Alternative flatwork materials for pickups

[Jason Rodgers]

I just got Lollar's pickup book and I'm all excited thinking about building the winder to start rolling my own. Before long I'll have plenty of good questions (and likely a couple stupid ones) for our experts, but here's a pretty simple one: when it comes to sourcing materials, I like going the reused/recycled/scrap route. From my very elementary understanding of bobbin construction, the most basic requirement is that the top flange, core, and bottom flange must be made of some insulative material. Forbon is the "traditional" material, and blingy pickups have a top flange of perloid. Lollar suggests a core (for adjustable screw poles) of Plexi, and most any rigid plastic should do.

So my question is, could pickup bobbin flatwork be made of Formica countertop laminate material? A quick google search reveals that Formica was actually invented as a replacement "for mica" as an electrically insulative material. Does the basic recipe today for countertop laminates still yield an insulative material? What with all the colors and patterns available, it seems like it would be a fun way to make bobbins, and getting small pieces of scrap is easy if you know where to look.

[John Sonksen]

Hey Jason, funny I just started making my own too! I was going to order Lollar's book but haven't gotten around to it yet. I made a winder out of a $20 sewing machine I got on Craigslist and it works fine really, though I'm going to upgrade a few things and have a plan to automate things in sort of a Rube Goldberg way. Anyways, still in the early stages of that so I don't have too much wisdom to share, but I can answer your question about using Formica for this. I would think you can use it, but you will absolutely need to laminate it onto something first. It's just not thick enough and without being applied to anything it's going to be much too brittle, and quite frankly dangerous. Formica and other laminates are basically resin impregnated paper, and it's very prone to cracking, splitting and once it starts it just likes to run. I doubt you could drill out the holes for your screws and slugs in just plain laminate without having it tear on you, let alone cutting the shape. That said, if you could get your hands on some fish paper or circuit board material you could certainly glue it up on there to make the top decorative. I have been toying with the idea of making my own bobbins, but had planned on using pickguard plastic for the tops, or fish paper veneered with wood veneer. If you do go the laminate rout make sure that you don't make your holes too small for the slugs as they are pressed in and would likely propagate a crack if too tight. I would also recommend you use something besides contact cement to glue it up. If you don't let it dry just right the laminate could shift on your substrate while you're tooling it and that would really suck, not to mention it's pretty messy stuff and pretty much requires solvent to clean up, (at least the solvent based stuff does, which is better contact than the water based). So I'd just go with some regular wood glue, epoxy or CA. Keep the pieces small so you don't have to clamp too large an area (formica is usually rolled on after contact is tacky).

Hope that helps! Would be cool to compare notes one of these days!

[Jason Rodgers]

Thanks, John. Being here in the Portland Metro area, we should be comparing more notes, anyways.

When it comes to material properties, I guess I don't have a good handle on how thick/stiff this flatwork needs to be. What if two sheets were laminated together, rough side in, with polyurethane? And I know it's chippy stuff, but on countertops it's glued down and then trimmed flush (or flush and chamfered or radiused) with a "laminate" router for a very clean and smooth edge finish.

The first pickups that I'd like to try would be humbuckers, with screw adjustable pole pieces on both coils, like Bare Knuckle makes. These would have a 1/4" core, all glued together with CA, which would stiffen the whole bobbin and make drilling and tapping easier.

As for the winder, I have the guts of my wife's old sewing machine that broke. I'll follow Lollar's book pretty close, but will leave off the cam-driven wire guide and just do it by hand. Clint Searcy has a great pickup-building youtube, and he does a lot by hand. I'm far from going into production!

[John Sonksen]

I still think it would be too thin and brittle, plus I thought of something else. I've worked with laminate for about twenty years now, and the edge you get from routing the end grain (in terms of the way the rough, back part is oriented) doesn't mill quite as nice as with the grain. It's not major, but it would be exaggerated if it wasn't on a fairly stiff substrate to keep it from chattering. The plastic bobbins have at least 1/16" of material at the top and bottom and I think you'd be shy of that unless you went with standard grade. Now if you were to try and machine a bi-laminated bobbin top, you'd surely need to file it smooth to remove irregularities at the circular edges on either end. If you didn't, you'd be at a high risk of snagging your wire on it and this would surely lead to a break. The wire for pickups is astonishingly thin and the plastic bobbins I've used will give you some leeway in placing your winding as close to the top and bottom as possible. Because the plastic there is smooth and rounded, the wire may make contact with the flat work, but just gets redirected back onto the coil.

If you'd like we can set up a time this week to meet finally and I can show you the process, at least what I know about it up to this point?

[Daryl Kosinski]

Why not clear lexan or plexiglass. Polish the edges and have a see through pickup.

[John Sonksen]

Why not clear lexan or plexiglass. Polish the edges and have a see through pickup.

Don't see why that wouldn't work. You'd see where it's glued together, but it'd still be cool

[Jason Rodgers]

For sure! Lots of options for transparent and opaque colors with plastics. Here's a local place (Portland area) with polycarbonate, polypropylene, polyethylene, acrylic, PVC, and ABS galore!
http://www.tapplastics.com/product/plas ... eets_rolls

With some of that neon transparent plastic, you could even get fancy with LEDs mounted under the pickups to make them glow.

Back to the countertop laminate: I have some bland-looking stuff in the shop that I use to line the inside of side molds. I'll glue up a piece as described above and report.

[John Sonksen]

Well good luck then, the offer to meet up is open btw.

[Jason Rodgers]

Oh, I'm not blowing off your experience or suggestions, John. Sometimes I'm just stubborn and need to try it out for myself. However, do you think the laminate is brittle/chippy in a dangerous way? Like shattering upon contact with a high speed cutter?

[John Sonksen]

Yeah, that's what I was talking about when I mentioned it chattering. I wouldn't be as concerned with the flying pieces as much as when it breaks it is razor sharp. I nearly sliced a fingertip clean off on a piece of broken Formica years ago. I think even if you laminate it onto itself it can still flex enough to break if you don't put enough care into jigging something up so it doesn't bounce when you rout it.

[Peter Wilcox]

I made a plexiglass one for a lap steel a few years ago.

[John Sonksen]

So if you want to go ahead and try it here's how I would do it. Do your glue up first, and like I said use wood glue or something that will actually harden. I'd make your pieces oversized, but not much. The more overhang you try to remove the better chance you'll have of the laminate flexing and shattering. The real danger is in a piece of shrapnel getting caught between some part of your jig, tool and your hand. Trust me, this stuff is like razor blades when it's not cut cleanly. Also, since it will break any time it's moved in two dimensions at once you'll need to clamp it up tight before you attempt to tool it. I don't know how much you've used P-lam, but if you move it the right way it's as easy to rip as a piece of paper. I'm thinking a jig with a top and bottom member that are parallel to each other along the edge you are wanting to tool, with an upper surface that's wide enough to run your router base on in a stable fashion would be the way to go. You'll want it to be tight enough so that not only will it not move up and down in the jig, but also so it can't walk out of the slot where it resides.

After you tool both long edges I would then move onto drilling your holes for the screw heads. I'd probably combine this jig with the prior one for tooling the long edges, and have the holes pre-drilled through the top and bottom of the jig plates. I'd probably use a brad point bit here so that the outer edge is cut cleanly, which should help mitigate a crack beginning which will ruin your piece. With the proximity of the holes on the flatwork you're really going to need to take your time here, cross your t's and dot your i's. When you get through the top lamination, it will likely come off as a disc on the end of your bradpoint bit, at which point you'll need to pull the drill out and clear that piece off before you go for the thru cut.

Then, the last thing I would do is tool the rounded ends of the bobbin flats. I'd probably try and make a jig that would work with a disc sander or belt sander as opposed to routing it because it would be less risky. If you are going to rout it, you'll have to consider that it would either have to be a two step pass per rounded end, in other words routing 1/4 or a circle, stopping to flip it over and then routing the other 1/4 resulting in a hemispheric end, or you would need to create basically a peninsula of support in the shape of the hemisphere that you can use as a guide for your router. This latter option presents a bit of a problem in that the opposing long edge to the side you begin the hemispheric cut will not be supported for a distance of 1/2 the router bearings width away from the end of your hemispheric cut, so that you can complete the pass. I'd personally go for a jig that you could move into the face of a disc sander and then could rotate to remove the excess and get the hemispheres on either end.

So the order of operations that makes sense to me is cut the long edges first. Once you've done that you'll have some nice exact dimensions to locate the screw holes from. Drill these next while you still have more of the laminate at either end. Then tool the half circle ends after the holes are done.

I'm sure it's possible to make these, but personally it's not how I would do it. I think you might be surprised at how much flex is still in the P-lam after you've glued it up. Of course it depends on the laminate you're using, as I said above standard grade is thicker than what is the more common grade today which is usually called postform or postforming. Two layers of standard would probably surpass the 1/16th measurement and be substantially stiffer, but you might not get all of the varieties in that thickness. Also, my shop has a ton of old laminate hanging around, some of it is pretty cool stuff, so if it works I may be able to get you some for a song.

[Jason Rodgers]

Peter, that's stinkin' cool as all get-out! I may be sold on the plexi or acrylic.

John, many of your suggestions have gone through my mind as I imagine this process, so I'm glad I'm on the right track. It may end up being a dead end if it won't be stiff enough for the application. It's fun to think about, though.

[David King]

I've used formica, and it works just fine. It's tough stuff for sure and you'll want to use carbide to mill and drill it over the long run. My main complaint with it is that it likes to curl up with changes in humidity. It has almost no give so you need to size holes for pole magnets more accurately. I cut it on the table saw with a little freud 7-1/4" 40 tooth blade. Absolutely no issues with cuts or shattering during any of the processes and it looks cool too.
It's main benefit besides being free is that it's thin and a lot stiffer than fishpaper/vulcanized fiber at the same thickness so you can fit a lot more wire on a smaller bobbin that still has some integrity.
That said I've moved on to phenolic and am happier with that material as it's uniform throughout the thickness and comes in 1/16" thickness.

[David King]

Come to think of it wood works as well as anything for bobbins and it doesn't take very much wood either. If you need to make multiples of flatwork (what we call the end pieces on bobbins) with all the holes for pole pieces placed identically it's very efficient to drill deep holes in a tall block and then slice that block up on the bandsaw.

[John Sonksen]

I'm just going to have to respectfully disagree David, as far as it being tough stuff. Generally all of laminates strength comes from its substrate, and it's also being used by us as a general term here, which doesn't account for wide variations in strength, thickness, surface finish and manufacturer. I have used standard grade lam which is most commonly used for countertops and indeed in can be pretty tough. That's not to say it can't have problems if the right care and procedure isn't followed in terms of tooling. Thinner grades like vertical grade and post form are even more fragile and susceptible to damage if one isn't careful. We were getting a grade sold as cabinet liner which we were barely able to place on our table saw without it ripping. My assertion that it can shatter comes from personal experience having cut and laminated hundreds if not thousands of sheets worth, which I guess could be seen as an argument from authority, but really what I was trying to convey was an understanding in general terms of the limitations in its strength and where to be careful with machining the stuff. If someone is careful and follows a logical procedure, as I'm sure you did when making your flats, it is possible to use for sure. Would it be my first choice? Definitely not, though I would be more comfortable with first laying it up on another substrate. The key thing to avoid is having the laminate move up or down when an unsupported piece is being tooled. If you aren't careful to hold it down when drilling it can walk right up the bit and that's where it can break. In sawing it, because of its tendency to retain the curl of the rolls it's usually shipped in it can climb right up a saw blade and then be hammered back down if you try and push it forward without implementing downward force on the finished surface. Hold downs in both cases will solve the problem.

In addition different finishes are either quite durable or highly susceptible to scratching, particularly from the highly abrasive dust that's created from tooling. The name of the game is not allowing your dust to get between your tool and the finished surface.

I do have a question for you as far as number of windings with regard to bobbin design, since you obviously have more experience than either of us. Is it possible to make the upright center section taller in order to accommodate thicker flat work, and allow for higher output/more windings, or go down a gauge in wire to say get the same number of 42 gauge as 43 on a standard height bobbin?

It seems like there is enough space to make taller humbuckers than what you get with say precast plastic parts.

[Jason Rodgers]

I figured you'd join this conversation, David. Thank you, this is all good information.

I'm feeling a bit off today, so I'm laying around and doing a lot of searching and reading about pickup construction. Oh my, here I've gone down another rabbit hole.

[David King]

I don't know much about humbuckers of the Gibson variety other than that you are pretty much constrained to the available sources of parts unless you want to invest thousands into making your own molds. If you want taller bobbins then just cut two of them up and glue them back together into one of the dimensions you wish to experiment with. Last I checked, the bobbins were cheap enough. You might then need longer pole screws and slugs so you can see how things are headed.

Fender pickups that use rod magnets are much cheaper to make and are much easier to experiment with since you can get magnets in any dimension imaginable and you really only need flatwork and a suitable tape to wrap the coil in when you're done. There are literally hundreds of covers to choose from if you want to go the route.
Most plastic parts come from a single source in Korea, Daeil chemical. They sell to dozens of distributors around Asia and any of those websites can give you part numbers and dimensions galore. Woosong Chorus (WSC) is a popular place to start.
There seem to be dozens of magnet foundries in China and most of them seem to deal in small alnico rods. Several have online catalogs of just pickup magnets. Your best bet locally for small quantities is Allstarmagnetics in Vancouver, WA. If you know exactly what you want then several of us in the Portland area group together our orders and wait the month it takes to order directly from China.

[Jason Rodgers]

Back up and running. Spent probably 6 hours in the shop yesterday! I'll have some new posts with pictures of the next Mini Lathe and my pickup winder soon.

And back to the laminate: I glued up two small pieces with Gorilla polyurethane with the "grain" at 90 degrees (glad you mentioned this property, John, or I might have missed it). I think the thickness is 3/32". Then, I drew a single coil shape in pencil and cut it out on the bandsaw. The round ends were cleaned up on the disc sander. All cutting and sanding went very smoothly, with no chip out, but a slight bur was left and this was removed with 400 sandpaper. Just to complete the experiment, I drilled some 1/8" holes with a bradpoint bit. Here there was some slight tearout of the outermost later (the colored surface), but I was going a little too fast, and this could have been prevented with more care and attention to a proper backer.

I'll bring this little piece over tomorrow for inspection, John, but I think this method would work. It's very flat, and rather stiff. The cut edge even looks like it could be polished, though not particularly attractive (I wonder if it could be colored black with a Sharpie?). And a little goes a long way: just two 12"x12" laminated sheets would keep me in bobbins for a loooong time.

[John Sonksen]

Back up and running. Spent probably 6 hours in the shop yesterday! I'll have some new posts with pictures of the next Mini Lathe and my pickup winder soon.

And back to the laminate: I glued up two small pieces with Gorilla polyurethane with the "grain" at 90 degrees (glad you mentioned this property, John, or I might have missed it). I think the thickness is 3/32". Then, I drew a single coil shape in pencil and cut it out on the bandsaw. The round ends were cleaned up on the disc sander. All cutting and sanding went very smoothly, with no chip out, but a slight bur was left and this was removed with 400 sandpaper. Just to complete the experiment, I drilled some 1/8" holes with a bradpoint bit. Here there was some slight tearout of the outermost later (the colored surface), but I was going a little too fast, and this could have been prevented with more care and attention to a proper backer.

I'll bring this little piece over tomorrow for inspection, John, but I think this method would work. It's very flat, and rather stiff. The cut edge even looks like it could be polished, though not particularly attractive (I wonder if it could be colored black with a Sharpie?). And a little goes a long way: just two 12"x12" laminated sheets would keep me in bobbins for a loooong time.

Yes, definitely bring it Jason I think the chip out on drilling might be mitigated by using a drill guide on top of the face to hold it down. I think the problem lies in the fact that it's a layered product and as the drill bit plunges through a lot of pressure that was holding the top down is released and on a very small level the layers can bounce up.

I took the liberty of grabbing some laminate strips that I thought you might like and we were going to throw out anyways so you can have those when you leave. I was also wondering if you could bring the Lollar book over, I'd really like to get a look at that before I buy. I also thought I'd mention in case David hadn't, that there is a very good Music Electronics Forum that David himself has done an incredible pickup making FAQ for. I joined a few weeks ago and there seems to be mountains of info to pour over in that place.