Coil winding back tension versus SWG/AWG table ?
 

Cannot find any on the web.
Easy enough to determine
the ulimate tensile strength of a given length of copper wire
but is the ideal back tensiom while winding say 1/5
of that UTS or some other factor/s ?

N Cook:
1/5 nts is way too high......
For most rf coils, torroids, transformers, etc..... 5% of NTS is adequate...
especially for soft drawn enamel insulated copper.
If you are doing motor armature windings or other rotating coils that will
be subject to centrifugal forces, the 10% number works fine for most of
these applications.
What exactly are you doing?
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

"N Cook" wrote in message
...
Cannot find any on the web.
Easy enough to determine
the ulimate tensile strength of a given length of copper wire
but is the ideal back tensiom while winding say 1/5
of that UTS or some other factor/s ?

"sofie" wrote in message
...
N Cook:
1/5 nts is way too high......
For most rf coils, torroids, transformers, etc..... 5% of NTS is
adequate...
especially for soft drawn enamel insulated copper.
If you are doing motor armature windings or other rotating coils that will
be subject to centrifugal forces, the 10% number works fine for most of
these applications.
What exactly are you doing?
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

"N Cook" wrote in message
...
Cannot find any on the web.
Easy enough to determine
the ulimate tensile strength of a given length of copper wire
but is the ideal back tensiom while winding say 1/5
of that UTS or some other factor/s ?





I was using 40 SWG copper wire which tested as about 400gm / 14 oz
breaking strength. I used 25g/1 oz of back tension and the coil bulk
just about fitted on the bobbin whereas the original had more clearance
ie more packed. I assumed 2 oz back tension was nearer the mark but wanted
to find some published data.