The CNC file I cut this Jazzmaster body from was drawn around a different bridge than the one that showed up on my bench. That is a normal thing to run into and it is fixable, but it is worth understanding before you cut a body rather than after.

Shallow post holes, and the good kind of problem

I am using a KAISH bridge. The holes in the body were too short for the posts and slightly loose side to side. Too short is the good version of this problem, because you can always drill deeper. Too wide or in the wrong place is the version that ruins a body.

The method is boring on purpose. Hold the bit against the post, mark the depth you need, wrap a piece of tape on the bit at that mark, then drill to the tape and stop. Check with calipers before you commit. I went through my bits and 3/8 was too big, 5/16 was too small, and the one in between was right, which is exactly the kind of thing you only find out by measuring rather than guessing.

For the insert that ended up slightly loose, a little CA glue shores it up fine. There was sawdust in the hole and I left it. In this case that is reinforcement, not contamination.

Do not put a drill on pickguard screws

This is the tip I would go back and tell myself. The screws that come with a pre-loaded pickguard are thin and soft. A power driver will strip the head or tear out the pilot hole in a heartbeat, and then you have a screw you can never adjust again. Drive them by hand, work opposite corners like you are torquing a wheel, and let each one find its pilot hole before you lean on it.

Mine were also short on screws in the box, which seems to be standard for the no-name pre-loaded pickguards. Order a few spares with the guard.

Coaxing wires without a special tool

There are purpose-built tools for pushing wires around inside a control cavity and they look almost exactly like a guitar pick. I am an IT guy who plays guitar, so I use a guitar pick. Loosen a couple of pickguard screws, get a bigger pick in there, and steer the wire into the cavity instead of fighting the whole assembly.

The rhythm circuit, and what I would change

Jazzmaster rhythm circuits are a real design decision that made sense for how people played in 1958. My own Fender Jazzmaster Player II does not have one and I do not miss it. You already have a tone control. For how I play, the second one is extra fiddliness in an already fiddly guitar. If I were speccing this from scratch it would go.

What this taught me about CAD

The pickup selector cavity was deeper and wider than it needed to be, same root cause as the bridge posts. The file assumed parts I did not buy. The fix is not better routing, it is standardizing upstream: pick a switch, pick a bridge, model around those specific parts, and stop inheriting somebody else’s assumptions.

That is what pushed me into Fusion 360. It is free for hobbyists and there is a startup license, which matters when the alternative is VCarve at around eight hundred dollars, Windows only, with no free or education tier. I started on Tinkercad and moved up. I am learning Fusion from Martin Harmer, a luthier in the UK I met on a builder forum, whose stuff is at Guitar Assembly.

Two honest notes on parts

The neck is a no-name off Amazon and it came in genuinely good. Straight, decent fretwork out of the box. I still leveled it, but I was expecting worse.

The StewMac polishing pads have great reviews and I am not getting along with them. They load up with material and go slick. Maybe that is me being new. I am going to try fret erasers next.

On bridges, I like the KAISH better than the Fender Japan one I used on another build. People online do not like the nylon bushings. I do. I want the bridge to sit still, not rock. The Fender has adjustable saddles which matters more if you are on a compound radius neck.

Where it ended up

Strung with cheap strings on purpose, because during setup you are going to cut some off and you do not want to be wasting a good set. Dunlop strap buttons, which are more substantial than the stock Fender ones. String tree located by eye, which I am not claiming is best practice, just what I do.

Action is still too high with the bridge decked, so this one needs a neck shim. I am probably going to 3D print a one degree shim rather than fight it. The fretwork though, I am happy with, and that was the part I was worried about.

Perfection is the enemy of progress. The other half of that, which I like better: default to action. There is a big difference between the people who talk about doing and the people who do.

Parts and tools from this session

Links below are Amazon affiliate links. As an Amazon Associate I earn from qualifying purchases, which costs you nothing extra and helps keep the shop running.

• KAISH Jazzmaster style bridge
• Digital calipers, the tool that prevents this whole problem
• Brad point drill bit set
• CA glue
• Pre-loaded Jazzmaster pickguard
• Dunlop strap buttons
• String trees
• Fret erasers
• Neck shims

Follow along

One guy in a small shop on his father-in-law’s property in Lindsborg, Kansas. IT Director by day, maker by obsession. Equal parts problem solver, craftsman, and curious human. If you’re the kind of person who takes things apart to see how they work, or watches people who do, you’re in the right place.

Uncut shop sessions go up on YouTube and I stream on Twitch. Everything is @carverwoodworking. There is merch in the shop, or you can buy me a coffee.