FretMaestro How To

Complete FretMaestro Operating Procedure

Understanding True Level
True Level frets are only possible with the FretMaestro system. Traditional leveling methods relying on flat sanding beams, freehand files, and eyeball guesswork cannot achieve this state. True Level means that every single fret is brought to the exact same uniform height parallel to the fretboard, while perfectly matching the fretboard radius.
This establishes perfect symmetry for the guitar’s true intended structure, delivering the ultimate playing experience:
    • The smoothest, fastest, and easiest play possible.
    • Deep bends without any risk of fret-out.
    • The clearest intonation and sustain for days.

This is a level of precision most players have never experienced before because only Maestroed frets achieve True Level. Not even expensive, specialized CNC fret machines can come close. Once you play a Maestroed guitar, you will never go back.
Step 1: Inspect and Seat the Frets
    • Check for lifted frets: Slide a .001" feeler gauge beneath the bottom edge of each fret tang along both sides of the fretboard to identify any gaps.
    • Reseat loose frets: Use a fret hammer or brass caul to gently tap down any identified lifted frets until they seat flush against the wood.
    • Secure the fret: Apply a thin CA glue using a precision needle applicator directly into the slot to permanently bond the fret tang to the slot walls.
    • Clean the surface: Immediately wipe off any excess glue from the fretboard and frets using rubbing alcohol before it cures.

Step 2: Level the Neck
    • Flatten the board: Adjust the truss rod until the fretboard surface is completely flat, verifying the straightness with a notched straightedge.

Step 3: Access Fret Forensics Worksheet
    • Download the asset: Download the proprietary FretForensics Worksheet directly from the official SixStringers website (SixStringers.com).
    • Prepare the document: Print out the worksheet for manual data entry, or open the digital file directly in Photoshop to log your data on screen.

Step 4: Map Fret Geometry
    • Source the diagnostic tool: Use a digital gauge sourced from a third party, which can be found via links on the SixStringers.com 3rd party resource section.
    • Modify or upgrade the gauge: Note that standard third-party gauge brass blocks are fixed at a 16" radius, making them incompatible with other fretboard radii. To adapt a 16" radius block for universal use across all radii, use a file to reduce the height of the two middle feet by 1/16". For the absolute best and most accurate method, purchase the specialized Gauge Radius Set available directly from the SixStringers homepage product listings.
    • Zero the tool properly: Place the digital gauge directly on the wood alongside the nut at the center of the fretboard width. Always zero the gauge at this specific position and nowhere else.
    • Measure fret heights: Use the zeroed digital gauge to measure the precise height profile of every single fret on the instrument. Make sure the headstock is slightly elevated. This allows gravity to settle the gauge perfectly parallel to the fret. If the headstock is not elevated, your readings will be completely random; the gauge must rest parallel to the fret to ensure accuracy.
    • Log three points: Take distinct measurements at the high E, middle, and low E positions for each individual fret.
    • Notate the variance: Record every individual reading directly onto the corresponding coordinate box on the FretForensics Worksheet to map out the exact geometry.
    • Analyze the data: Study the completed worksheet and use a highlighter to mark the shortest fret and the tallest fret. Deduct the shortest fret number from the tallest fret number to calculate exactly how out of level the frets are.
    • Identify the geometric flaws: The worksheet will reveal that traditional fret elevations are wildly random and fail to conform to a true radius across the width of the fretboard. FretMaestro corrects these errors, bringing every fret to the exact same uniform height coordinate in relation to the fretboard while perfectly matching the fretboard radius, and forming the crowns at the same time. This state of True Level cannot be achieved by any other tool, including expensive CNC fret leveling machines.

Step 5: Mark the Shortest Fret and Analyze Wear
    • Apply indicator ink: Run a Sharpie across the crown apex of the shortest fret to serve as a visual indicator of tool engagement.
    • Apply Glide Strip: Cut a strip using the integrated grid on the Glide Strip sheet. Place the glide strip onto the fretboard on both sides of the working fret. Leave a 1/16" gap between the edge of the glide strip and the fret to serve as a debris gutter.
    • Understand shortest fret rationale: Achieving True Level requires establishing a consistent baseline across the entire system. All frets must be uniform with each other, which necessitates leveling all frets to match the shortest fret.
    • Address groove wear: Fret wear and deep grooves are routinely concentrated on the first four frets. Select the single worst grooved fret to serve as your first target for leveling, applying the operational steps outlined below.
    • Evaluate post-repair height: Once the target grooved fret is leveled, measure its height with the digital gauge. Re-measure the originally discovered shortest fret to compare the values and determine which one is now shorter.
    • Execute shortest fret precedence: If the original shortest fret remains shorter, the newly repaired grooved fret requires additional material removal. First, shift focus to the shortest fret and run the filing steps to establish the absolute low baseline for the instrument. The final tool dial setting used on this baseline fret—along with the presence or absence of the office tape modifier—defines the exact master setting that must be applied to all remaining frets on the board, including the grooved frets.
    • Execute grooved fret precedence: If the newly repaired grooved fret measures shorter than the original baseline fret, its current height becomes the new master reference point. Use this specific depth of cut setting, with or without the office tape modifier, as the uniform target coordinate for all other frets across the instrument.

Step 6: Insert the 150 File
    • Select the initial file: Locate the file marked with 150 or the * symbol.
    • Secure the file: Secure this first interchangeable diamond file into the FretMaestro chassis.
    • Lock the position: Use your thumbnail to press the file inward, rotate the dial to your target setting, and jiggle it slightly until it clicks into its locked position.
    • Protect the dials: When holding the file, do not touch the dials. Placing your thumb directly between the dials is mandatory best practice to prevent accidental setting changes.
    • Establish initial contact: Set the adjustment dial to "0" and execute one or two passes over the fret. Check the ink line. If intact, incrementally adjust the dials for depth of cut until the file begins to remove a portion of the ink.
    • Extra Precision Micro-Stepping: Once initial ink removal is observed, minimize material removal by placing one layer of standard office tape (.0015") under each glide strip. Re-ink the fret, maintain the exact same depth of cut dial setting, and execute another one or two passes. Check the ink again. If no ink is removed, strip away the office tape. If ink is removed, proceed with filing the fret at this refined height.
    • Filing to the Bottom-Out Stop: Execute steady passes until the FretMaestro physically bottoms out on the fretboard/glide strips, at which point the tool will mechanically stop cutting. Inspect the fret apex for remaining ink. If ink persists, advance the depth of cut to the next index setting, place the layer of office tape back underneath the glide strips, and continue filing until the chassis bottoms out again.
    • Mechanical Advantage of the Tape: The native FretMaestro design features 12 mechanical depth indexes calibrated in .003" increments. Integrating a single layer of .0015" office tape under the glide strips effectively splits each index step in half, expanding the system to 24 distinct depth options at .0015" micro-interstitial increments. This micro-calibration preserves critical fret material and shortens operating time.

Step 7: Execute Kinematic Passes
    • Slide the tool: Place the FretMaestro centered on the fret and slide it smoothly along its designated geometric paths. Allow the calculated weight of the Maestro chassis to supply the bulk of the downward force. You may judiciously apply light pressure, but never dig in. Take your time to get a feel for the tool and develop a steady rhythm, which is how you will naturally develop speed.

Step 8: Monitor Ink Removal
    • Verify uniform height: Achieving the target height layout is a built-in mechanical feature of the locked-in depth of cut setting.

Step 9: Progress Through the Files
    • Refine and crown: Swap out the initial file for the remaining diamond files included in the kit. Repeat the smooth, sweeping passes to progressively refine, crown, and micro-finish the frets.

Step 10: Polish and Assemble
    • Final buffing: Give the frets a final buff with fine polishing paper to eliminate minor tool marks, clean the board, and restring the instrument.

Step 11: Address a Worn Fretboard
    • Analyze wood wear patterns: Seldom does finger and string wear reach the nut side of the frets, and it never reaches the saddle side.
    • Determine reference boundaries: The FretMaestro requires a clean .1" reference zone on the wood surface of the fretboard to register correctly. If the fingerboard wood wear encroaches closer than .1" to the fret, the Omni version cannot be utilized.
    • Deploy a fixed radius unit: The correct procedural solution for advanced wood wear is to use a fixed-radius FretMaestro model that matches the original radius of the fretboard (for example, a 12"R tool for a 12"R board).
    • Reference the high ground: The fixed-radius FretMaestro arches cleanly over the localized divots, bridging the wear grooves to reference the uncompromised high ground of the virgin, unworn wood. This mechanics-driven bypass ensures the tool forms a perfect fret radius relative to the original, intended factory fretboard geometry.

Step 12: Select the Correct File for the Task

FretMaestro system includes 3 distinct diamond files, each optimized for a specific phase of the engineering process:
    • The 150-Grit Leveling File: This is the primary workhorse, clearly marked with 150 or a * symbol. It handles the bulk material removal required to bring proud frets down to the established baseline height.
    • The 300-Grit Smoothing File: This finishing file is marked with 300 or the corresponding radius number (such as 12). Never use this file for aggressive material leveling. Execute only a few light passes with it to smooth out the tool marks left by the 150 file. While locking in the depth of cut setting is ideal, it is not absolute for these minor touch-up passes.
    • The 240-Grit Crown Narrowing File: This specialized file is marked with a V or a C. It is engineered to leave the top apex of the fret untouched; instead, it files the side shoulders to narrow the profile of the crown. Setting the depth of cut dial is advised so the chassis bottoms out identically across every fret, ensuring every single crown width is perfectly uniform.
    • Control crown dimensions: The exact width of the finalized crown remains a matter of user preference. Apply a wide band of ink across the fret, execute passes with the narrowing file, observe the ink line narrow down visually, and halt the operation when the desired dimension is achieved.
    • The efficiency shaving trick: On frets that demand deep leveling, use the 240-grit narrowing file to shave material from the side shoulders, alternating between it and the 150-grit leveling file. Reducing the overall surface area of the fret profile dramatically accelerates the leveling efficiency of the 150 file.

Step 13: Technical Diamond File Care and Lifespan Rules
    • Apply dry lubrication: As a best practice, spray a dry lubricant directly onto the face of the file before cutting. This is critically important when working with softer nickel frets, as it lowers surface friction and stops the sliced nickel particles from bonding to and clogging the diamond matrix. This rule applies to all precision diamond luthiery files, not just proprietary FretMaestro components.
    • Perform continuous abrasive cleaning: Keep a specialized rubber belt sander eraser on hand while working. Routinely wipe the file face with the eraser to lift away packed fret debris. Strictly avoid gummy or sticky erasers. As the eraser gathers filings, it will begin to blacken and naturally lose its texture. Discard it and switch to a clean, fresh section of eraser as soon as it becomes sticky or saturated.
    • Control cutting forces: Never force the tool to cut. Rely consistently on the calibrated mass of the FretMaestro chassis supplemented only by smooth, judicious guidance pressure. If the abrasive face starts to catch or dig into the fret metal, instantly back off your downward pressure. This protocol must be maintained across all luthier files, whether diamond or serrated steel.
    • Understand failure points by material: Forcing or digging into standard nickel frets results in immediate loading and clogging, rendering the file slick and incapable of cutting. Conversely, forcing the tool against hardened stainless steel frets will physically rip the embedded diamond grit out of its electroplated nickel bedrock, instantly destroying the abrasive matrix. This vulnerability holds true for virtually every premium diamond fret file available on the market.
    • Track expected tooling lifespan: Adhering strictly to these maintenance boundaries ensures your files remain sharp and service-ready for years. Under proper conditions, expect an estimated operational lifespan capable of completing roughly 60 standard 22-fret nickel guitars or 26 hardened 22-fret stainless steel guitars. While careful users can exceed these baselines, this benchmark provides a fair operational outlook for commercial or hobby planning.

Mechanical Realities and Structural Caveats:
True Level frets make true nut slots possible, followed by a true saddle or bridge setup that establishes string action at the lowest possible height if that matches user preference.
Despite persistent industry assertions that neck relief is an essential adjustment to provide clearance for an oval string vibration, geometric analysis reveals this layout is structurally flawed:
    • Relief Negates Setup Interactivity: Introducing intentional neck bow introduces an artificial curve that directly negates the precision of your nut slots and string action.
    • The Function of Relief: In conventional guitar maintenance, neck relief functions primarily as a deliberate disguise to mask the poor workmanship of uneven frets.
    • The Limits of Flat Sanding Beams: Because a traditional flat sanding beam operates on a straight longitudinal path, its geometry is fundamentally incompatible with radius frets.
    • The Impossibility of Manual Eyeballing: No technician, regardless of experience, can manually eyeball thousandths-of-an-inch precision with a traditional crowning file across 22 consecutive frets. It is mechanically impossible to manually form an exact uniform fret radius that mirrors the fretboard radius using traditional methods.

Executing a FretForensics assessment provides the unassailable empirical data. The physical measurements gathered by the gauge expose the random elevation flaws left by conventional sanding beams and guesswork files, giving you a definitive choice to reject sub-standard workmanship. The FretMaestro system mathematically resolves these geometric deviations, securing an absolute True Level foundation once and for all.