Electric Phin (พิณ)
This is the model for a full sized 3 string electric Phin, a 3 String Thai lute.
Making this instrument required both CNC and 3D printed parts, as well as some hand tools for cleaning things up.
I think you could probably make one using hand tools / a bandsaw / routing table if you wanted to as well!
Model/CAD
The model posted here had been created using freeCAD.
The scale length measures at 22'' (558.8mm) and was matches a Phin I had bought in Thailand.
Fret markers were calculated using the FretFind2D tool
Machining/CAM
Feeds for OPEN BUILDS 1010 LEAD
Material: Poplar wood (technically hardwood, but still pretty soft)
1/4'' fluted downcut (6mm) bit: 20mm/s, 1200mm/min
1/8'' fluted downcut (~3mm) bit: 18mm/s, 1080mm/min
0.5mm Ball nose bit: 15mm/s, 900mm/min
BODY:
Load and Clamp stock (8x3x3'' rectangle board)
Machine out the inlay if desired
change bit and then run pickup/neck/electronics pockets
run the top contour path (this will NOT cut all the way through)
flip the wood stock
pocket the electronics back pocket
finish out the contour from the backside
remove from machine
sand, stain, do what you want!
Finger Board:
This one requires a bit of patience
Machine out the inlays
backfill with epoxy resin and pigment (wait for resin to cure fully before next operation)
plane out the surface until epoxy overfill and stained parts of wood are even (about 0.5-1.5mm)
change bit to 0.5mm ball nose and pocket out the fret markers
take off machine and do the rest of the luthier work on the frets
Neck:
Clamp stock to workplace
Machine out the headstock
Machine out the neck contour
remove stock from machine
finish out the backside radius by hand (working on fixing this in the future)
Electronics
Pickups
The pickup bobbins were 3D printed, then neodyium magnets placed in their press-fit spots on the underside.
#6 iron deck screws were cut to length and placed in the top portion of the bobbin, making good contact with the magnets.
42 AWG Copper wire was then wrapped around the bobbin until a resistance of about 20K was reached using a multimeter.
Hot glue was used to "pot" the pickups.
Wiring:
The pickups were wired to a 500K Potentiometer and 1/4'' output jack using the diagram from:
Seymour Duncan Wiring Diagram
BOM
Materials:
Wood stock (I used Poplar)
3x2'' x8' (back of body, neck, headstock)
3x1/4'' x2' (fingerboard)
1x6'' x1' (Body front)
Slim Fretwire
500K Potentiometer
42AWG Copper Wire
20AWG Copper wire
#6x1' Deck Screws
1/4'' Standard Audio Input Jack
Consumables:
Epoxy Resin
Mica Powder
Keda Wood Dye
Water based Wood Finish
Boiled Linseed Oil/Japan Dryer
Sand Paper
Safety stuff