First Attempt at Pickup Building: A Dan Armstrong

[SonnyW]

Well, progress... of a sort.

I drilled a little hole in the bottom of the bobbin to feed the start wire through and soldered a larger wire to it.

Wound 5,000 breakless turns.

The start wire broke in the hole when I went to check continuity.

I'm scratching that method.

I want to leave a length of the AWG42 and join it elsewhere. I'm thinking the baseplate, though at this stage its likely to be brass. But if I fill the hole with solder and the two wires, it would still make the connection, right?

At the very least, I could immobilize the bobbin y screwing it to the plate (I need all the idiot-proofing I can get) and hopefully do a better job of joining the coil wire to the leads.

I'm surprised I could get the 5k turns on only my 2nd attempt, and I'm really surprised at how accepting I am of the learning curve and its attendant 'waste' of wire.

Onward. Which includes at least a little backward.

Here's a tip that might prevent that start wire breaking problem if you use the hole in the bobbin. After you solder the larger wire to the 42AWG, tape that down to the inside of the bobbin, then wind about 5 or 6 turns by hand and then start your regular winding. That should take off the stress.

Or you could do like many people do and just leave the 42 coming out from the start and tape it to the back side of the bobbin until you are done winding. Then solder your larger wire to it and tape it down to the outside of the full bobbin, and cover that with tape do the same with the other end.

[whitebison66]

Third and fourth time are the charm, apparently.

I now have two coils of unbroken wire.



Each is 5,000 winds.



The distribution seems okay, at least for my first attempts.Definitely scatterwound, but not an eyesore (I hope).



I found that I could really control the speed with the wire tension, though I kept my hand on the speed control just in case.

Maybe someone can help me with my latest challenge.

The Sustain Treble pickups have a very distinctive appearance,



but there's no way I can reproduce that manually. So I'll just go for the reissue look. Those pickups have 5mm blades:



I would need to either have replacement blades made up, or I was wondering if I could build 'false' blades into the cover:



My question/problem is that the blade material I have is stainless steel and therefore non-magnetic; will the pickup be able to read 'through' the stainless?



Obviously, the rest of the pickup would be attached, but that at least shows the contact between blade polepiece and the false blade.

Then again, I could circumvent the whole nightmare by recreating this apparent one-off pickup:



I have plenty of brown plastic laying around and it machines a lot easier than stainless steel.

EDIT: having checked with another guitar, it seems the stainless steel is essentially 'transparent.'

That means I can move forward with the construction, and that I am that much closer... to this:

[David Schwab]

\that included 3 breaks I tried none too elegantly to solder together.

Here's a trick for easy splices. Take some insulated hook up wire, like the kind you use from the coils to the coax on humbuckers. Strip off about 1/4" and tin it. Now take the end of the broken coil wire, and the end of the fresh magnet wire from the spool, and wrap them both around the tinned wire. Keep the wrapping away from the insulated end of the wire. After you have 10-12 wraps, solder the end of the wire. Hold the iron on long enough to soften the insulation (for PVC wire). Now cut off the tinned end of the wire from the insulated part. Now take your meter and test from that splice to the start end of the pickup. If you get a reading, you are good to go. Now fold a little piece of masking tape over the splice, and lay it down on the coil, and continue to wind over it.

You should use something like one of those "helping hands" to hold the insulated wire, so you don't break the magnet wire.

I still need to check my winding goal; I want the pickup to end up around 9.5k.

Keep in mind that DC resistance doesn't tell you much about a pickup, unless you are comparing it to a similar pickup wound with the same gauge wire. Once you get a feel for winding, start counting the number of turns instead of the resistance. Keep notes about how many turns gives you what result on a particular bobbin/wire gauge.

[David Schwab]

My question/problem is that the blade material I have is stainless steel and therefore non-magnetic; will the pickup be able to read 'through' the stainless?

No. You must use magnetic steel. There are grades of stainless that are magnetic, like the kind they use for knife blades. But the original pickups probably used low carbon steel.

A few observations. You need to have the blades in the middle of the bobbins. If you would on bobbins that have round holes for screw poles, that wont work.

To make it easy, get some of these bobbins and blades:

Mojotone Humbucker Blade Pickup Bobbin Black

Mojotone Blade for Humbucker bobbin

Then you can make a plastic top if you want to make it solid like the original.

Also, I can't tell from the tape on top of the coils, but if you are just leaving the magnet wire sticking out you will find it's easy to break. You should solder your start lead on first, tape it in the bobbin and wind over the tape. Just stick it out the end of the bobbin, or drill a hole.

[whitebison66]

Thank you, David!

I am using those bobbins and blades. I should have used better photos, but my camera is broken at the moment.

I have yet to tape the coils, but intend to do so very soon.

It was going to be a real struggle to have had the new custom pole pieces fabricated, and the experiment with putting the stainless steel fake blade over the pickup on another guitar seemed to work okay, so I am moving forward with building the cover.

It's a challenge, since I have to make the brass baseplate as well as the plastic cover and figure out how to mate them to each other as well as mount the pickup. For that part, I may emulate the original method and use a machine screw through the back.

Then there's the potting too, but that's still a ways away.

But it's as much (or more) fun as it is frustrating, so I am actually quite happy with it.

Heck, I wound two coils today without breaking wire, and that's progress!

[whitebison66]

Should coils pass continuity tests? Mine don't, but each one shows resistance around 4 ohms. I realized I wound one to 5200 and one to 5500 (because I 'remembered' 5200 as 5500), so I get 4.1 and 4.4 respectively. 8.5 works for me.

I'm still trying to work out joining the baseplate to the cover, but at this point I've got two unbroken coils that I get resistance readings from, so I feel ahead of the curve.

David, you mentioned earlier that I could add 'extra' magnets to these bobbins given their design. What impact would that have on the sound or output?

As always, THANK YOU!

[big_teee]

Should coils pass continuity tests? Mine don't, but each one shows resistance around 4 ohms. I realized I wound one to 5200 and one to 5500 (because I 'remembered' 5200 as 5500), so I get 4.1 and 4.4 respectively. 8.5 works for me.

I'm still trying to work out joining the baseplate to the cover, but at this point I've got two unbroken coils that I get resistance readings from, so I feel ahead of the curve.

David, you mentioned earlier that I could add 'extra' magnets to these bobbins given their design. What impact would that have on the sound or output?

As always, THANK YOU!

Is that 4.1 ohms, or 4.1k Ohms.
If in K ohms, that sounds ok.
T

[whitebison66]

Oops, yes, 4.1k!

[whitebison66]

With 5200 on one bobbin and 5500 on the other (operator memory error), I got 4.1k and 4.4k. For a first effort, I can accept 8.5!

[David Schwab]

Should coils pass continuity tests?

No. Continuity looks for a few ohms resistance. You need to set it int he auto range for resistance.

You must be seeing 4,000 ohms, not 4, unless you have a short. Look for the K on the display.

[whitebison66]

Update: Progress made and catastrophic failure avoided

I linked the end wires of each coil, and made the start wires signal and ground.

One of the things I've really had to think through is how to replicate the Dan Armstrong pickup housing. The originals were cast resin, and that's a little too far for me to go. As already noted, I needed to emulate the rails in the top, which I did with 5mm stainless steel that I none too delicately bent to (roughly) a 12" radius.



I've still got to finish and sand it. I found the easiest way to make it was by using multiple pieces, rather than trying to cut the rails into a solid piece. I've tested its 'transparency' with another guitar, and it doesn't seem to muffle or otherwise interfere with the sound, so that's one worry nullified.

I made a casing from brown plastic that closely matches the original Dan Armstrong color.



I fabricated a brass baseplate of sorts. I attached the bobbins to it, using the Armstrong's slightly wider spacing (7/8"):



I need to attach the cover to the baseplate. In order to do that, I decided to emulate the originals' dual banana plugs on the bottom edge:



But in this case, I'm using a pair of machine screws:



to attach the baseplate, into which I drilled corresponding holes and threaded them with one of the screws:



I still need to drill the hole for the pickup wire through the cover, but at least this way you get the idea.



I am using a modified form of the original pickup attachment method, which was a thumbscrew on the back of the guitar by which the pickup was kept in place. I'll do roughly the same thing, though I may use some foam to adjust the pickup height.



I potted the pickup using tea candle wax, and was greatly relieved that the tape didn't come off the coils and that the bobbins didn't melt. I dipped it at 150 degrees, but I was just nervous since I've never done it before.



I discovered, as I have since read here, that resistance readings go up with the temperature. And that they return to normal when the pickup cools off.

I was just glad that the pickup still worked.

[whitebison66]

The guitar is finished, and the pickup works.

More photos and video here:

[David Schwab]

The guitar is finished, and the pickup works.

More photos and video here:

That came out great. I'm not sure if you know it, but you can get the replica pickups here:

Dan Armstrong Pickups | Armstrong Pickups [edit, yes you said that early on]

I made a lucite guitar once. I have the urge to make myself a lucite bass. Not a Dan Armstrong copy though.

[big_teee]

Ronnie Woods played a Dan Armstrong, when he played with Rod Stewart and the "The Faces"

T