Pickup coil making 101

[Bowen]

How to make pickups from scratch

 

You will need:

Magnet wire, 42 or 43 AWG

Magnet, Alnico or ceramic, 2.5" long x 0.5" wide, polarized on the edges

Poles or screws, I use 5mm steel pins

Bobbin material: plastic bobbins, forbon, wood, etc. ... Between .06" and .1" thick

Baseplate material: brass, copper, wood

Scrap aluminum, hardwood or plastic for building jigs

 

Tools needed:

A winder of some sort (people use drill presses, record players, hand drills, etc.

Table saw

Drill press

Drill bits

CA glue

Sandpaper

Soldering stuff

1/4" fabric tape

Calipers that read .001 inch or .01 mm

Square

Double-sided tape

 

 

 

To start out with, decide what kind of pickup you want to make. I'm making humbuckers here.

 

The dimensions that I have to fit everything in is 1.4" by 2.7". For the neck pickup I'm going to use 6000 turns per bobbin, and the bridge pickup will have 8000 turn per bobbin. The string spacing is 2 inches, so the pole piece spacing is .4" apart. The magnets are ceramic, taken from a set of old pickups, and the pole pieces are 5mm x 18mm pins from the local hardware store.

 

Each bobbin that I use is .7" wide, and 2.7" long and .9" thick. There will be a gap of .315" between the top and bottom plate to wind in the wire.

 

First, you need to build several jigs: you will need a drilling jig, a pressing jig, and a two-piece bobbin assembly jig.

 

Build the drilling jig first. You can then use it to build the others. Use a hard material, as this jig will see lots of action. The material needs to be an inch thick or better, three or more inches long, and a couple of inches wide. Note: This jig should be as accurate as you can make it. Almost every other operation depends it.

 

Use a knife and scribe a centerline down the length of your material.

Scribe a perpendicular line .35" from one edge, then five more perpendicular lines spaced .4" apart starting from your first scribed line.

This establishes the pickup pole spacing, so adjust the number as you need to. Using a fine centerpunch, punch a dimple at the intersections of your centerline and perpendicular lines.

 

Using a drill press, and a drill bit the same size as your pole pieces, carefully drill at the centerpunch dimples.

Using multiple light passes on the table saw, cut a dado that is .700" wide, and almost as deep as your bobbin material is thick, centered on your line of holes.

I did this by setting my caliper to .251" (.7 - .197 (5mm) /2) and using the caliper in the first and sixth hole to scribe an arc onto the plastic that I used. I then took light passes starting from the center going to the edge of my scribed arcs, then repeating on the other side of center.

If you are very careful and go slowly, you can produce a .700" wide dado, with the row of holes perfectly centered.

Using the calipers, measure 2.7" from one end, and scribe a line. With CA glue, glue a square of thin wood onto the jig so that the edge of the square is just barely outside the scribed line. This will act as a stop for your bobbin when it is being drilled.

Your drilling jig is almost done, but it needs to be put to work making other tools before it is finished.

 

 

Now you need to make a pressing jig. This will allow you to drive the pole pieces into the bobbins squarely.

Use a piece of hard material with the same dimensions as the drilling jig, and use double-sided tape to attach it to the drilling jig.

Make sure that the two parts are lined up, then squeeze them together to make sure that the tape sticks.

Using the drill press and the same bit that you used on the drilling jig, drill holes in the pressing jig. Use the holes in the drilling jig as guides.

Separate the two parts, then re-drill the holes in the pressing jig with a drill bit that is slightly larger - 1/64" larger is perfect.

This will allow the pole pieces to be removed from the jig after they are driven into the bobbins.

The pressing jig is done.

 

The assembly jig allows you to but the bottom part of the bobbin onto the pole pieces and ensure that they are parallel, square, and the correct distance apart.

On the table saw, cut a piece of wood that is three or more inches long, and at least an inch wide.

The thickness should be the same your desired distance between the two bobbins.

Use double-sided tape to attach the wood to the pressing jig, making sure that it is centered over the six holes.

Use the drill bit that you used to enlarge the holes on the pressing jig, and drill six holes through the pressing jig holes, and the wood for the assembly jig.

Unstick the parts, then draw a line on the assembly jig that is centered on all six holes.

With a saw, cut the assembly jig down the line that you just drew. It is done, and should look something like this:

[Bowen]

Now you will need to make some pickup bobbins.

On the table saw set the ripping width to .700"(or whatever your bobbin width is). Make sure this is as accurate as possible.

Rip strips of your bobbin material (.06" to .1" thick material, such as ply from the hobby shop, forbon, pickguard material, etc.)to width, then cut them to length, 2.7" or whatever length you would like. The length cut is not as critical as the width, but get it as close as you can to 2.7".

 

Now you should have four rectangles of bobbin material for each humbucker, or two rectangles for each single coil. Slide one into the drilling jig.

 

 

Using the bit that you drilled the drilling jig with, drill 6 holes into the bobbin material through the holes of the jig. Remove the drilled part, then drill the rest the same way.

 

Set half of them aside, and round the ends of the other half, until they look like this:

 

Determine which side of the bobbin plates are going to be the wire side for the top and bottom bobbin plates. Round over the edges biasing the round over towards the wire side of the plate. You can see the rounding in this picture of a completed bobbin:

 

Now you assemble the bobbin. Place one top bobbin plate wire side up onto a hard surface. Lightly place a steel pole piece into the two outer holes, then slide the assembly jig over the pins.

Using a light hammer, tap the two pole pieces into the bobbin. This will align everything. Tap the other four pole pieces in.

 

 

Remove the partial bobbin from the drilling jig (gently, don't let the pins get out of square), and put the two halves of the assembly jig on the pins:

 

Flip this over, then drive the bottom bobbin plate (the one with the square ends) onto the bobbin assembly, until the bottom plate contacts the assembly jig:

 

Remove the assembly jig and using a drop of CA glue for each pole, glue the plates to the pole pieces.

 

Now you will need to drill two wire holes into the bottom bobbin plate for the wire to feed through. I usually have the start of the winding closer to the pole piece than the other hole. That way I don't lose track of which end of the wire is start and which end is finish.

 

You should now have an empty bobbin that looks this:

 

Wrap the metal pole pieces with Teflon tape to protect the wire from shorts. (no pic)

[Bowen]

Winding the pickup

Now you need to thread your wire through the small hole in the bottom plate. Tape the start end of the wire to the poles, and mount the bobbin to the winder. (Google "guitar pickup winder" for inspiration on machines that you can build)

I use 3M double sided tape to mount the bobbin to the winder. If you get the bobbin fairly centered, it will stay even at fairly high speeds.

Start winding, with enough tension to keep the windings tidy all the way around the coil, but not so tight that it breaks. You will break the wire occasionally at first, but that will only give you some practice soldering this thin wire together.

 

Try to keep the winding fairly even across the coil:

 

Keep winding until your counter reaches the desired number or you can periodically check the resistance of the coil with an ohmmeter to determine when to stop.

 

Once you are finished winding, clip the wire from the spool, remove the coil from the winder, and run the end of the magnet wire through the second hole in the bottom bobbin plate.

If you wrap the coil with cloth, now is the time to pot it, if you use narrow vinyl tape, then tape the coil after potting.

To wrap the coil, I used 3/8" fabric tape from the fabric store, and wrap a couple of turns around the coil to protect the wire. Secure the end of the fabric with CA.

 

To pot the pickup I use shellac. Tie or wrap some wire or string around the pickup:

 

Use a sauce jar, or some container of shellac that is deep enough to suspend the coil in, then submerge the coil until it stops bubbling. That usually takes 10 minutes for me.

 

Take it out, and let it dry overnight. While that coil is drying, wind another for your humbucker, pot it, and let it dry.

 

Unfortunately, this is where I stopped taking pictures.

To complete the pickup, use epoxy to glue both coils to the magnet, epoxy the magnet to the baseplate, then wire it up using your favorite wiring diagram available on the net. When you solder the magnet wire to the hookup wire, it is easiest to wrap the magnet wire around the stripped end of the hookup wire, and then just tin the hookup wire. (I suggest using a type of magnet wire that has solderable insulation)

Install the pickup, and then impress yourself.

 

Here are the two pickups that I took pictures of when they were being built. The bridge pickup has a ceramic magnet, 16k ohms, and fairly long pole pieces, the neck pickup has a alnico magnet, short poles, and measures 10k ohms. They are not the prettiest pickups, but they sound great. The next set will be made with bloodwood bobbins.

 

[PolyFmorf]

Awesome stuff. I can get pretty ambitious with amps, pedals and guitars, but I'm not sure I would want to tackle pickup making.

[guitarcapo]

Do you wire the coils in your humbuckers in series or in parralel?

[Bowen]

The coils are usually wired in series, but with 4 conductor hookup wire, they can be series/parallel/singlecoil/etc...

[archiemax]

What kind of shellac you using?? And if you shellac, can you do it at room temperature??

[Bowen]

I use a three-lb cut of shellac at room temperature. It dries all the way through in a day.

 

I picked up the shellac at Rockler's.

[FWAxeIbanez]

what would you say is the overall cost of the pup?

[MadSkillzMan]

i want clilps!

[discountpoolsho]

Dear Thank you very much for guiding us. My little brother has learnt too much from your lesson.

[Fred Buzz]

 

Dear Thank you very much for guiding us. My little brother has learnt too much from your lesson.

 

 

Moron .. next post is 'how to convert video', right?