But what are you actually measuring, is it the distance between each occurrence of a given strand?
Yes... and a bit more than just "yes"
... because the granddaughter is sick, and I'm up anyway.
First, remember that wire gauge and length are the sole factors that determine resistance, and that Kanthal A-1 wire electrically self-insulates with an aluminum oxide surface layer. I mention this because even side by side, and twisted together, we're still dealing with separate wires.
If we take two wires and twist them to a 1mm per ridge rate... that would be a 1mm twist pitch. The tighter the twist, the more wire is required to produce that rate, within a given length, and/or desired resistance.
For the sake of simplicity, I'm going to just make up some rounded values in an example.
Lets say that a pair of wires are 60mm in length, have the 1mm twist pitch rate described above, and produce a "target" (desired) net resistance of 0.4Ω.
if we "loosen" the twist pitch rate to 3mm,
but stayed within that 60mm of length... our resistance would drop because, with fewer twists, we're using less wire - not much, maybe 0.05Ω, so... to obtain the same net resistance of 0.4Ω, we'll actually need to increase the wire length to about 70mm, which might add a wrap or two to our coil.
Were we to go even looser, just a lazy wrap every 5 or 10mm
or more... we'd reach a point where the twist rate has nearly no effect on wire length and resistance... until we reach just two wires, side by side, and the shortest lengths needed to produce our 0.4Ω.
If you refer to the Steam Engine modeling program (see sigline link below), you'll see how, for a given resistance and wire gauge, this works.
In Steam Engine, regardless of the number of wires are used to make a single coil (although Steam Engine limits this to four wires),
it's still considered a single coil... and you would use "single coil" as the set-up.
Because the program already knows, when you click the profile of "round twisted/parallel", that you're using more than one wire to make a coil, it calculates the builds net resistance as it would for regular, multi-strand in parallel
coils.
If you're building
multiple twisted wire
coils... then you click the "set-up" for the number of finished coil assemblies in parallel.
