MIMF

Posted: **Thu Sep 03, 2015 3:57 pm**

Awhile ago I've made a very simple stick bass.
After a couple of months of playing I tried hanging it around my neck instead of using a stand and this worked out fine, giving me more room to move around.

Recently I've made a six string version of it.

: Overview stick quintar.JPG (112.98 KiB) Viewed 15593 times

Building it was a pretty straightforward procedure, it's just a tapered piece of plywood, stained with Indian Ink and finished with floor lacquer.
Building time was under 16h / 2 workdays (drying time excluded).

Specs:
Tuned in fifths (Low C (one step above low B string), G, D, A, E, B (tuned as B of a regular guitar))
800 mm (approximate 32") stringlength
300 Ohm Low Z pickup with balanced microphone output
No trussrod

I've recorded a short soundclip

Hans

Posted: **Fri Sep 04, 2015 3:56 pm**

That's very cool, Hans! And the sound clip is nice. You really should give us a little more detail, more photos and tell us a bit about that pickup. Sounds like it's pretty noiseless.

Posted: **Fri Sep 04, 2015 11:16 pm**

Man, you sure do make plywood look good! I do not say this in jest, as I'm impressed with your patience and skill with using plywoods in your prototype builds.

Yes, please give a full-frontal shot of this one, as well as more info on the pickup, as Mark requests.

Posted: **Sat Sep 05, 2015 9:54 am**

Thanks guys for your replies.

A few other reasons why I came to this design are that I'm always drawn to practical and simple (minimalistic?) designs. Further our home is crowded with (lovely!) people, so stacking piles of instruments is not an option. This design gives room for more instruments (I would love to make an 12 string version...) without taking up too much room.
Last but not least, I like to use easy to obtain and relatively cheap materials (hence the plywood

). Hopefully it will encourage players who want a custom instrument regarding string lengths and tuning to build their own instrument.

The instrument is build of two layers of 3/4 inch (18mm) birch plywood. After stumbling on a thread about the thickness of double bass necks, which concluded that a thick neck has some ergonomic advantages over a thin neck, I wanted to try a thick neck (and for simplicity sake leave out the trussrod). After playing with it, I've become really fond of it and would not like anything else any more. I used a roundover bit to round offthe edges of the neck.

String spacing between the strings is that of a 6 string bass, 9mm on the nut side and 18mm on the bridge side.
I used a small piece of plywood to hold the strings in place at the end. The thickest string needed to be a bit shorter so I cut it off and used the internal of a "kroonsteen".

The pick up is a variant of the pick up I've made here. I've wound 800 turns of 0,1 mm wire around neodymium magnets which are glued to two pieces of cardboard. I used two small brass nail heads to connect the wires. The wires are connected to a xlr-connector and plugged in a mic-input. I potted the pickup with transparent waterbased hobby glue.

Posted: **Sat Sep 05, 2015 12:30 pm**

Thanks, that's very cool. Makes me want to experiment a bit with the same idea.

Posted: **Wed Sep 09, 2015 8:05 am**

I'm planning to make prototype 1 of the stick quintar (SQ).
It will be similar to prototype 0, only with 12 strings.
The four lowest string pairs will be in octaves (C, G, D and A) and highest to in unison (E and B).
I've made a simple script for FreeCAD to draw the outline and strings of the SQ.
Although I know the approximate width of the nut and bridge (57mm / 2 1/4", 95mm 3 3/4"), I'm still pondering over the string distance between the corsed strings.
Right now I want to start off with a distance of 2mm (0.079") between the two highest strings and then increase the distance up to 3mm (0.118") between the two lowest strings.
I don't have a twelve string guitar around, so I gladly take some advice on this matter.

Hans
@Admin: is it possible to changes the title of this thread into: Stick Quintar: Prototypes
TIA

Code: Select all

# To do:
# 

App.newDocument("Stick Quintar")

from FreeCAD import Base
import Part, math, datetime, os, copy

# Variables
## Golden ratio
goldenratio = 2.0/(math.sqrt(5.0)-1.0)

## diameter strings
diastr = []
diastr.append(0.132*25.4) 
diastr.append(0.085*25.4)
diastr.append(0.055*25.4)
diastr.append(0.035*25.4)
diastr.append(0.022*25.4)
diastr.append(0.013*25.4)


corsed = 1 # 1=true 0=false
diacorsestr = []
diacorsestr.append(0.060*25.4)
diacorsestr.append(0.040*25.4)
diacorsestr.append(0.026*25.4)
diacorsestr.append(0.018*25.4)
diacorsestr.append(0.01*25.4)
diacorsestr.append(0.013*25.4)

## stringlengths

slbass = 800.0							# stringlength on bassside
sltreble = 800						# stringlength on trebleside
compensation = 2.						# string compensation at the bridge

offsetbridge = (slbass-sltreble)/goldenratio			# Offset off the trebleside
offsetnut = (slbass-sltreble)-offsetbridge 

## Frets
numberfrets = 0
octavedivider = 12.
fretwidth = 1.5

## stringdistance
sdbridgetreble = 12.
sdbridgebass = 12.
factorsd = (sdbridgebass/sdbridgetreble)**(1./(len(diastr)-2.))
sdnuttreble = sdbridgetreble/2.5
sdside = 3.5
sdcorsetreble = 2.
sdcorsebass = 3.
factorsdcorsed = (sdcorsebass/sdcorsetreble)**(1./(len(diastr)-1.))

# width nut and bridge
sdnut = []
sdbridge = []
sdnut.append(0)
sdbridge.append(0)

for i in range(0,(len(diastr)-1)):
  sdnut.append(sdnuttreble*factorsd**(len(diastr)-2-i))
  sdbridge.append(sdbridgetreble*factorsd**(len(diastr)-2-i))

sdcorse = []
sdcorse.append(0)
for i in range(0,len(diastr)):
  sdcorse.append(sdcorsetreble*factorsdcorsed**(len(diastr)-1-i))


widthnut = 2.*sdside+sum(sdnut)+sum(diastr)+sum(diacorsestr)+sum(sdcorse)
widthbridge = 2.*sdside+sum(sdbridge)+sum(diastr)+sum(diacorsestr)+sum(sdcorse)

rcsideneckbass = (-0.5*widthbridge+0.5*widthnut)/(slbass)
rcsidenecktreble = (0.5*widthbridge-0.5*widthnut)/(slbass)

# 
nutoffset = 30.
bridgeoffset = 50.
distancetuners = 125.
enddistance = 25.

#side drawing
xbassQuintarnutend = -nutoffset 
ybassQuintarnutend = -0.5*widthnut+rcsideneckbass*(xbassQuintarnutend)
xbassQuintarbridgeend = slbass+bridgeoffset+distancetuners+enddistance
ybassQuintarbridgeend = -0.5*widthnut+rcsideneckbass*(xbassQuintarbridgeend)
xtrebleQuintarnutend = -nutoffset 
ytrebleQuintarnutend = 0.5*widthnut+rcsidenecktreble*(xtrebleQuintarnutend)
xtrebleQuintarbridgeend = slbass+bridgeoffset+distancetuners+enddistance
ytrebleQuintarbridgeend = 0.5*widthnut+rcsidenecktreble*(xtrebleQuintarbridgeend)

line1 = Part.makeLine((xbassQuintarnutend,ybassQuintarnutend,0),(xbassQuintarbridgeend,ybassQuintarbridgeend,0))
Part.show(line1)
line2 = Part.makeLine((xtrebleQuintarnutend,ytrebleQuintarnutend,0),(xtrebleQuintarbridgeend,ytrebleQuintarbridgeend,0))
Part.show(line2)
line3 = Part.makeLine((xbassQuintarnutend,ybassQuintarnutend,0),(xtrebleQuintarnutend,ytrebleQuintarnutend,0))
Part.show(line3)
line2 = Part.makeLine((xbassQuintarbridgeend,ybassQuintarbridgeend,0),(xtrebleQuintarbridgeend,ytrebleQuintarbridgeend,0))
Part.show(line2)

# frets drawing

for i in range(0,numberfrets+1):
    xbassleft = (slbass-(slbass/2**(i/octavedivider)-0.5*fretwidth))
    ybass = (-(widthnut/2.0+(widthbridge-widthnut)/2.0*xbassleft/slbass))
    xtrebleleft = (offsetnut+sltreble-(sltreble/2**(i/octavedivider)-0.5*fretwidth))
    ytreble = ((widthnut/2.0+(widthbridge-widthnut)/2.0*xtrebleleft/slbass))
    fretleft = Part.makeLine((xbassleft,ybass,0),(xtrebleleft,ytreble,0))
    Part.show(fretleft)
    xbassright = (slbass-(slbass/2**(i/octavedivider)+0.5*fretwidth))
    ybass = (-(widthnut/2.0+(widthbridge-widthnut)/2.0*xbassright/slbass))
    xtrebleright = (offsetnut+sltreble-(sltreble/2**(i/octavedivider)+0.5*fretwidth))
    ytreble = ((widthnut/2.0+(widthbridge-widthnut)/2.0*xtrebleright/slbass))
    fretright = Part.makeLine((xbassright,ybass,0),(xtrebleright,ytreble,0))
    Part.show(fretright)
    

# bridge
xbass = slbass+compensation
ybass = (-(widthnut/2.0+(widthbridge-widthnut)/2.0*xbass/slbass))
xtreble = offsetnut+sltreble+compensation
ytreble = ((widthnut/2.0+(widthbridge-widthnut)/2.0*xtreble/slbass))
bridge = Part.makeLine((xbass,ybass,0),(xtreble,ytreble,0))
Part.show(bridge)

# Strings
# width nut and bridge
#sdnut = []
#sdbridge = []
#sdnut.append(0)
#sdbridge.append(0)
#for i in range(0,(len(diastr)-1)):
#  sdnut.append(sdnuttreble*factorsd**(len(diastr)-2-i))
#  sdbridge.append(sdbridgetreble*factorsd**(len(diastr)-2-i))

for i in range(len(diastr)):
  diastrtemp = diastr[0:i+1]
  sdnuttemp = sdnut[0:i+1]
  sdbridgetemp = sdbridge[0:i+1]  
  diacorsestrtemp = diacorsestr[0:i+1]
  sdcorsetemp = sdcorse[0:i+1] 
  ynut1 = -widthnut/2.0 + sdside + sum(diastrtemp) + sum(sdnuttemp) + sum(diacorsestrtemp) + sum(sdcorsetemp)
  ybridge1 = -widthbridge/2.0 + sdside + sum(diastrtemp) + sum(sdbridgetemp) + sum(diacorsestrtemp) + sum(sdcorsetemp)
  string1 = Part.makeLine((0,ynut1,0),(slbass,ybridge1,0))
  Part.show(string1)
  ynut2 = ynut1-diastr[i]
  ybridge2 = ybridge1-diastr[i]
  string2 = Part.makeLine((0,ynut2,0),(slbass,ybridge2,0))
  Part.show(string2)
  ynut3 = ynut1+sdcorse[i+1]
  ybridge3 = ybridge1+sdcorse[i+1]
  string3 = Part.makeLine((0,ynut3,0),(slbass,ybridge3,0))
  Part.show(string3)
  ynut4 = ynut3+diacorsestr[i]
  ybridge4 = ybridge3+diacorsestr[i]
  string4 = Part.makeLine((0,ynut4,0),(slbass,ybridge4,0))
  Part.show(string4)


Gui.SendMsgToActiveView("ViewFit")
print(widthnut,widthbridge)

Posted: **Wed Sep 09, 2015 1:50 pm**

Rather than FreeCad, you might start with the very friendly http://www.ekips.org/tools/guitar/fretfind2d/ which outputs to PDF, DXF and will let you play with the numbers to your heart's content.

Posted: **Thu Sep 10, 2015 2:45 am**

That's a useful tool indeed David!
I used it as a reference for the script.
I use a different approach for calculating the nut width, which fretfind2d doesn't supplies.
I use the following formula:
Nutwidth = 2*fretboardoverhang + sum(stringgauges) + (number of strings-1)*sidetosidestringspacing.
Because of the big difference in string gauges (a factor 10 between high and low), I want to use an equal spacing between the strings (measured from side to side, instead of measuring from middle to middle).
Further I need to know where I have to cut and file the grooves to place the strings at the side of the nut.

Posted: **Sat Sep 12, 2015 12:22 am**

I'm a big fan of fretfind2d, and though I have done the math to get the nut widths I want (e.g., 1/8" overhang minus standard nut width 1-11/16" equals nut string spacing, then use progressive string spacing ruler), it would be nice to have a simple input for nut width. Still, such a great tool, especially for multi-scale instruments. I've not had need to export as DXF, though, as I've not gotten into much CAD.

Posted: **Sat Sep 12, 2015 9:53 am**

One of the other reasons I developed this script was that I had an idea to make a compound string spacing.
With the fifths tuning I have a wide range and when playing in the bass region I like to get my fingers of my right hand in between the strings to get the right tone, so I need a wide spacing, on the other hand I like to have the treble strings less wide apart for chordal playing.
So I experimented with increasing the string spacing from the highest two strings to the lowest to strings with a certain factor (which gives a exponential increase).

For now I've put aside this idea because when (I try) playing chordal stuff on the fretless Quintar, a wide string spacing is more convenient because playing barre type chords doesn't work so well, so I need to have space to place all my fingers.

I've been thinking over the spacing between the two coursed strings and I think I'll be fine with a string spacing of 2mm for the highest string pair and increasing it stepwise to 3mm for the lowest string pair.

MIMF

Stick Quintar: prototype 0

Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0

Re: Stick Quintar: prototype 0