On 17 Jul 2003 15:59:31 -0700, (dave) wrote:

Do the diy retro fit automatic garage door openers work well ? Am
considering the Motor Lift from Chamberlain from screwfix @ £185.99inc
vat. Any pointers of any difficulties experienced would be appreciated
or any other better value mnufactures to consider ?

I have two of these and they work fine.

The main issue I found was organising a secure mounting above the
doors to take that end of the rail. I have a concrete lintel running
across and above the doors, so found it necessary to create a fixing
in the right spot by using an additional timber secured to the nearest
joist plus a steel bracket. That is installation specific, though.

The information in the picture and with the product as to whether an
extension arm is needed is confusing. I have one of the door types
that they list as needing an arm and I didn't. Therefore I would
suggest buying the lift and checking when you install, then buying the
arm if you need it.

The rest of the installation is uneventful. A bracket fits to the
wall above the door. There is a steel rail which comes in sections
that you bolt together and then onto the motor. There is a carrier
which runs along the rail and is moved back and forth with a tensioned
chain around a sprocket on the motor.

The assembly is then fitted into place and the motor unit attached to
the ceiling or to a joist using steel straps. You may need to do
some organising of fixings here as well, although I didn't. Mains
power to the motor is needed as well of course.

If you have the type of door with latches on the sides operated by
cables or rods, these need to be disabled. The door is held in
place when closed by the arm and the chain. The motor drive is via a
worm gearing arrangement so that short of very heavy heavy forcing of
the door by a gorilla it won't open. Nevertheless, I re-incorporated
the latches using a mechanism specifically for the job:

http://www.amourelle.co.uk/securidor.htm

This makes the locking a bit more substantial - at least as good as it
was.

This company also sells replacement bits for doors, such as springs,
which you may need if yours have become tired.

I also added some additional locking and security features to beef it
up even more.

There are then limit and force adjusters which need to be set up.
The force setting is adjusted so that there is comfortably enough to
open and close the door.

There is a built in safety mechanism whereby if the door closes onto
an object, it is detected (by resistance to travel at the motor) and
the door opens again. However, the force can be quite a bit
(although probably not enough to cause injury) before it detects and
reverses, so if you have small children etc., the manufacturer makes a
photoelectric beam accessory which will detect things in the way and
reverses the door. B&Q stock these as well as other accessories
like remote keypads etc.

After a bit of adjusting over the first few days, both systems have
performed faultlessly.



..andy

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