Fret- and Headless Neck-Through Multiscale 6-String (Walnut-burl, Mahogany, Bubinga)

Finally managed to print parts which can hold the magnets properly and are reasonably stable.



A member of the FabLab contacted me today and said that he printed the pickups and the case on his printer. If his parts are better, which I think is very likely, I will use them instead of my feeble attempts

Started rounding over the neck profile. Still need to sand through the grids though.



Half way there ... this form has its appeal as well, but I'm going for more curves.

 

Oh man, it's been quiet around here. Mainly because I've been busy with university and fablab projects.
Let's change that! ... at least the quiet part

The 3D printed parts turned out to be amazing. I'm going to use the case and the PU for the single coil, that means 2x6 Neo magnets on the HB and 9 on the single coil with all of them getting the same amount of winds (~10 000 - 12 000).

The winding has begun ...



Now, the case. Due to how the part was printed the upper face is very rough, the rest looks great though.



In order to hide the front and provide a more integrated look on the bass I decided to glue Wenge veneer to it.
Because PLA is really hard to work with I used PU (Gorilla) glue.



Having this nice flat surface on the front of the bass and keeping in mind that I want have a headstock or truss rod cover to put my mark on I tried to engrave the Wenge.
It turns out the the contrasting parts in the Wenge figure have different density resulting in an uneven image when put under the laser.



I tried filling it with epoxy but that just doesn't provide the contrast I'm looking for.



It turned out that we have a CNC mill at my university and a really nice guy who runs the shop and helped me mill out the engraving with a tiny 0.6mm cutter



It looks much cleaner in reality, it's hard to capture on picture ... very nice, no need to fill it with epoxy.

On different woodworking new: I've been designing a laser cut coffee table and looking for a shop to cut me a matching glass top.

 

Just a short update:

CNC milled the pickup cavity.



The threaded inserts didn't go in straight and one of them just would not come out again.




Glued in a screw and got the insert out. I have to drill out the holes in order to get them in properly and maybe use some epoxy if the holes get too big for the inserts to bite.

Putting in the case it becomes obvious that the cavity isn't deep enough.



I already reworked the gcode so that I can get a reference on the CNC and mill out the 2 missing millimeters.

 

Finished winding the bridge pickup. It measures 9.88k. Now there are only 2 more to go ...

 

Oh man, yesterday was one of those days on which you should never have entered the shop ...

I filed down the threaded inserts and filled two off center holes with epoxy.




But when drilling the holes again in the right location the drill caught on the epoxy and lifted up the bass, drilling through the body.



The fact that the hole is right through the bubinga, mahogany and wenge veneer makes it nigh on impossible to hide with a plug

After some thinking and dealing with the initial frustration I decided to drill through all 4 holes, cut M4 thread in the 3D printed pickup case and mount it from behind. That way no screws will be visible from the front, which I quite like ...




Now I need to redo and engrave the front of the pickup case to get rid of the holes there, but that's just tedious.

Phew, crisis averted

 

Nah, it was just a shocking moment and something good came from it. I already thought about doing a headless string through tuning machine design for my next project and mounting everything from the back of the body would fit right in and leave the front very clean ... it's just an idea, for now.

 

Ah, I took a look at your 32" build. Really clean and elegant design, I love it!

Thanks!

I finished the first HB coil, now only one to go.



Then I did two prototypes for the headpiece. I got it pretty much perfect, just need to shift the truss rod access hole. I will do the final piece once the brass arrives.





Pilot holes:

Code:

%

G21 (using mm)
G40 (manual toolrad comp)

#<feed>             = 400.000000 (Feed definition)
#<z_feed_rate>             = 100.000000 (Feed definition)

#<depth>              = 1 (Pocket depth)
#<z_feed>              = 0.25
#<string_spacing>        = 9
 
#<z-safe>             = 5

#<steps>             = [#<depth> / #<z_feed>]
#<n>                = 0
#<current_depth>    = 0

O101 repeat [6]

    G00 Z[#<z-safe>]
   
    #<current_depth>    = 0
   
    O102 repeat [#<steps>]

        #<current_depth> = [#<current_depth> - #<z_feed>]
       
        G00 X[5.900 + #<string_spacing> * #<n>] Y[5.250] F[#<feed>]

        G01 Z[#<current_depth>] F[#<z_feed_rate>]

        G02 X[5.900 + #<string_spacing> * #<n>] Y[5.250] I[0.950] F[#<feed>]       

    O102 endrepeat   
   
    #<n> = [#<n> + 1]
   
O101 endrepeat

G00 Z[#<z-safe>]
G00 X0 Y0
%

I did the threading by hand because the RPM of the CNC isn't adjustable by the NC.

Code:

%

G21 (using mm)
G40 (manual toolrad comp)

#<feed>             = 400.000000 (Feed definition)
#<z_feed_rate>             = 100.000000 (Feed definition)

#<depth>              = 8.5 (Pocket depth)
#<z_feed>              = 0.25
#<string_spacing>        = 9
 
#<z-safe>             = 5

#<steps>             = [#<depth> / #<z_feed>]
#<n>                = 0
#<current_depth>    = 0

O101 repeat [6]

    G00 Z[#<z-safe>]
   
    #<current_depth>    = 0
   
    O102 repeat [#<steps>]

        #<current_depth> = [#<current_depth> - #<z_feed>]
       
        G00 X[11.140 + #<string_spacing> * #<n>] Y[-13.148] F[#<feed>]
       
        G01 Z[#<current_depth>] F[#<z_feed_rate>]
       
        G01 X[4.094 + #<string_spacing> * #<n>] Y[13.148] F[#<feed>]
        G01 X[5.394 + #<string_spacing> * #<n>] F[#<feed>]
        G01 X[12.440 + #<string_spacing> * #<n>] Y[-13.148] F[#<feed>]

    O102 endrepeat   
   
    #<n> = [#<n> + 1]
   
O101 endrepeat

G00 Z[#<z-safe>]
G00 X0 Y0
%

Then turn the stock and clamp it down at 15° to drill pilot holes for truss rod access and installation screws.

Code:

%

G21 (using mm)
G40 (manual toolrad comp)

#<feed>             = 400.000000 (Feed definition)
#<z_feed_rate>         = 100.000000 (Feed definition)

#<z_feed>              = 0.25
#<string_spacing>    = 9
 
#<z-safe>             = 5


(Hole 1, 4.2mm)

#<current_depth>     = 0
#<depth>             = [9 + 4.121]
#<steps>             = [#<depth> / #<z_feed>]

G00 Z[#<z-safe>]
G00 X[-0.1] Y[15.378 + 0.1] F[#<feed>]

O101 repeat [#<steps>]

    #<current_depth> = [#<current_depth> - #<z_feed>]

    G01 Z[#<current_depth>] F[#<z_feed_rate>]

    G02 X[-0.1] Y[15.378 + 0.1] I[0.1] F[#<feed>]       

O101 endrepeat

(Hole 2, 7mm)

#<current_depth>     = 0
#<depth>             = [9 + 6.452]
#<steps>             = [#<depth> / #<z_feed>]

G00 Z[#<z-safe>]
G00 X[-1.5] Y[26.578 + 1.5] F[#<feed>]

O102 repeat [#<steps>]

    #<current_depth> = [#<current_depth> - #<z_feed>]

    G01 Z[#<current_depth>] F[#<z_feed_rate>]

    G02 X[-1.5] Y[26.578 + 1.5] I[1.5] F[#<feed>]       

O102 endrepeat



(Hole 3, 4.2mm)

#<current_depth>     = 0
#<depth>             = [9 + 8.783]
#<steps>             = [#<depth> / #<z_feed>]

G00 Z[#<z-safe>]
G00 X[-0.1] Y[40.278 + 0.1] F[#<feed>]

O103 repeat [#<steps>]

    #<current_depth> = [#<current_depth> - #<z_feed>]

    G01 Z[#<current_depth>] F[#<z_feed_rate>]

    G02 X[-0.1] Y[40.278 + 0.1] I[0.1] F[#<feed>]       

O103 endrepeat

G00 Z[#<z-safe>]
G00 X0 Y0
%

 

Sorry for the lack of updates. I didn't have the time to work on the bass because I'm involved in a project at my university, but more on that later ...

I started shaping the headpiece and nut:



Still a way to go but I really like how it's turning out and adding to the look of the bass.
Pickups are all wound. Still need to measure them and pot them in wax. A friend talked to a professor at the university and we might be able to use the lab and measure the coils, right down to DC



And now to the stuff that took most of my time, a group project, designing a coffee shop with a bike repair service for the campus and doing all the engineering involved. We opted for modern wood construction techniques

 

Finished shaping the headpiece and put some strings on it.



The witness points were quite hard to set, but I guess that's to be expected on a .130 string.



I had less luck on the other side of the strings ... two M3 threads got stripped during tensioning.
Right now my plan is to disassemble the tuning machines, drill out everything and upgrade to M5.
Only problem is: the space between the two screws on the back of the machines measures only 4.8mm and I would need to drill a 5mm hole through there ...

 

Yeah it is strange, especially because the test worked fine and 4 out of 6 worked. I used WD40 to grease the stud holes. Taking all that in consideration I guess I messed up the threading, after all, this is my first metal working project with no prior experience.
Hmm, I looked at threading specs yesterday and must have read the wrong row ... M4 has a core hole of 3.3 not 2.5 so drilling out the M3 should work out.

 

Thanks guys
I guess that a properly machined M3 tuning machine would work very well and in my test it tuned nicely and tuned with great precision.

I disassembled the whole set, this took quite some time because I needed to cut the threaded rod to remove the string holders.



Then I drilled out all the holes and build a little jig to clamp down the knobs without damaging the knurls.



And everything reassembled ... just waiting for a special thread cutter with an extra small shaft to cut deep stud holes to arrive.