> The mounting is solid and the open position is proper (i.e it is open
> just short of level and not at a backwards slant).
>
> Is my problem the angle of the arm from the wall to the motor unit?
> Or...any other ideas?
>
> Thanks Steve-O
>

Dennis

2007-03-26, 5:25 pm

One other possibility is too much spring to overcome. Test by releasing the
door pull and see how much foce is present to manually close the door.

"Dan Deckert" <deckert@owt.com> wrote in message
news:PYqdnZSMSqpDfpvbnZ2dnUVZ_g6dnZ2d@owt.com...
> The following is assumming your door is running on overhead tracks
> (sectional door) and not a 1 piece door with or w/o track. As I presume
> this
> is the 3/4hp chain drive, (53990) you will get some initial torque when
> the
> motor starts up due to chain slack.
>
> Check to see if the guides have any rack in them. This can cause some
> binding leading to your start-up torquing of the door mechanism. Rack
> being
> the diagonal measurments of the guide frame.
>
> |\ / |<<measure digonally from ends to a given point of the
> equal length along the guides
> | \ / <------- Diagonal rack
> | \ / |
> | \ / | This would be a view from the top or bottom of the
> tracks
> | \/ |
> | / \ |
> | / \ |
> | / \ |
> |/ \ | <given point> Can be 10',12', 14' etc. etc. Just a
> check to make sure the guide frame is "square" and not a parallelogram
> (http://mathworld.wolfram.com/Parallelogram.html) nor a trapezoid (
> http://mathworld.wolfram.com/Trapezoid.html
>
> You state;
> short of level and not at a backwards slant).
>
> I hope 'just short of level' is somewhere around +/- 3/16" in 8' from
> track
> to track. (IE: Both tracks are @ the same elevation) In reality, the
> tracks
> need not be dead level from the door frame opening to the end of the
> tracks
> by the motor, but it's better if they are. You can also check to see if
> the
> door is binding, when in the up position, by using the manual release.
> Pull
> the release and push the door to the down position, see if you are getting
> any initial binding in the full open position. If it's binding in the
> uppermost position, it should be fairly noticeable because the door will
> hang and then travel quite freely after you've moved it down some
> distance.
> You can also test this theory by lowering the upper limit in the full open
> position. Say you reset the upper limit to only open 3/4's of the way.
> Then
> activate the door and see if you are getting the same torquing as when the
> door is in a more raised position.
>
> HTH
> Dan
>
> <slock1@gmail.com> wrote in message
> news:1174755164.298267.298130@e1g2000hsg.googlegroups.com...
>
>

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