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When installing the end jack, do you typically have slop sideways? Betfore locking down the jack, i can wriggle the inside end maybe 1/2 to 3/4 of an inch.
I expected the pin to be tight enough to need to use sand paper to fine tune the hole enought to just slide the jack through the end block.


I drilled a test hole in a piece of plywood using a cheap forstner bit and a hand drill. and had the above result.
Thinking the runout on the hand drill maybe excessive, i did the same with my drill press with the same result.

I measure the endpin At 0.45 in. My bit at 0.47 and the hole looks like a tru 1/2 in. (still have to find my calipers to verify but...),
so i have .05 in of slop. Is that excessive?
Will locking it down preven any shifting?
When i locked it down finger tight it did seem to hold, but that's not with the weight of a cord on it...

I don't want to end up with a ring of wear as the pin shifts with use.
Am i obsessing??

Rob

Did you use a forstner bit on the advice given in the installation instructions? When I installed my first K&K, that part of the instructions sounded dubious to me so I asked here and got good advice on better methods.

Check out this thread: http://luthiersforum.com/forum/viewtopic.php?f=10101&t=44971&hilit=forstner

I've followed David Collins' advice (starts about 1/3 of the way down on the first page) with very good results. No slop at all.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Thanks Jay!! I am soooo glad i asked before doing the install. I am at a loss why the K&K instructions are the way they are.

https://www.facebook.com/pg/a2guitars/photos/?tab=album&album_id=113600518747043

The whole world, well most of it installs jacks incorrectly and that is why they come loose. Forget K&K's instructions, they are BS....

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Ann Arbor Guitars

Well, it's good to know that I wasn't overreacting.
Let's see what K & Ks response will be...

Thanks for the link to AAG, Alan. It made me smile because I've been using a 15/32" bit for installing pickups only because I couldn't find the instructions to the very first one I installed. So I measured it and used what I found to be the appropriate bit. That tidbit about the 1/4" rod is brilliant. No more fishing line for me!

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Years ago I did under saddle pickups and used a 1/2" bit for the jack. They kept coming loose and I finally realized the hole needed to be sized properly. The 1/4" rod, or a stick with the end carved down, is for sure the way to go.

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Steve Smith
"Music is what feelings sound like"

I broke down a long time ago and bought the StewMac reamer. After the taper it has a cylindrical 15/32 section, then steps up to 1/2. It was hard to justify on my first pickup install but I've reamed enough holes (and never had a problem) that it has more than paid for itself.

One thing that's important to me is the ability to move a hole with a single flute reamer.
Many binding/purfling designs put the edge of the jack washer very close to one of these lines. This makes it painfully obvious when the hole is just minutely off center. By using the reamer buy hand, (make a removable T handle), you can move it back and forth just a quarter of a turn and move the hole where you need it. Just make sure you have enough room to re-round the hole. This allows you to not only get a perfect new hole, but fix an off center end pin hole while you install a jack instead of just making an earlier mistake bigger. Violin folks use this method to move peg holes around all the time. Even if the end pin was off to begin with, my jack installs won't be sent out with a disclaimer about someones previous mistake so I want mine to be spot on.

David I just installed an Anthem last Friday that I had to move the hole for the same reasons and the SM reamer did it so very well I found myself doing a double take at how well it was centered even though it didn't start out that way. Nice to have great tools that work great every time!

The SM reamer is pricy but mine has likely installed hundreds of pups now and it's still sharp as can be.

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Ann Arbor Guitars

Ended up using a 29/64 drill and the fit was nearly perfect. A little bit of sanding and it slid in nice and snug.
Took a lot of deep breaths before drilling into that side though. That was about as nerve wracking as routing the binding channels.
Well worth it though. Am Very happy with the result and sound.!!

Peace out

I didn't like drilling the hole freehand since straight alignment of the jack is so important for having the jack washer sit flat on the outer surface. I made this contraption/gizmo that allows me to use my hand drill like a horizontal drill press.

Here are the main parts: the drill, a drill guide, and a block with notches for clamps to hold the guide and drill in position.



Drill and guide clamped to the block which is clamped to the bench. The guitar is in a cradle clamped to the bench and aligned with the drill. I drill a pilot hole and follow with the StewMac reamer.



Drilling the final hole with the reamer. The weight of the sand bag neck rest sitting on top of the guitar keeps the body seated in the cradle.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

J what's that thing coming off the end of the drill and wrapped all around it shown in the first pic? I've got the same drill someplace around here from back in the day...

I know it's high pucker factor when you don't drill our the butt wedges very often but there are not a lot of things that can go wrong here either. Be sure to use a sharp bit, I like brad point and if you have your vice attached to your bench you develop references like the markings on an air craft carrier deck that help you align the drill on all axis.

David's point that with this reamer you can walk the hole over a bit is a good one and something that folks who install pups often likely rely on. I sure do.

It's also a good idea to chamfer the finish edge too to help keep the finish in place when installing and removing the jack. An over sized counter sink bit turned backwards by hand is what I use and it only takes a couple of seconds to do.

Using Dave Collins method as shown on our FaceBook page takes several tries to get it locked in as intended and desired which is another good reason to chamfer the finish edge since you are removing the thing each time.

Some additional notes of interest. Many Guilds from certain periods such as the 70's had tail blocks that were too thick to install most pup jack assembles. For these a shop-made counter bore used blind does the trick.

Be sure too to tell your customers that leaving the thing plugged in will eat batteries AND increase the risk of having to pay me to repair the broken head stock when your roadie trips on the cord....

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Ann Arbor Guitars

Hey, it's a vintage, historic, timeless classic power tool that gives me constant access to to a virtually inexhaustible supply of power coming all the way from the Grand Coulee Dam. Now that's power! Hydro power! Except when the power goes out after a wind storm, or when I trip over the cord and yank the plug out of the wall. Oh yea, AND, the cord serves as a chuck key retention device. End of rationale...

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Jay, that's quite the rig.

When I did my testing, first I used a cutoff from the sides and did my hole freehand. As the bit exited the backside, it would grip he wood and rip it from my hands sending it spinning into the void... My anxiety mounted.

Then I glued it down to a piece of scrap 2 x 4 and it passed through the side fine, but then as it hit a grain-line in the 2x4 it would put a death hold on that scrap and sent it AND the drill flying from my hand off into the void... visions of the guitar doing likewise had me trying to come up with alternatives. when I figured out it was binding on the grain in the whatever type of wood that 2x4 was, and I knew I had a buttery smooth piece of mahogany for an end block, I relaxed a bit, promised I'd pay off my old library card bill if it went smoothly and went for the gusto.

I didn't really think about a skewed hole causing the washer not to sit flat. Probably should have. I had done a little research and saw an article about using mirrors with the drill to determine whether you're level, much as you can use the mirrored back on a chisel to help align a cut... but didn't think that this was that critical.

Filing it away for future consideration. Thanks!

Rob, the beauty of Jay's rig is it shifts the risk away from the instrument. The sand bag insures that when his Grand Coulee powered drill encounters resistance, the guitar stays motionless and it is he that spins. At that point all he has to do is remember to release the trigger at the right time to land on his feet.

Oh yea, I forgot to mention that the cord acts as a safety feature. By having the drill rig positioned at full cord length from the outlet, the moment the drill starts to spin the plug gets pulled and the drill powers down before I can even react. Pretty clever, huh.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Genius!!

(whew! I had to wait 2 days to get that word out!)

Thanks for the encouragement to spring for the StewMac reamer. It arrived today and was put to good use. As mentioned, it is easy to adjust the position of the hole as it is gradually enlarged so that it ends up centered with respect to the tail graft and the ID is dead-on perfect.

Good going David. The reamer is really a great tool if you do enough work on guitars to justify it.

Mine has been used hundreds of times now and if it's duller, and it has to be, I haven't noticed it yet. Nice tools are a real pleasure!

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Ann Arbor Guitars