Guitar Router: Buying Guide

Let's face it, when it comes to DIY guitar building, there comes a point where the Dremel, as versatile as it is, is no longer enough. That moment when you look at a cavity for a pickup or a neck pocket and you understand that, to obtain a clean, precise and above all repeatable job, something more is needed. I'm talking about the router, the nightmare and salvation of every hobbyist luthier.

I still remember the first time I had to mill a humbucker slot into a body I'd almost finished. I was in a cold sweat. I'd spent weeks gluing the pieces, shaping the body, sanding. One mistake with the router and I could have ruined everything. That fear, that block, is common to many of us who work in the garage. And rightly so, because the router is a powerful tool, spinning at thousands of revolutions per minute and can cause serious damage, both to the wood and to your fingers. But it's also the tool that opens the doors to a level of precision you could only dream of before. I'm not a professional, I've always said that. I learned to use the guitar router Through trial and error, and a few pieces of wood ending up directly in the fireplace. But precisely because of this, I know what it's like to approach this tool without a fully equipped workshop or years of experience. The goal here is to provide you with a practical guide that will make you feel less alone and more confident when it's time to fire up that beast.

Which type of router should you choose? It's not just a question of power.

The router is just a motor that turns a bit. The real magic is done by the cutter, or router bit. And here, I'll tell you right away, don't skimp on quality. A cheap router bit wears out quickly, burns the wood, makes a dirty cut, and makes you lose time and material.

Essential router bit types for lutherie:

1. Straight Bit: The most common. Used to create cavities, grooves, rebates.
Advise: Get them in different sizes (e.g., 6mm, 10mm, 12mm) with an 8mm or 1/2 inch shank for the main router, and 6mm for the trim router. Router bits with carbide inserts last much longer.n2. Flush Trim Bit: It has a bearing on the bottom, aligned with the cutting diameter. Used to trim a piece following a template.
Advise: Essential. It allows you to perfectly copy the shape of a template onto the piece of wood. There are also ones with an upper bearing. I have a 12mm diameter one with a lower bearing and a 6mm one with an upper bearing for details.n3. Bearing Router Bit: Similar to the flush trim, but with a bearing of a different diameter than the router bit, to create decorative profiles on the edges (e.g., roundover, 45°).
Advise: Useful for chamfering the edges of the body or headstock. A roundover bit (e.g., R3mm or R6mm) is a good starting point.

Router bit materials:

HSS (High Speed Steel): Cheap, but wear out quickly on hardwood. I don't recommend them for precision work.
Carbide (Tungsten Carbide): The best. They last a long time, cut cleanly, and resist heat. They cost more, but pay for themselves in fewer frustrations and wasted wood.
Replaceable inserts: Some professional router bits have carbide inserts that you can replace when they wear out. A larger initial investment, but very economical in the long run. A mistake I made: At first, I bought a set of cheap router bits on Amazon. They lasted me for a couple of cavities, then they cut poorly, burned the wood, and vibrated. I realized that the router bit is like a razor blade: if it's dull, it ruins your skin. Better one good router bit than ten poor ones. Brands like CMT, Freud, or Bosch (the professional series) are a good starting point.

Essential accessories: the true secret to precision

A router, however good, is useless without the right accessories. These are what transform a powerful machine into a precision tool for lutherie.

1. Templates

They are the key to repeatability and precision. Templates are shapes made of MDF, thick plywood, or acrylic that guide the router bit. For what: Pickup cavities, neck pocket, body shape, headstock.
My approach: I bought the first ones, then I learned to make them myself. CAD drawings, 1:1 print, glue onto 10-12mm MDF, cut with a band saw and trim with a trim router and a flush trim bit. It takes patience, but a good template lasts a lifetime and allows you to replicate perfect work.
A trick: If you make a template for a neck pocket, make sure the walls are perfectly perpendicular. Even a small error results in a neck that doesn't fit well.

2. Guide Bushings or Template Guides

They are metal rings that mount on the router base and protrude downwards. They slide along the edge of the template, guiding the router bit. How they work: The outer diameter of the bushing is what follows the template. The inner diameter is where the router bit spins. The difference between the two diameters (offset) determines how much the router bit will cut inside or outside the edge of the template.
Crucial: This offset needs to be calculated. If the bushing has an outer diameter of 20mm and the router bit is 10mm, the offset is 5mm per side. So the cavity will be 10mm larger (or smaller) than the template. It seems trivial, but it drove me crazy at first. You need a complete set of bushings and a precision caliper to measure them.
Advise: Get a set of good quality bushings, compatible with your router. Some routers already have a proprietary bushing system.

3. Clamps

It seems obvious, but securely clamping the workpiece and the template is FUNDAMENTAL. A piece that moves under the router bit is a guaranteed disaster. Type: C-clamps, bar clamps, quick-release clamps.
Where: Secure the body to the bench and attach the template to the body. Use non-slip mats or rubber strips to prevent marking the wood.
An anecdote: Once upon a time, milling a neck pocket, the template has moved slightly. Result? One side of the pocket It was wider than the other. I had to glue a piece of wood and re-mill everything. A waste of time and nerves on edge. Since then, I've fixed everything as if it were supposed to withstand an earthquake.

4. Dust Collection System

The router produces an incredible amount of chips and fine dust. Not only are they bad for cleaning, but they're also bad for your lungs and your ability to see what you're doing. Options: Many routers have a vacuum cleaner connection. A construction vacuum with a good filter is a great investment.
My experience: I started without one, and every time the garage looked like it had snowed. Then I bought a vacuum cleaner, and the difference was enormous. Less cleaning, more visibility, less dust in my lungs. Don't underestimate this aspect.

Guitar Milling Techniques: Steps and Tricks

Now that we have the equipment, let's see how to use it. milling process It requires calm, method and respect for the tool.

1. Preparation of the piece and the jig

Fix the body: Use clamps to secure the body securely to the workbench. Make sure there are no vibrations.
Position the template: Align the template perfectly on the area to be milled. For pickup cavities or the neck pocket, precision is paramount. You can use sturdy double-sided tape (carpet tape, for example) or small nails/screws in the spots that will later be routed out or covered. I prefer double-sided tape to avoid holes, but if the piece is large and the routing is aggressive, a few screws aren't a bad idea.
Verify: Check and recheck the alignment. Measure the distances, use a set square. Every millimeter counts.

2. Choice of cutter and socket

Straight cutter: For cavities.
Copy milling cutter: To trim the edges of the body or copy a template.
Compass: If using a jig, fit the appropriate guide bushing and calculate the offset.

3. Setting the cutting depth

Multiple passes: NEVER attempt to rout the final depth in a single pass, especially on hardwoods or large cavities. This is one of the most common and destructive mistakes. The bit heats up, the wood burns, the router struggles, and the cut becomes messy.
Golden rule: No more than 3-5mm per pass. On hardwoods like maple or ebony, even less.
How to do: Set the first shallow pass (e.g., 3mm). Route. Then lower the cutter another 3mm and route again. Repeat until the desired depth is reached. This is especially true for plunge routers.

4. Milling direction (Climb Cut vs Conventional Cut)

This is a technical detail that makes a big difference. Conventional Cut (or Up-Cut): The router bit rotates clockwise and you move it counterclockwise (or vice versa, depending on how you look at the router). The bit bites into the wood. This is the most common and safest technique, because the router tends to push against the jig, giving you more control.
Climb Cut (or Down-Cut): The cutter rotates clockwise and you move it clockwise. The cutter "climbs" the wood. It is more aggressive and can cause tear-out (chips) and the router tends to “pull away” from your hands.
The trick of the trade (which I learned after chipping a bodysuit): Always take the first steps in conventional cut to rough out.
The last step, the finishing one, do it with a climb cut very light (less than 1mm of material to remove). This drastically reduces the tear-out and leaves a very clean surface. It works especially well on the edges of cavities where the wood is more prone to chipping.
Attention: The climb cut is dangerous. Practice on scraps. Hold the router with both hands and be ready to counteract the thrust.

5. Overheating management

Slow and constant routing: Don't force the router. Let the bit do its job. Move at a constant speed, not too fast to overheat the bit, not too slow to burn the wood.
Clean the bit: If you see burnt wood residue on the bit, clean it. There are specific products, but a little acetone or alcohol can also help.
Take breaks: If you're doing a long routing job, let the router and bit cool down.

Common mistakes and how to avoid them (my very personal collection of disasters)

Every hobby luthier has their graveyard of mistakes. I've done my part, and from those, I've learned more than from any tutorial. Here are the most frequent ones with the guitar router. 1. “I'm going all the way down in one go!”: The classic impatient beginner's mistake. Result: burnt bit, burnt wood, struggling router, crooked cavity.
Solution: Multiple passes, no more than 3-5mm at a time. It seems slow, but it's the only way for a clean job and to not ruin the tool.n2. Jig not properly secured: The jig moves during routing. Result: deformed cavity, ruined edges.
Solution: Sturdy clamps, quality double-sided tape, obsessive checking before turning on the router. If the jig is large, use multiple fastening points.n3. Dull bit: You don't notice it, but the bit no longer cuts like before. Result: burnt wood, smoke, jagged edges, excessive effort.
Solution: Regularly check your bits. If you see that they no longer cut cleanly or that the router is struggling, change them. Don't try to “finish the job” with a dull bit. It's a false economy.n4. Too much pressure or wrong speed: Push too hard or move the router too fast. Result: vibrations, tear-out, danger.
Solution: Let the bit do the work. Move calmly and steadily. The feed rate should be one that allows a clean cut without straining the machine. Many routers have adjustable speed: experiment on scraps to find the right one for the type of wood and bit.n5. I didn't calculate the bushing offset: I route following the jig and the cavity turns out larger or smaller than expected.
Solution: Precisely measure the outer diameter of the bushing and the diameter of the bit. The difference divided by two is the offset per side. If the jig is external to the cavity, the offset is added; if it is internal, it is subtracted. It seems like a puzzle, but once understood, it's mechanical.
Example: 12mm bit, 20mm bushing. Offset = (20-12)/2 = 4mm. If the jig is external (e.g., for a neck pocket), the cavity will be 4mm smaller than the jig per side. If the jig is internal (e.g., for a pickup cavity), the cavity will be 4mm larger than the jig per side. It's not immediate, I know, but it's fundamental to avoid mistakes.

Safety and maintenance: your skin and your tools will thank you

The router is a powerful tool. It's not a toy. Safety comes first. Eye protection: Always safety glasses. Wood chips and shavings fly.
Ear protection: The router is noisy. Noise-canceling headphones are a must, especially for long sessions.
Mask: Fine wood dust is carcinogenic. Use an FFP2 or FFP3 mask.
Hands: Keep your hands away from the rotating bit. Do not wear loose gloves that could get caught.
Unplug from power: Whenever you change a bit, adjust something, or perform maintenance, always unplug the router from the outlet.
Bit maintenance: Clean the bits after each use. Resin and burnt chips stick and reduce cutting effectiveness. Lightly oil the bits to prevent rust.
Check the router: Check that the bearings have no play, and that the locking mechanisms work correctly.

Remember that practice makes perfect. Don't expect the first neck pocket from a master luthier. Practice on wood scraps. It's the only way to get familiar with the machine, understand how the wood reacts, and refine your technique.

If you are thinking of modify a guitar that you already have, perhaps to add a pickup or change a bridge, the router could be your best friend. But only if used wisely and with awareness.

One last thing: when looking for information, don't stop at the first YouTube video. Look for lutherie forums and specialized websites. I've learned a lot from reading advice on Reddit, but also from sites like Stewart-MacDonald's, which is an inexhaustible source of information and tools for lutherie. For example, their guide on router bits is very detailed and gives you a clear idea of what to look for.

Ultimately, the router It's an investment, both in money and in the time it takes to learn how to use it. But it's an investment that will repay you with the satisfaction of creating clean, precise, and, above all, yours*. Don't be afraid to make mistakes, it's part of the process. The important thing is to learn from every mistake and keep trying. If I could do it, you can too.

See also

• Guitar Body Blank: Cutting and Preparation
• The 7 essential tools for building a guitar.