Smitty Two wrote in message
news
In article ,
"N_Cook" wrote:

My coil winder is from the 1920s and no manual and when I picked it up
in a
very sorry state, it was minus the tensioning aparatus, so never seen.
This ETA hand winder is something like the Avo Douglas coil winder but
the
manual for that is not very helpful on picture or description, being
part 30
lost in this pic, 50K
http://home.graffiti.net/diverse:gra...t/douglas2.jpg

I made up a workable back tensioner from VCR slip clutch, lightly sprung
pulley carrier etc but it is not very good for evening out the
variation
due to unwinding very light gauge wire from the supply spool giving a
somewhat jerky back tension. It is many years since I was hands-on a
Douglas
and have forgotten what the mechanism is. Anyone know what the Avo
system is
or any other more reliable system. As far as I remember it was a pair of
discs that somehow the wire passed through and the pressure between the
discs was varied for different tension. I also seem to remember that it
too
was not very good at the very lightest gauge wire AWG40 / SWG45 and it
was
better to run through human fingers rather than the discs. At only 1 or
2 oz
back tension it would sometimes grab onto the wire if contaminated or
something and break the wire. But there must be better than human finger
back tensioner.
Is there a 2-stage spool supply process? so the wire is unwound to an
intermediary stage at near enough zero tension that then goes to the
winder
?

I've wound a coil or two; we make guitar pickups. Tensioning requires a
bit of logic and science, but a healthier dose of black magic. We use 42
AWG almost exclusively, and put somewhere between 5000 and 8000 turns on
a given bobbin.

There are happy days when you get 95% yield and annoying days when you
get 10%. There are several components to the dereeling and tensioning
process. I can take some pics of our machine or some copies from the
relevant operator's manual pages in the next day or two if you like,
with further observations.

That would be very helpful.
Can you upload to a site somewhere? if by email, I will have to relay an
email
account/address to you that does not have filters on it.

I've had another google and not found anything useful.

There is nothing wrong with the spool layering , it is just the natural
marginal wedging that occurs with on unwinding, not overlaps , but just
slight variation of a couple of ounces that would not matter if using 8oz
of back tension or more for a thicker gauge, but 2 oz is too critical.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/