8 Aug
2006
8 Aug
'06
4:08 p.m.
Tony Duell wrote:
Can you recomend any places to start looking (usual disclaimers, of
course). I collect names of companies that sell useful stuff for
hacking/restoration.
I just go to one of the local electronic stores. They have
a wall display of assorted belts, each individually packaged
(to justify the price? :< ). Of course, they have no information
as to *applications* so it is wise to know what you are looking
for before walking in.
I was there today. Had I read my mail before driving over
there, I would have noted the name on the "individually
wrapped" packages for you (I will make a note to check
next time I am in that part of town)
The problem with many of these belts is they usually ride in
a groove cut in the circumfrence of the pulleys. It seems
like the depth of that groove is typically half the "diagonal"
thickness of the belt (assuming a square cross section)
So, one more bit of math involved. It's often easiest to bring
an old belt -- even if broken -- since the packages are
transparent and you can just lay the old belt atop the new
belt and compare sizes.
True, but they cannot do 1-off custom. I have a
handful of much-beloved
reel-to-reel audio tape decks and turntables in need of replacement
rubber. Is there anyone in the world tooled up for custom belts and
rollers anymore?
Are you sure your needs are "custom"? Flat/toothed
belts
tend to be hard to find "in variety"... but I have been able
to find almost *any* of the round or "square" (cross sectional)
belts used in most consumer gear. Do you have an
existing belt to use as a template?
Or, barring that, the diameters of the pulleys and
their center-to-center distances (from which
computing belt size is straightforward...)
FWIW, there's a program in the HP67 Mechanical Engineering Pac (which
will also run on the HP41 series with a card reader) that calculates belt
length given the diameters of the pulleys and the coordinates of their
shafts. It assumes the belt goes round the outside of all the pulleys, it
gets the wrong answer if one pulley is outside the belt (which would be
done if that pulley needs to turn the opposite way)[1].