CityCaster-001

A 2023 build!

Contents:

A first body model/shape

Real Size!

... And Real Wood!

Working on the/a fretboard...

New Neck! (same 200y old blond walnut wood)

Installation of the dot inlays

Guitar Body (ies)!

Fretting

My finished guitar

I just love the Telecaster-like shape for guitars (not the only shape I like though) and after my shop was ready with a CNC, and with the experience of having already built a Telecaster pretty much using hand tools under the supervision of Richard Baudry (near Lille), it was time for me to embark on my own journey, making more guitars, for my own use and for the pleasure of making them.

I'm using Vectric Aspire, a software that provides both good (a set of 3D CAD and modeling SW tools (but may be not the most complete) and the capacity to simulate and create tool paths for pretty much any CNC. This SW came with my CNC.

A first body model/shape

I've now moved to Aspire for modeling my first body shape. Starting from a telecaster pdf sheet that I imported to my work, I extracted a few of the elements I need. The body contour, neck pocket dimensions, as well as the two pickups positions and shapes. I worked the body shape to skew it in X direction, and redraw using Bezier curves for a clean shape. Same for pickups and the neck pocket.

I then went on generating the toolpaths corresponding to the different sections of CNC work, and also created specific drill paths for setting reference pins, so I can work on a 2-face model (front and back) without worrying too much about re-positioning accuracy (CNCs are great for that).

I am very happy of the capabilities of Aspire's two-rails interpolations feature to create smooth, curved surfaces, such as the ones that are typically found on guitar necks. I have been able, rather easily, to create this carved neck to fit with the body above.

At least, simulations are looking great!

Real Size!

Time to test in real size certain elements... I'm not worried about the body (I may be wrong but it somewhat seems simpler to me than the neck, so I started with ... the neck!

I placed a protection support on the CNC and a 100x700x20 blank made of MDF (not going to be used in a real guitar) to test my simulations above.

It went OK... I had one issue whith the CNC stopping right in the middle of the back-shaping of the neck. Had to restart and reposition the X & Y zeros and I slightly messed up with the X zero by a millimeter, so the back shape is not as nice as it could/should be. But I have fixed the issue (I was hitting the max Z due to my shaping approach. This is now fixed).

HeadRecess

On-going job

Head & trussrod

Neck Done!

... And Real Wood!

Now that I have a real-size neck done, I can envision using good wood. I happen to have an old bed structure that is made of walnut. When I say 'old' I mean the bed is probably 80 years old, the wood itself probably much older then... That should do.

I have prepared two blanks for necks. After a cut using my table saw and being planed, the wood is very soft under my fingers. Walnut may not be the best wood for necks but I'm willing to try and see what comes out of this!

The small dents that were in the bed and can be seen will disappear when carving the neck back shape as I'll remove a few millimeters of wood going from 18 (body side) to 16 mm thickness (this is without fretboard). My aim is to get to approximately 22 or 23 mm thick for my guitar neck, at the heel side.

I have now made my first hardwood neck. A few mistakes and issues I could correct with a second pass at the CNC to ensure the tuners fit well, and the truss rod fits perfectly in its pocket. It took me about 2h30 to make the neck. I had no issues with the two-sided aspect of the CNC work, and the result is overall pretty good.

A neck base I can use on a guitar at some point. I have now corrected the few errors I found while making my first neck, and adjusted the modeling parts of the neck design so it doesn't appear too weak (it is not in fact, but it *is* thin). A few pictures below:

Neck shape, before contour cut

Neck Top

Neck, sanded to grain 100

Working on the/a fretboard...

I have these boxwood trees that were cut from my place about three years ago after being killed by bugs/butterflies that ate all the leaves, leaving the poor trees with nothing to live from. I looked at the wood and this is so soft after being cut and sanded that I decided to try making a fretboard with it.
Boxwood if a very fine grain, very hard wood, with small color variations from pale to gray. I managed to cut several pieces with 8mm thickness (after planning), 600mm long by 60mm wide (2x30mm, glued together, see left).

So I went on using Aspire to create a fretboard for my next to carve neck. This will be a 628mm scale length (Gibson-like) neck but used/mounted on a Telecaster-like shaped neck & guitar.

As a result of using a 628mm scale length as opposed to the more standard 648mm one, I get 23 frets on the neck (instead of 21). No problem.

The fretboard has a 16" (410mm) radius curvature, and will be approx 5 to 6mm thick. I use the CNC to carve the surface, as I did to set the fretboard blank to be flat and parallel with the CNC.

I use a 10° carving bit to mark frets, carving just 1.5mm deep grooves for the frets, to later be sawn with a proper fret saw at the correct (1.6mm) depth and width (0.6mm). That same bit is used to carve a skyline of Lyon on the surface of the fretboard, that will be just 0.5mm deep and filled with graphite and cyanoacrylate glue.

The pictures below show the design phase in Aspire.

Actual carving will take place mid-August.

:-(... Well... that didn't go as planned. First I forgot to rotate the model so it would fully fit the CNC bed. No damage but that's a reminder of how careful one needs to be with these machines.

Then, and as my blank was not wide enough for an easy clamping, I broke a bit when it met a screw. Had to stop everything, re-caliber the positioning and Z. All paths seem OK and my fretboard was coming out with a beautiful 16" radius all carved until I went to carve the dot inlays... and obviously, these were not at the right spot.
Still at this time I have no idea as what is/was the cause of the problem. One fretboard blank wasted... I have to make other ones.

So... more later - It's a long learning process.

A week after, and with a blank just barely large enough, I managed to make a new fretboard, complete, with almost no issue. I say almost because there's been a small chip of boxwood flying away while cutting the contour. I'll repair that later. Happy with the result! See the process as a video.

New Neck! (same 200y old blond walnut wood)

... To match with the fretboard above

I went back to Aspire and worked on the "few mistakes and issues" I found in carving my fist neck on CNC. This one came out pretty good I must say!

Third one will be even better [I know that's what we all think], but this second and successful attempt is spot on!

I ensured my 'blank' was perfectly flat and parallel for both sides by using a plane path before making my Z-zero settings, and ensuring 21mm height as I was aiming for.

My blank piece not being a perfect parallelepiped, I scribed (with a CNC path) a .3mm deep, 4mm expanded contour on the blank to ensure of the placement of the overall neck and being able to secure it with screws that will not be met by the CNC bits during the job!

Tuner holes have been re-adjusted and now fit perfectly.

Truss Rod channel is now perfectly centered, and the depth is just fine.

The neck shape on the back is better, with a nicer and stronger junction from neck to head.

I didn't mess up with engraving my name/logo. I can always do that later if needed... Might even make a good opportunity to acquire a laser printer :-)

The heel of the neck is no longer a rectangle, but extends following the straight lines on both sides of the neck length (I guess as it should be).

... And after testing, it perfectly fits the fretboard!!!

See a video of the making of this new neck.

Pictures below: One needs clamps (lots of them when glueing a fretboard to its neck.

Installation of the dot inlays

The diameters for the dots are 8mm, I got some aluminum tube with 8mm external diameter and 6mm interior. I placed small plastic (pearl looking) dots in them after cutting small sections of 2mm long. Superglue in the wood holes, hammered in the inlays composed of aluminum+'pearl', and then lots of grinding by hand to get back to the neck surface level, and a sanding pass at 320 grain, using my new 16" radius sanding block.
Next steps: sanding at 400 grain, and then 600... Pfff! And only then the frets can go in.

Dots in place before sanding

After 320 sanding

Using leftover walnut from the neck, I made a fret sorting jig.

I can easily sort and keep (by size) the frets I just cut to size before hammering them into their respective slot.

The holes are 4mm radius, by 18mm deep. The carved numbers are 5mm height, and 1mm deep.

Guitar Body (ies)!

I started (as shown above) with a slightly slanted TeleCaster style body. I really love that shape.

Then with my work on the neck and a Lyon skyline on top of it, I thought maybe it'd be cool to create a series of guitar based on cities, starting with Lyon, of course... So I went on and grabbed a High-resolution scanned city map of Lyon, and began to play with it, tracing the bitmap to get vectors I could carve following the surface of the body (and its arm-rest section). Easier said that done.... It took me two days to find a secure, repeatable process to create a vectorized file to map onto the body shape! But I nailed it :-)

Partial bitmap file (this is close to Perrache)

The result, on the simulator for Lyon

A London version :-)

Back to carving the Lyon version. This series will be called "citycaster". I can do Lyon (first), London, Paris, etc. etc. guitars or bass guitars. So I put together a blank of wood using some leftover nordic pine wood (not a good choice I know) to test the carving process and see what the result can be. If the guitar looks good, I'll make a real version with Alder, Basswood, or Poplar, depending on what I can find. I'll try to stay away from too heavy/too hard woods for telecaster-style bodies.

Carving on CNC is a long process and even more if you have (like in my case) lots and lots of small vectors to carve. Below are some pictures, showing the progress. I also made a small video about it.

Carving pockets and arm rest

Left hand recess

Caring the arm rest area

Body front

carving the main body area

Carving bits (I broke a few...)

Body fully carved after 6h of CNC work

Applied epoxy into the carvings

Control area

The guitar :-)

Neck and ferrude holes ready

Added a "serial number"!

Fretting

I created a fret slotting jig out of a Cumaru to set my fret slots. I believe it's much faster than using the CNC and keeping breaking ø0.6mm bits!
Overall an easy process once you have the right tools and enough precision (thanks to the CNC) to be confident frets are at their correct position all along the neck. Frets were hammered in using a plastic/brass hammer, then on to some protection and the standard beveling and rounding of the fret extremities, some general neck leveling, fret height adjusting, crown leveling, protection and polishing using my Dremel and some polishing compound.

The jig and the saw in use, worked great!

Frets in!

Leveling and polishing frets

Polishing done

Protecting the top for applying some color to the body

Color and satin finish is the choice... For several reasons... -1- I did have some dark blue lying around, -2- the wood is not that great and I had to cover a small error which will disappear under the paint, -3- 'cause I think it will look good with silver HW.

First coat... needs sanding and more coats

Ready for satin finish

Neck top protected and quickly assembled to the body, ready for first satin acrylic coat

After the first coat of acrylic varnish. Still needs full curing and sanding, and 1 or 2 more rounds of varnish+sanding before a final coat

After a small crisis (lost my PC - not my data!) for a yet to understand reason... No audio, then video playback locked, then ... no restart or shutdown (had to HW force it).

Result : I performed a partial reset of the OS, and that didn't do it.

A FULL reset to initial manufacturing state, plus hours of updates (even with a 5Gb/s internet link) plus 1 full day to re-install all my apps and [thank you my trusty weekly backups] my data, I'm back to life (digitally meant of course). BTW the error was in fact due to an AVG (antivirus) update that interfered with the PC audio drivers. AVG is now gone, forever, and replaced with another antivirus program.

My finished guitar

I finished my Citycaster#001 !!! Two more coats of acrylic finishing did a decent job, but in the future I will not use this. I'll go for something harder, that sands better when cured and in the long run will provide better protection to the guitar. I also mounted the strings and had to add a small (1mm or so ) shim under the neck to have the fretboard and strings at the right height compared to the guitar bridge. Not surprised with that as my neck blank thickness was closer to 20.5 mm than the 22mm I aimed for at the begining.

Then some electronics (that was easy, two pickups). I installed a standard neck pickup I had left from a Dean Zelinsky Dellaterra guitar and the bridge pickup is a double blade small humbucker that gives surprisingly good results/sound for its $12 selling price. I mounted it with a coil split too to have that single coil sound when needed. A volume pot, a tone pot, and a 3way splitter, which I may change for a 4way (adding a series pickup position) in the future. The tone pot carries the coil split switch. Really nothing fancy, but the sound (and a good one) is there.

On the pictures below: I'll change the golden knobs for chrome plated ones, just waiting for them to arrive by postal service.