Gold Foil Bobbins

[jrdamien]

Any suggestions on how to fabricate this esoteric little beast?



I can't imagine they're being made and, if they are, I don't have any hope of finding who makes them.

It's such a delicate plastic bobbin and I am kind of stumped.

[copperheadroads]

Card stock & superglue

[jrdamien]

Card stock & superglue

How will this not flare? Even if treated with something to help harden it?

[Lollar Jason]

original bobbins were nylon and very thin so they flair really easily and they often come warped even before you wind them so you have to straighten them- you either have to have a tailstock winder or make a caul to squeeze both sides of the bobbin and then you have to really be mindful of tension setting on the coil wire. Unless you spend a bunch of $ on making an injection mould you have to build them up which is possible but not easy- thats how anyone would make prototypes. Its a somewhat tedious pickup to make- every part has to fit exactly in order to assemble correctly. Not the most difficult but certainly harder to make than most pickup typical designs.

[jrdamien]

original bobbins were nylon and very thin so they flair really easily and they often come warped even before you wind them so you have to straighten them- you either have to have a tailstock winder or make a caul to squeeze both sides of the bobbin and then you have to really be mindful of tension setting on the coil wire. Unless you spend a bunch of $ on making an injection mould you have to build them up which is possible but not easy- thats how anyone would make prototypes. Its a somewhat tedious pickup to make- every part has to fit exactly in order to assemble correctly. Not the most difficult but certainly harder to make than most pickup typical designs.

Thanks Jason. I'm actually working on them right now with the tailstock on my winder for the first time in perhaps ever.

I've got 6 different materials to try. I will not be paying for an injection mould for these anytime soon.

[mozz]

My first prototype would be made out of a 2 liter soda bottle plastic.

[jrdamien]

My first prototype would be made out of a 2 liter soda bottle plastic.

This is a great idea.

But whatever I use will have to be available and applicable past prototyping.

[Jim Darr]

Three ideas come to mind. Not sure how practical though. ALL need a winding face plate that covers the bobbin width & length with a matching tailstock plate on a tailstock winder.

1) Make faceplates out of metal so the pressure will remain on the coil when removed from the winder with two machine screws through the face plate which can be installed before the bobbin is wound (machine screws through the plates in the center of the coil, with tapped metal faceplates to accept machine screws). Make the bobbin using card stock or plastic sheets and a plastic or wooden core. Take faceplates/bobbin and wax pot as a complete assembly, separate the faceplates after the unit has cooled using an "acoustic bridge removal knife".

2) Use faceplates as described out of metal as above with a tailstock winder. Use card stock and wooden core to make the bobbin. Use a bondable wire.

3) Use faceplates as described out of metal as above with a tailstock winder. Use card stock and wooden core to make the bobbin. Use tape on each side of the bobbin flanges and fold the tape over on itself after winding while still mounted on the winder.

My two cents. Always practice safety first when winding or coming up with creative solutions to problems.

[jrdamien]

Three ideas come to mind. Not sure how practical though. ALL need a winding face plate that covers the bobbin width & length with a matching tailstock plate on a tailstock winder.

1) Make faceplates out of metal so the pressure will remain on the coil when removed from the winder with two machine screws through the face plate which can be installed before the bobbin is wound (machine screws through the plates in the center of the coil, with tapped metal faceplates to accept machine screws). Make the bobbin using card stock or plastic sheets and a plastic or wooden core. Take faceplates/bobbin and wax pot as a complete assembly, separate the faceplates after the unit has cooled using an "acoustic bridge removal knife".

2) Use faceplates as described out of metal as above with a tailstock winder. Use card stock and wooden core to make the bobbin. Use a bondable wire.

3) Use faceplates as described out of metal as above with a tailstock winder. Use card stock and wooden core to make the bobbin. Use tape on each side of the bobbin flanges and fold the tape over on itself after winding while still mounted on the winder.

My two cents. Always practice safety first when winding or coming up with creative solutions to problems.

All decent ideas.

But I think the only way to do this, having done some prototyping this far, is to integrate the magnet into the bobbin. That's not how these were done originally, but...

So the magnet becomes the core. Once wound the coil may need to be epoxied while still between the winding plates or perhaps just have some wax applied (basted in wax) to keep it from flaring out of control.

[Jim Darr]

Three ideas come to mind. Not sure how practical though. ALL need a winding face plate that covers the bobbin width & length with a matching tailstock plate on a tailstock winder.

1) Make faceplates out of metal so the pressure will remain on the coil when removed from the winder with two machine screws through the face plate which can be installed before the bobbin is wound (machine screws through the plates in the center of the coil, with tapped metal faceplates to accept machine screws). Make the bobbin using card stock or plastic sheets and a plastic or wooden core. Take faceplates/bobbin and wax pot as a complete assembly, separate the faceplates after the unit has cooled using an "acoustic bridge removal knife".

2) Use faceplates as described out of metal as above with a tailstock winder. Use card stock and wooden core to make the bobbin. Use a bondable wire.

3) Use faceplates as described out of metal as above with a tailstock winder. Use card stock and wooden core to make the bobbin. Use tape on each side of the bobbin flanges and fold the tape over on itself after winding while still mounted on the winder.

My two cents. Always practice safety first when winding or coming up with creative solutions to problems.

Upon further thought I would dismiss #1 and #2.

#1 Would be impracticable in removing the faceplates & wound bobbin from the winder as a unit. Also, you would have to clean the wax off the faceplates really thoroughly and completely after each bobbin is wound. Any chunk, piece, or drip of wax remaining would have to be removed from the faceplates completely. Also, the subsequent bobbins wound might be off if the faceplates were mounted is a slightly different position. This option would be tedious, time consuming, and frustrating. I DO not recommend this as a viable option.

#2 Having an extra type of wire, bondable, would be an added expense and create more unnecessary inventory. Plus you would have the get the bonding agent as well. Not recommended.

#3 This, I think, would work, even with the magnet as the core as jrdamien suggested, and prevent flaring.

[jrdamien]

Upon further thought I would dismiss #1 and #2.

#1 Would be impracticable in removing the faceplates & wound bobbin from the winder as a unit. Also, you would have to clean the wax off the faceplates really thoroughly and completely after each bobbin is wound. Any chunk, piece, or drip of wax remaining would have to be removed from the faceplates completely. Also, the subsequent bobbins wound might be off if the faceplates were mounted is a slightly different position. This option would be tedious, time consuming, and frustrating. I DO not recommend this as a viable option.

#2 Having an extra type of wire, bondable, would be an added expense and create more unnecessary inventory. Plus you would have the get the bonding agent as well. Not recommended.

#3 This, I think, would work, even with the magnet as the core as jrdamien suggested, and prevent flaring.

I will try #3 before I go dripping wax everywhere.

[rjb]

On making the bobbin:
How thick is the original plastic?

:wild speculation:
It looks like it would be fairly easy to vacuum-form from nylon or some other thermoplastic.
Your buck would be a piece of wood or mdf of core thickness, with a rounded rectangle cut out in the middle.
(EDIT: No, the buck should be the rounded rectangle - "positive" vs "negative".)
You could probably make one with multiple rectangles, to form several assemblies at once.
Cut your pieces to size, then glue or thermally bond the center to a flat sheet of same size.*
Your bobbin will have a wall that covers one side of the core opening. Would that be a problem?
Insert a piece of wood, plastic, or metal in the core, to reinforce it during winding (this could possibly be part of your winding faceplate).
After winding, stabilize "somehow" (see Jim Darr's suggestions) and remove the core reinforcement.

* Finding the right adhesive or bonding technique might be the hardest part. Here are some suggestions for nylon.
Bonding Nylon | Industrial Adhesives | Polyamide Surface Preparation
:/wild speculation:

-rb

[Alberto]

Laser cutting some 1mm (0,039'') thick fiber flatwork is what I would do. Like a standard strat/tele bobbin with just one bigger magnet.

[rjb]

Good point. You could wind the coil directly around the magnet- and that appears to be the way they were originally made:
Gold Foil Guitar Pickups Japan...Types & Observations | eBay
But I think fiber flatwork would be considerably thicker than the original bobbin flanges.

FWIW, I have a "toaster-like" DeArmond pickup. The bottom "bobbin flange" is the flat, enamel-painted steel baseplate, and the top flange is two sheets of plastic laminated together - thin black plastic that looks like the stuff acoustic guitar pickguards are made of.

-rb

[jrdamien]

Laser cutting some 1mm (0,039'') thick fiber flatwork is what I would do. Like a standard strat/tele bobbin with just one bigger magnet.

This would likely be too thick for the parts to fit together correctly.