35" scale P bass question

[rubis]

I wonder if I might ask for your help in relation to 35" scale basses, in this case a P style which I have began to build
Is the body the same size as a standard 34" scale P bass, or is it longer, I would assume by 1/2" to accommodate half of the extra inch
The second question I have is what is the measurement from the 12th fret to the split between the two halves of the pickup, this to allow me to place it correctly and (hopefully) retain the authentic sound
Thank you kindly for your help

 

[Beej]

Well, 35" is 2.85% larger than 34", so you could expand your dimensions by 2.85% in order to accommodate the extra length. You may want to make sure that it will still fit in a standard case if that matters to you.

From a very oft quoted thread on the topic of pickup locations:
"from the nut side of the 12th fret to the E/A pole-piece centers is 11.000 inches . . . from the nut side of the 12th fret to the D/G pole-piece centers is 12.1875 inches"

So that would be 11.3135" and 12.534" respectively.

 

[Bruce Johnson]

Well, if you are designing the bass all yourself, you can decide how much of the extra inch of scale length is on the neck, and how much is on the body. You can make up a special 35" scale neck which will fit on a standard 34" scale length body, if you want to.

But, I'll assume that you want to build your 35" scale P-bass to be proportionally and geometrically like a normal 34" P-bass. In that case, the new body will need to be slightly longer, but not quite 1/2".

A standard 34" P-bass neck is 20 frets, and the back end of the heel is at the 21st fret position. It measures 23.892" from the zero line (front edge of the nut) to the end of the heel. A 35" version of that neck would measure 24.595" to the end of the heel. The 35" neck is 24.595"-23.892" = 0.703" longer.

That means that the bridge needs to move back 1.000" - 0.703" = 0.297" on the body. A little less than 5/16". You can probably move the bridge back that far on a standard size P-bass body, but if you want to keep it all proportional looking, you could extend the back end of the body about 5/16".

Beej covered how to measure the pickups. Measure their locations on a 34" scale P-bass, from the 12th fret. Then expand that dimension by a proportion of 35/34.

 

[dwizum]

I don't know if the 2.85% method is completely legitimate. The thing that probably matters is the relative position as a percent of the scale length, not the distance from a fixed point on the scale length.

 

[dwizum]

I thought through that and actually wrote the math out and basically realized I was wrong. You can still apply 2.85% to the 11" from the 12th fret because the 12th fret on the 35" scale length is already 2.85" further from the nut.

So basically, ignore what I said...

 

[rubis]

Beej, Bruce Johnson and dwizum you are all perfect gentlemen, thank you all very kindly
Have a great Christmas