PAF Bobbin dementions

[salvarsan]

Here are the dimensions of the PAF bobbins from StewMac.
Sling shit at the imagined methodology as you see fit.

The Stew Mac 50mm PAF screw and slug bobbins were nearly identical to .001".

2.250" core length
0.250" core height (i.e., between the flats)
0.260" core width
0.378" height, external
0.699" flange width

This bobbin size has been added to the list in the Coil Estimator at
http://www.salvarsan.org/pickups/Coil_Estimator.html

-drh

[David Schwab]

What are the meaning of the new choices in the Coil Fill Model pulldown?

[SkinnyWire]

Here are the dimensions of the PAF bobbins from StewMac.
Sling shit at the imagined methodology as you see fit.

The Stew Mac 50mm PAF screw and slug bobbins were nearly identical to .001".

2.250" core length
0.250" core height (i.e., between the flats)
0.260" core width
0.378" height, external
0.699" flange width

This bobbin size has been added to the list in the Coil Estimator at
http://www.salvarsan.org/pickups/Coil_Estimator.html

-drh

My only question has to do with the spacing. It's been awhile since I've bought any parts from StewMac. Do they have 50mm bobbins now, or are they still 49.2-ish?

The rest match well what I've measured.

[salvarsan]

What are the meaning of the new choices in the Coil Fill Model pulldown?

Different names, same percent values for the fill.

• 100%,
• 90.7% (hexagonal lay),
• 78.5% (square lay),
• 72% (tight handwind, or generic machine wind),
• 62% (hand scatter wind)

They are somewhat arbitrary and tend to mean, "Fudge factor accounting for
winding tightness and regularity, and which presumes to represent, at the low
limit, a % fill achieved by a slack-fingered hungover winder's random basket weave,
and at the highest limit, perfect lay 1:1 orthocyclic wind pattern compressed by
high winding tension and overly enthusiastic use of tape.

The 62% and 72% fills kept cropping up when I was doing approximations
on Strat and PAF numbers.

-drh

[fjgaston]

Hi
I don't really understand your coil estimator.
How did you choose the turn per layer? is it a comparison with real pickup (real old PAF for the PAFs)????
I wound very tight with plain enamel grade 1 from elektrisola, 50 turn per layer, a stewmac PAF bobbin, 5000 turn. And had 3,56Kohm, that's approximately what I always have when I exactly stop at 5000 turns. Is something wrong in the way I wind.
I can also notice that the coil is really not completely fulfilled. (I heard PAF where completely fulfilled).
That's what I notice, but my pickups doesn't sound bad, but it doesn't sound like an old 59 PAF.

[salvarsan]

My only question has to do with the spacing. It's been awhile since I've bought any parts from StewMac. Do they have 50mm bobbins now, or are they still 49.2-ish?

These are 49.5mm on the center-to-center pole spacing.

For the purpose of coil estimation, the bobbin core dimensions are the
important measurements.

Whose bobbins are you using?
Would you mind posting some measurements?
I understand the nuisance, so "no" is an okay answer.

-drh

[salvarsan]

Hi
I don't really understand your coil estimator.
How did you choose the turn per layer? is it a comparison with real pickup (real old PAF for the PAFs)????

The turns per layer is arbitrary, empirical, and
comes from numbers when the coil ESTIMATOR
agrees with reported winds+resistance.

It is about 2% low when it estimates your PAF winds. That is better
than the 5+% variance when I use the mean-path estimation method.

I wound very tight with plain enamel grade 1 from elektrisola, 50 turn per layer, a stewmac PAF bobbin, 5000 turn. And had 3,56Kohm, that's approximately what I always have when I exactly stop at 5000 turns. Is something wrong in the way I wind.

If there was _anything_ wrong with the way you wind, your customers would tell you.

Thanks for giving exact numbers so that I can refine this pickup estimator.

-drh

[SkinnyWire]

These are 49.5mm on the center-to-center pole spacing.

For the purpose of coil estimation, the bobbin core dimensions are the
important measurements.

Whose bobbins are you using?
Would you mind posting some measurements?
I understand the nuisance, so "no" is an okay answer.

-drh

I mostly use Guitar Jones (WSC) bobbins. Here's what I measure some of those at:

Guitar Jones 50mm White Screw (Poles measure 50mm Cntr-Cntr):
2.226" (56.54mm) Core Length
0.248" (6.30mm) Core Height (i.e., between the flats)
0.256" (6.50mm) Core Width
0.367" (9.33mm)height, external
0.697" (17.69mm) Flange Width

Guitar Jones 50mm Cream Slug (Poles measure 50mm Cntr-Cntr):
2.225" (56.52mm) Core Length
0.248" (6.30mm) Core Height (i.e., between the flats)
0.259" (6.57mm) Core Width
0.368" (9.35mm) Height, External
0.695" (17.65mm) Flange Width

Guitar Jones 53mm Cream Slug (Poles measure 53mm Cntr-Cntr):
2.330" (59.19mm) Core Length - Flat spot on each end of core
0.248" (6.30mm) Core Height (i.e., between the flats)
0.261" (6.63mm) Core Width
0.378" (9.60mm) Height, External
0.693" (17.59mm) Flange Width

I rounded up the 10,000ths (i.e., 0.2475 = 0.248) and just pushed the "in/mm" button on my calipers for the conversions so if things are different a digit here/there ... Also, just single examples and no black.

[RedHouse]

(salvarsan}Here are the dimensions of the PAF bobbins from StewMac.

The Stew Mac 50mm PAF screw and slug bobbins were nearly identical to .001".

2.250" core length
0.250" core height (i.e., between the flats)
0.260" core width
0.378" height, external
0.699" flange width


{SkinnyWire}I mostly use Guitar Jones (WSC) bobbins. Here's what I measure some of those at:

Guitar Jones 50mm White Screw (Poles measure 50mm Cntr-Cntr):
2.226" (56.54mm) Core Length
0.248" (6.30mm) Core Height (i.e., between the flats)
0.256" (6.50mm) Core Width
0.367" (9.33mm)height, external
0.697" (17.69mm) Flange Width

Guitar Jones 50mm Cream Slug (Poles measure 50mm Cntr-Cntr):
2.225" (56.52mm) Core Length
0.248" (6.30mm) Core Height (i.e., between the flats)
0.259" (6.57mm) Core Width
0.368" (9.35mm) Height, External
0.695" (17.65mm) Flange Width

Guitar Jones 53mm Cream Slug (Poles measure 53mm Cntr-Cntr):
2.330" (59.19mm) Core Length - Flat spot on each end of core
0.248" (6.30mm) Core Height (i.e., between the flats)
0.261" (6.63mm) Core Width
0.378" (9.60mm) Height, External
0.693" (17.59mm) Flange Width

I rounded up the 10,000ths (i.e., 0.2475 = 0.248) and just pushed the "in/mm" button on my calipers for the conversions so if things are different a digit here/there ... Also, just single examples and no black.

On my bench right now are a couple Gibson Burstbucker-II bobbins, four Stew-Mac, and four Mojo/WSC bobbins, all are in the 1.94"/49.2mm form factor.

I get these dimensions:

2.218" (56.3mm) core length - Gibson BB-II
2.250" (57.1mm) core length - Stew-Mac
2.203" (55.9mm) core length - Mojo/WSC

0.255" (6.47mm) core height - Gibson BB-II
0.252" (6.4mm) core height - Stew-Mac
0.248" (6.3mm) core height - Mojo/WSC
(i.e., between the flats)

0.247" (6.27mm) core width - Gibson BB-II
0.259" (6.5mm) core width - Stew-Mac
0.257" (6.52mm) core width - Mojo/WSC

0.376" (9.55mm) height, external - Gibson BB-II
0.380" (9.65mm) height, external - Stew-Mac
0.370" (9.4mm) height, external - Mojo/WSC

0.686" (17.4mm) flange width - Gibson BB-II
0.696" (17.6mm) flange width - Stew-Mac
0.689" (17.5mm) flange width - Mojo/WSC

I also used the In/MM button for conversion.

[salvarsan]

Mojo PAF bobbin specs

The dimensions were consistent between screw and slug bobbins
and always similar to within one thickness of single build 46 AWG (.00173").

In other words, if the bobbin dimensions agree to within one wire diameter,
they may be treated as identical for production purposes.

----bobbin type-----length-width-height-flange
PAF 49.2mm Mojo 2.200 0.255 0.247 0.689"
PAF 50.0mm Mojo 2.232 0.255 0.250 0.695"
PAF 53.0mm Mojo 2.317 0.255 0.253 0.691"

The coil estimator bobbin list has been updated at
http://www.salvarsan.org/pickups/Coil_Estimator.html

-drh