On Aug 20, 2:29*am, "N_Cook" wrote:
By stacking factor do you mean the ratio of copper volume to the volume
occupied by the copper ? ie the last layers always need squahsing into the
available (calculated) space between former and iron core etc.

Or do you mean 1 is the mathematical theoretical ideal packing of first
layer n, next n-1, next n etc
all precisely registered over the previous layer , within the hollows, that
in itself a fraction of the total volume occupied by the coil , again some
preciese mathematical value for a given wire gauge.
Then 0.7 is the real world ratio of copper for a machine wound coil plus
skilled worker ratio of actual to this ideal.
Then .5 is the likely ratio value for anyone else doing layup of *fine wire
with hand cranked coil winder.

Stacking Factor refers to the overall total ratio.

Knock yourself out laying th wires down carfully versus simply
wrapping them. I would be interested to find out how many more turns
ou got on there by being so neat.

The time when laying wires down carefully really becomes important is
when you're winding a high voltage coil, or a high frequency coil. In
the HV coil you need to make certain the voltage gradient along the
coil is minimal - in other words, keep the voltage between overlapping
turns very low to prevent it from shorting out. In the HF coil you
need to pay attention to the interwinding capacitance, else the self
inductance comes way down on you. The two kind of relate.

This compnay carries wire down below 56 Awg and has some tables and
charts that list min/max diameters for all types of wires. hey had the
most realistic values for realizable coil winding I've found.
http://www.mwswire.com