Geo wrote in message
...
On Thu, 26 Feb 2009 11:13:47 -0000, "N_Cook" wrote:
Does anyone know of a source of data for the traverse spacing, turns per
mm
or mil, for the smallest wire gauges of say 45 to 50 SWG or 40 to 45 AWG.
If wire is 0.05 mm thick, say, then the traverse should lay down at
something marginally wider than that. I appreciate it is dependent on
drawing die imperfections/ enamel thickness/ chaffing etc but at least a
starting value and then suck it and see with a trial run or 2 with the
actual wire. Or a formula for the general case.
I am not sure if an allowance was made?
Looking at the table for travers on the Avo Douglas machine on page 21 of
this
pdf:-
http://www.g1jbg.co.uk/pdf/avowave.pdf
Taking, for example, a 10 thou traverse, the table gives gears of 30,40
and
48,36 which fit precisely into the formula at the bottom of the table for
10
thou wire diameter. Similarly for 20 thou wire diameter.
--
Geo
Useful info there
You must have some excess traverse, for all the previous mentioned reasons
plus back tension variability , non linearity of traverse and dirt, as the
winding will eventually upset and overwind otherwise, just a matter of
gauging how much.
Following on from a previous discussion here on back tension etc, this is
now what I use on my ETA machine, mechanics much like the Douglas
For very fine wire I use a small PTFE
thru chassis terminal as final delivery point, passin wire thru the
where the pin was. ptfe squashed and
then mounted on adjustable metalwork
for the best angle/ work closeness. With as straight as run as possible
between
mandrel , PTFE and supply spool. To give some slack in the wire,
to allow for snatching/ uneven slip-clutch, by allowing the supply wire to
stretch ,
I mount the supply spool about 10 or 12 feet away with
slip clutch and adjustable weight and then a felt clutch
about 2 foot from the spool, far enough for up and down
motion along the spool. Felt clutch made from a strip of
felt wrapped a few turns around the wire and then held
in the clothes line notch of a sprung clothes peg , fixed
to a support.
Where I used to work and a had use of a Douglas the most accomplished, radio
man, had created a 3 way plot for this info. Gauge v back tension v traverse
and some allowance for diameter of former.
--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/