28.6 Short Scale Bass help needed

[Robert_303]

Hi All,
I am having an issue with a bass I am designing and building and am in need of assistance.

A bit of background, I am pretty well versed in accoustic guitar repair and building. I use to play bass in a band back in the 70's
and recently I got the bug to build one. I played a Squire 28.6" scale little bass I liked it so I decided to design and build one.

I have my neck pretty much done other than fretting and just discovered a slight mistake and want to know if this is going to come
back and bite me..

It is a fender style neck and my drawing has the neck thickness (less fretboard) at the neck pocket is suppose to be 0.93" With fret-board it is 1.118"

I managed to make it 0.85" With Fretboard 1.034 A 0.084 difference.

What I am trying to figure out is if this is going to cause issues. By shaving off roughtly 0.1 from the neck thickness I will need to make my neck pocket
that much shallower to compensate for my mistake. This will put the face of the headstock 0.1" higher and my concern is there will not be enough
break angle from the nut to the pegs.

Here are a couple of screenshots of my isssue. At the neck pocket you can see the double line where I cut the neck to thin.

(I have the critical measurements in red)

Thanks for any help you can give.

Cheers,
Bob

 

[Bruce Johnson]

Hi All,
I am having an issue with a bass I am designing and building and am in need of assistance.

A bit of background, I am pretty well versed in accoustic guitar repair and building. I use to play bass in a band back in the 70's
and recently I got the bug to build one. I played a Squire 28.6" scale little bass I liked it so I decided to design and build one.

I have my neck pretty much done other than fretting and just discovered a slight mistake and want to know if this is going to come
back and bite me..

It is a fender style neck and my drawing has the neck thickness (less fretboard) at the neck pocket is suppose to be 0.93" With fret-board it is 1.118"

I managed to make it 0.85" With Fretboard 1.034 A 0.084 difference.

What I am trying to figure out is if this is going to cause issues. By shaving off roughtly 0.1 from the neck thickness I will need to make my neck pocket
that much shallower to compensate for my mistake. This will put the face of the headstock 0.1" higher and my concern is there will not be enough
break angle from the nut to the pegs.

Here are a couple of screenshots of my isssue. At the neck pocket you can see the double line where I cut the neck to thin.

(I have the critical measurements in red)

Thanks for any help you can give.

Cheers,
Bob

Hello Bob;

Welcome to Luthier's Corner! Where we thrive on discussing the engineering details of electric basses.

About your headstock depth/string break angle problem: Yes, as shown on your drawing, the break angle is less than desirable. But it will probably function okay as long as you wind the strings downwards on the posts. Three to five wraps, with the string coming off of the bottom wrap. That should give you enough break angle.

A related issue is the thickness of your headstock. 1/2" is thin for an electric bass. Most bass headstocks are 9/16" to 5/8" thick, and that's what standard tuners are designed for. That's also contributing to your tuners being raised up vertically, reducing the break angle.

I suggest adding 1/8" thick slice of maple or a decorative stack of veneers onto the back of the headstock. That will strengthen the headstock and move the tuners down.

 

[Beej]

Hi Bob, I have a handful of thoughts:

First thought: 1.034 - 0.85 is actually 0.184, which is quite a bit more than 0.084

2nd thought: I would not get too hung up on the difference in height over the neck pocket with concern about the neck pocket itself, the more important consideration is "will the strings lay completely flat/slack against the fretboard when the saddles are lowered all the way?" If the answer is no, then you (or a future owner) run the risk of breaking the truss rod trying to get the right relief in the neck. I can explain this more if it doesn't make sense!

3rd thought: I'm not sure why the depth at the heel would have anything to do with the headstock. These aren't necessarily functions of one another - I would advise keeping your headstock thickness/depth as originally designed. That said, if it does end up being thinner than you designed/intended, then it's worth noting that the critical minimum breakover angle has been researched to be 4.25 degrees. Ken Parker did extensive experimentation with breakover angle at the nut, and landed on 4.25 degrees as the minimum angle to have at that point in order to prevent sympathetic resonance in the strings, and also the minimum angle to ensure the string is held in position.

 

[Beej]

Bruce and I responded at the same time - he's got sage advice! With the tuners I prefer (Gotoh GB350), the minimum headstock thickness is 14mm, but it's good to be safer than sorrier...

 

[Robert_303]

Thank you guys for the response,

@Bruce Johnson
I am not sure where the 1/2" headstock came from but adding a backstrap is probably the best choice to fix that issue. I just noticed
after you pointed that out that my HIpshot Ultralite tuners just bottom out when tighting them down. So thanks for pointing that out.

@Beej
you said:
will the strings lay completely flat/slack against the fretboard when the saddles are lowered all the way?"

The way it is right now on the drawing the strings are just over 3/64ths off the frets. I figured that was lower than you would normally set a bass up.

3rd thought: I'm not sure why the depth at the heel would have anything to do with the headstock.

Because I cut the neck blank 0.1" thinner than it should have been, the bottom of the heel and the back of the neck blank are on the same
plane. So in essence my headstock is 0.1" higher than it should be.

Thank you guys for the help.

Cheers,
Bob

 

[Beej]

Thank you guys for the response,

@Bruce Johnson
I am not sure where the 1/2" headstock came from but adding a backstrap is probably the best choice to fix that issue. I just noticed
after you pointed that out that my HIpshot Ultralite tuners just bottom out when tighting them down. So thanks for pointing that out.

@Beej
you said:
will the strings lay completely flat/slack against the fretboard when the saddles are lowered all the way?"

The way it is right now on the drawing the strings are just over 3/64ths off the frets. I figured that was lower than you would normally set a bass up.

3rd thought: I'm not sure why the depth at the heel would have anything to do with the headstock.

Because I cut the neck blank 0.1" thinner than it should have been, the bottom of the heel and the back of the neck blank are on the same
plane. So in essence my headstock is 0.1" higher than it should be.

Thank you guys for the help.

Cheers,
Bob

Ah, my bad, I missed that you'd already cut the neck out! I agree that a veneer or two on the back should help with the headstock thickness.

Regarding the relief, you're right that 3/64" may be more than enough for adequate relief, but we've seen TR breakage here before from folks who were trying to get the lowest possible action, however couldn't get the strings to lay flat because the built-in height above the frets when the saddle was at it's lowest. It stymied them and they kept on cranking until 'snap'. On a side note, a guy who's guitars/basses I set up, likes his action low enough that it buzzes on many frets, and this buzzing, clanking mess contributes to his 'unique tone'.

 

[Robert_303]

@Beej

Yea it looks like I will have to put a back strap on the headstock and the heel, I am building the body out of Walnut so it will probably look good capped in the same. Sometimes mistakes can be "features"...

So when you set your neck position the strings are laying right on the frets?

Cheers,
Bob

 

[Matt Liebenau]

@Beej

Yea it looks like I will have to put a back strap on the headstock and the heel, I am building the body out of Walnut so it will probably look good capped in the same. Sometimes mistakes can be "features"...

So when you set your neck position the strings are laying right on the frets?

Cheers,
Bob

Yes, generally, for me at least, I’d like the bridge saddles in their lowest position to have the strings just touching the frets. When building or checking things I run a straight edge along the fretboard and it should just touch where the string breaks off of the saddle with the saddle or bridge in its lowest position. That’s an ideal anyway. Bass or guitar.

 

[Beej]

@Beej

Yea it looks like I will have to put a back strap on the headstock and the heel, I am building the body out of Walnut so it will probably look good capped in the same. Sometimes mistakes can be "features"...

So when you set your neck position the strings are laying right on the frets?

Cheers,
Bob

ooh, please share the build here, plenty of us are serious fans of walnut.

And yes, I make sure the strings can lay flat against the fretboard on my bass builds. Here's a sad cautionary tale from @Rôckhewer

Thread 'Balance K Tribute repair & major MOD'

Feb 25, 2021

Greetings.
I promised to share.. (warts and all)... so here we go.
My full evaluation/ explanation of the problem that resulted in the broken rod... will be revealed forthcoming in this thread.
As will the cool modifications that are happening to this bass. (So... this is also kind of a build thread.)
But for right now?
I'd appreciate anyone of my "tribe" of friends and associates here.... who are so inclined to throw out a prayer/ chant / dance/ or voodoo spell of well wishes? To please do so now.
This wenge board is coming off.
Pretty sure I'm...

• Rôckhewer
• Replies: 146
• Forum: Luthier's Corner

• 

The explanation begins at post 29

 

[Rôckhewer]

Here's a sad cautionary tale from @Rôckhewer

Meh... it was about this fun:

Thanks for the memories @Beej