CityCaster-003

All right... July 2024... After the successful CityCaster bass (002) build, it is time to start a new guitar. I opted for a '72 telecaster shape, and a 25.5" scale length to keep with standards. Although it was fun to build a totally custom neck for the first CityCaster, it's also something that cannot be easily re-used, as non-standard. At least with a standard scale, there are more options if one has to redo one part or another.

Blanks

My choice for neck blank is a walnut/chestnut/walnut sandwich. I had some old chestnut flooring planks laying around that are fit for such use, and once cut into 3 cm wide pieces, I can use them as perfect quarter-sawn blocks to be glued to walnut. I used my planer/jointer to prepare the pieces of wood, brought them to a final 25mm thickness and assembled them with wood glue. A night after, I had a blank read for a final double side rectification with a 35mm plane bit on the CNC, ensuring I had dead-flat and parallel surfaces. This also brought me to an approximative 22.5mm thickness for my neck.

Time for action!

I stated with the top part of the neck, using a 4mm bit to carve the truss rod (660mm long) channel and ensuring there was a tight fit. The next job was to shate the head surface, first with an 8mm flat bit for the rough pass, followed by a finishing pass with an 8mm ball nose bit. Nice result!

Neck radiusing

The neck is a two-sided shape of course and the back side is carved using two passes. The first one is a rough carve and sets the stage for the finishing pass. Both passes are using ø4mm bits. Unfortunately I had issues on the finishing pass where the bit dieved (so to speak) a little more than 0.5mm too deep in the wood in three arears. I don't know where this came from as the GCode seems just fine, and I had to fill these areas with wood dust and CA glue, creating dark spots on the neck. I don't see a reason for trashing the neck for something that has absolutely no structural impact on the neck, it will just not be 'perfect'.

Neck sanding

As always, once the CNC has done its job, there are some areas that need manual finishing and sanding. I've done this withs rasps and sand paper, and used my laser engraver to mark the neck with my logo and its destination and serial number. At that point the neck is sanded to 180 grit, ready for a fretboard.

Two Necks... Three?

While I was at it, I built another neck from one of the 'all-walnut' blanks I had prepared. I also sliced two oak fretboard blanks and two other fretboard blanks from an iroko piece of wood I had around (from an old chimney mantel!). The neck went on without any issue, flawless!. I did opt for a different rastering strategy when carving the neck shape, using a 45° angle for the finishing pass. Musch slower, but the results are very consistent and very easy to sand, so I may keep this in the future.

The first fretboard I worked on is an iroko one. I started with ensuring the blank was perfectly parallel at 8.5mm thick and glued it to the CNC bed using the double tape method which provides very stable glueing of boards. I used a 8mm round bit to directly create the 16" radius curve for the fretboard and loaded and run the fret slots and 'inlays' pass using a ø 0.6mm bit. That job took about 1/2h, no bit broke :-)
The fretboard was then sanded while still strongly secured to the CNC bed. I used 80, 120, 320 400 and finally 600 grit papers. The result is a very very smooth surface with a natural shine to it. Great looking fretboard.

Attaching [i.e. glueing] the fretboard is an easy task once you set two pins to ensure it will not move as you set all these clamps and press & clean out the glue excess. All this is currently drying. We'll see the final result tomorrow!

Next day :-)

The fretboard is now (glue cured) assembled to the neck. another pass of planing/sanding to align everything perfectly. Side markers drilled. And finally a first coat of sand sealer... for more sanding coming up! 

CityCaster-#004 neck & fretboard

After working on the #003 neck, I wanted to go back to dot inlays made of aluminum & some kind of filler for #004 fretboard. I was also going for an Iroko fretboard as this wood looks gorgeous. I prepared the inlays by cutting some 8mm/6mm  (outside/inside diameters) aluminum tube and filled inlay centers with epoxy mixed with black pigments. A little filing on the bottom face and CA glue will ensure they fit well on the fretboard.

I prepared my fretboard blank, secured it to the CNC bed, and flattened it to 6.5mm (or maybe 7mm) with a 35mm planer bit in multiple 1mm passes. I used blue tape and CA glue to secure the fretboard blank to the CNC bed, works really well..The next step was to create the inlay slots at 8.1mm diameter and 3mm deep. Then I glues (using CA) the inlay dots I had previously prepared and after the glue cured, I files the inlay dots flush to the fretboard surface, using a hand file and a single, 0.1mm CNC pocket pass using the 35mm  planer bit.

I used a 8mm round bit to create the 16" radius on the board, and a 8mm straight cutting bit to trace the contour. After that I removed the excess wood from the CNC bed, and with the fretboard still secured to the CNC, I used a 16" radius sanding beam (built last year) to sand the fretboard with 150, 320, 400 and finally 600 grit. Quite a sweat!

Time for nut and fret slots! I used the center of the fretboard as Z zero reference and created a 4mm wide/3mm deep channel for the nut, and finally cut the fret slots following the 16" radius curve of the fretboard with a 0.6mm diameter bit. That last operation takes about 30 minutes. A quick sanding at 400 and 600 and I have a beautiful fretboard!

Finally the fretboard was glued to neck #004 using lots of clamps. The next day a lot of sanding (to 150 grit) took place on the neck to get a smooth touch. Ready for frets installation!

Frets on #004

I have ordered fret wire, in 2.4mm, copper/Nickel alloy. But I also had a set of pre-cut frets from a Korean manufacturer. So I went on and installed these on neck #004.

The process is the same as in my previous builds. If necessary -not today-, cut the fret wire to length for each fret, hammer them in their respective slot. Once all hammered in place, I cut the fret excess with a special tool and use a fret-rocker to check their height relative to their immediate neighbors, hammer some more if needed, or file the frets if needed. When all 'balanced', use/apply CA glue on the side of the frets to better secure them in the fretboard. That step is somewhat questionable as this may  harden a possible future repair job on the fretboard. I used a 35cm long, 16" radiused beam with 320 grit and them 400 grit to ensure all frets are even in height, and a crown file to recrown the frets that need it. 

The sides of the frets are then files at an angle, and the ends are roughly files towards a round shape. A 150 grit sander on hard foam is used to finalize the shaping of the fret ends. At each step, the neck is cleaned of any fret dust/debris resulting from the filing or sanding actions.

The neck/fretboard is fully protected with tape, only leaving the frets visible and accessible to a polishing pad on a Dremel. This gets the frets to a very shiny and smooth state. The tape is finally removed, and the neck gets another cleanup.

CityCaster#003 side dots revisited

CityCaster#003 neck was not looking good compared to #004. Indeed the side dots were poorly aligned and I had to do something about it before installing frets. I set the neck on the CNC, carefully aligning the Y axis and setting the X and Z zeros. I created a simple pocket I repeated over the neck, in place of the existing dots. I the used boxwood to create small inlays to fit the pockets I just made. The result is just great, with a nice contrast between boxwood and the Iroko fretboard.

Only now is time fore fretting the neck... I received some 2.4mm fret wire this morning (good timing!). Standard procedure as I 'push' with my fret hammer the frets in. Iroko seems to brittle easily so I have to be careful. Pictures below are just as frets are hammered, no leveling, no polishing etc.

And then, leveling, polishing, and prepare for and apply sand sealer... Let dry 24h.

Ready for some body blanks

I went back to Hugo Cuvilliez for quality basswood he has, in order to get two body blanks suitable for telecaster style bodies. We grabbed a nice chunck of timber, cut and split the need pieces of wood and leveled and sanded them to 42mm thickness. The a pass on his huge CNC ensured one side on each half-blank would be perfect to glueing.
Back to my small shop, I glued the pieces together and let them dried in the press for the night. A little cleanup and they are ready for the next stage on my CNC.

Time for some CNC work

I used the CNC to surface both sides of the blank above, then carved the back shapes (belly carve, control cavity), and flipped the body (using the reference pins) to then carve the front shapes (neck and pick-ups cavities, potentiometer holes, selector slot and screw holes, and arm rest shape). It was then time to carve the contour, and the body was 'ready' for a routing with a 8mm 1/4 circle router bit all around the body on both faces, and... for a lot of sanding. a quick pass with 80 grit, the 120, 180, 240 and finally 320... Takes a while...
I also fitted the neck (I chose #004) and reworked the heal shape of the neck to fit/match with the body. I also drilled neck holdin holes, and channels for the pickup wires going from one pickup cavity to the next and to the control cavity.

Engraving the body

A lot of cleaning, and sanding took place to eliminate all CNC tooling marks.

I decided to engrave the city map of Lyon, again, so I have a guitar from Lyon that looks great. CityCaster #001 is nice but the engraving, done with the CNC and filled with epoxy, doesn't stand the comparison with the Bass I built with the London map laser engraved.
I setup the NEJE Max4 for engraving the body and that started a 23h engraving job. I think for next jobs, I'll drive the laser faster with more power. I engraved with 40$ power at 700mm/minute, so obviously I could at least double the speed, increase the power, and even engrave less deep (I get a good 3mm at the time).
I mention this because our power provider has a fail after 20h of engraving, and not only it stopped the job, but the laser engraver did not like this at all... One of the motor drivers burned and I had to order and wait 1 week for a new board. Once re-installed, I could finish the engraving with minimal issues, although there is a tiny engraving glitch that can barely be seen (need a magnifying glass). 

A coast of sand sealer is applied after cleaning the laser engraving with a 240 grit sanding pass. Another 24 of curing to wait before more sanding.

Assembly!!!

After some sanding, and more sanding, and more coats of oil, I'm finally at the point of assembling the different parts together, neck, body, bridge, pickups, etc, and start carving the nut. I must say I'm so far very happy with the look and feel of the instrument.

The two pickups are rather hot double rails humbuckers, one is 12 kOhms, the other 8 kOhms. In the wiring, I provisioned for having both pickup coil-split on the volume knob, and the bridge pickup can be phase reversed with a switch on the tone pot. Pickups can the be alone, or together in parallel or series, using a 4 way switch instead of a Telecaster standard 3 way one. A 47nF capacitor is used for tone, along with a 1nF capacitor for treble bleed on the volume pot. Both pots are 250 kOhms, but I may exchange them for 500 kOhms for a brighter sound (the 47nF will the be changed for a 22nF).

The control cavity is fully grounded with adhesive copper foil.

And Yes,

She plays & sounds great!!! :-)