Is there some trick to tensioning the balance spring on a second hand
door?

There are no obvious holes where a locking pin could have been removed
and trying to do the job in situ is way beyond my strength.

Unlike a domestic window blind, the shaft has a square section at both
ends so you can't just lift one end and wind on some tension. The slats
weigh about 75kg so lifting without mechanical aid becomes progressively
harder as slats are wound on!

Help!

regards
--
Tim Lamb

"Tim Lamb" wrote in message
...
Is there some trick to tensioning the balance spring on a second hand
door?

There are no obvious holes where a locking pin could have been removed
and trying to do the job in situ is way beyond my strength.

Unlike a domestic window blind, the shaft has a square section at both
ends so you can't just lift one end and wind on some tension. The
slats weigh about 75kg so lifting without mechanical aid becomes
progressively harder as slats are wound on!

I was reduced to using a block and tackle to lift the bottom of an open
roller door to form a U shape, until it was high enough for a rope over
the main part of the roll to take over and put a complete extra turn of
tension on. Repeat as required. Not fun, but perhaps safer than risking
anything spinning round.


--
Kevin Poole
**Use current month and year to reply (e.g. )***

In message , Autolycus
writes

"Tim Lamb" wrote in message
...
Is there some trick to tensioning the balance spring on a second hand
door?

There are no obvious holes where a locking pin could have been
removed and trying to do the job in situ is way beyond my strength.

Unlike a domestic window blind, the shaft has a square section at
both ends so you can't just lift one end and wind on some tension. The
slats weigh about 75kg so lifting without mechanical aid becomes
progressively harder as slats are wound on!

I was reduced to using a block and tackle to lift the bottom of an open
roller door to form a U shape, until it was high enough for a rope over
the main part of the roll to take over and put a complete extra turn of
tension on. Repeat as required. Not fun, but perhaps safer than
risking anything spinning round.

Oh!

Fortunately I have access to a masted fork lift.

Presumably your method involved fitting the side guides later? I had
vaguely assumed that it would be possible to insert the tightly rolled
door into the header brackets, wind on a few turns of tension and then
engage the spring axle into the support cups.

However, the access slots in the header brackets appear too narrow to
accept a fully wound door. Fitting one of the brackets later does not
seem very do-able as the frame is set partly inside the door opening.

Grrr.... Roller door fitters must be very strong people.

regards



--
Tim Lamb