MMD > Archives > June 1996 > 1996.06.13 > 02Prev  Next


Re: Folding Bellows
By Craig Brougher

Larry Toto asked about a clarification about sharp creases in bellows 
coverings. 

 Sorry, Larry. Sounded like I didn't know what I wanted to do,
didn't it?Well, What I meant to say was that sharp creases "strain
relieve" that portion of the cloth in which all the bending would
otherwise be concentrated, so crease them-- hard. Forget what you read
about years ago-- I know I did! Just remember the principles-- why you
do what you do. Not necessarily what somebody says you should do. Ask
yourself, "to what degree is this correct, and to what degree is this
wrong? Is there a time when this may not apply?" Look at everything
like it was a diamond, from all diferent angles, and in different
lighting. And keep asking. Don't take anybody's word for it. You'll
discover a lot of new things.

What I had said about NOT creasing was this:

> Now if you leave a peak fold to "travel" back and forth, or you put in
>a flat fold (I never recommend that for anything) which causes the inside peak 
>on the sides to strip the cloth as it moves, either way, you will wear out the
>cloth MORE RAPIDLY with a sharp crease than with no crease at all.

 In other words, if you allow a crease to "travel," back and forth,
then it will wear out the cloth rapidly because the crease can only
strain relieve transversely, not longitudinally.

 Last word is this: Put a hard crease in, AFTER you have decided that
the motion of the bellows cannot change the length of the crease. Then
put on some Cabretta patches at the inside and outside peaks of the
folds. Use hot animal hide glue.

Carig B.



(Message sent Wed, 12 Jun 96 01:34:29 UT , from time zone +0000.)

Key Words in Subject:  Bellows, Folding