Body Design rule-of-thumbs?

[WilbursaurusRex]

Hey yall, I’ve been working off and on with my first design/build. I know, generally speaking, putting the upper horn ~12 fret is good for balance, but started wondering if there were any more “rules-of-thumb” that are good to stick too when designing a body shape, and help avoid headaches down the line.

For example, I’m laying everything out on a centerline, but I noticed the upper horn/bout are .5” further from CL than the lower horn/bout. When referencing my pbass I noticed the upper vs lower were pretty much the same from CL. Is that a no no? Bridge, pickup, neck/neck pocket are all on CL

 

[ardgedee]

For example, I’m laying everything out on a centerline, but I noticed the upper horn/bout are .5” further from CL than the lower horn/bout. When referencing my pbass I noticed the upper vs lower were pretty much the same from CL. Is that a no no? Bridge, pickup, neck/neck pocket are all on CL

In design (which encompasses what you're doing) we have a concept of "optical center" which is different from the literal center. Almost always, to make an asymmetric shape look balanced you have to scooch the whole thing to the left or right (or up or down) a bit relative to the things around it or in it.

To pile on to that, when you're building an object that interacts with the body (like an electric bass), you also have to compensate for the human who's going to use it. So you might have to move things even more out of proportion one way or another to make it feel comfortable, or to accommodate reach to the first fret or to give the picking hand more freedom.

So the tl;dr answer is: "If it looks good, don't worry about it," but if you're willing to dig in a little deeper, you'll be able to learn a lot about why the instruments you like look the way they do.

 

[WilbursaurusRex]

In design (which encompasses what you're doing) we have a concept of "optical center" which is different from the literal center. Almost always, to make an asymmetric shape look balanced you have to scooch the whole thing to the left or right (or up or down) a bit relative to the things around it or in it.

To pile on to that, when you're building an object that interacts with the body (like an electric bass), you also have to compensate for the human who's going to use it. So you might have to move things even more out of proportion one way or another to make it feel comfortable, or to accommodate reach to the first fret or to give the picking hand more freedom.

So the tl;dr answer is: "If it looks good, don't worry about it," but if you're willing to dig in a little deeper, you'll be able to learn a lot about why the instruments you like look the way they do.

Ah ok, that makes sense. I tried making the contours off CL and it looked awful!
Any good resources you’d recommend? I really do like learning about this stuff, and I feel it helps us make more intentional design choices.


Here’s a pic btw. Don’t mind the spline at the neck heel. I haven’t gotten around to that part yet

So CL to upper half is ~.5” more than CL to lower half

 

[ardgedee]

Any good resources you’d recommend? I really do like learning about this stuff, and I feel it helps us make more intentional design choices.

Nothing offhand, it's been a (cough) couple-ish (cough) decades since I was last taking classes.

What I would suggest, for starters, is try looking at it in different ways. Color it in, rotate it, mirror it, rotate that, try different backgrounds... keep making it seem new without actually changing it, this will make different aspects more noticeable, you might see something about it that hadn't registered before.

Also try cutting a mockup out of cardboard or styrofoam to see how it feels.

 

[ardgedee]

I'll also add: Design is iterative. You try something, make notes of where it works and doesn't work, make changes and try again. Nobody gets it right the first time. Experience can help cut the process shorter but you're just starting out, so take it easy and learn how to simultaneously criticize and appreciate the bass you're designing, as well as any other basses you see.

 

[gormsby]

I'll throw in a few. They may seem 'no-duh' obvious, but having them on a checklist never hurts and can prevent some oversights.

• Lower bout should be large enough to accommodate your planned controls, well arranged, and leave enough room for whatever contouring you have planned (minimal on an FSO, potentially a lot on a modern, e.g. SR-style.)
• If you want to play it seated without a strap, make sure the lower horn length and angle allow the instrument to rest securely on your leg (I have a guitar that only just balances/teeters on my lower leg and don't like that fact, though I'm living with it because I love the guitar.)
• Thick enough to allow pickups and (more importantly) the pickup mounting screws to work well at needed depth and not poke through the back.)
• For hollow or semi-hollow body designs, make sure to leave top/bottom thickness where needed for any contouring.

 

[frets4ever]

Ah ok, that makes sense. I tried making the contours off CL and it looked awful!
Any good resources you’d recommend? I really do like learning about this stuff, and I feel it helps us make more intentional design choices.


Here’s a pic btw. Don’t mind the spline at the neck heel. I haven’t gotten around to that part yet

View attachment 7504281

So CL to upper half is ~.5” more than CL to lower half

What software are you using for your drawings?

 

[Beej]

A few things that have solidified for me over the years and various design iterations:

• A full design is better than designing a body and neck separate from one another, as they can diverge in their 'goodness of fit' with one another.
• Symmetry is not necessary, but it's visually pleasing. Visual balance does a similar thing. A p-bass is not symmetrical, but it does appear visually balanced. The Ibanez EHB looks like blue whale genitalia to me. I can't unsee it. Some don't care at all, but some are sensitive to the overall visual balance.
• The upper horn to 12th fret 'rule' only works if the bridge is also located near the tail of the body. If you bring the bridge inward, the horn will need to reach further. The longer the horn, the more the bass can feel 'tucked in', to a point. I like my bridges at the tail, and my upper horns to reach to the 10th fret.
• The neck 'beam' (tip to tail of body) is where your hands will reach. The bouts on the body can be positioned along that beam with different effects. If you have a shorter upper horn, on a strap, it will effectively place the headstock further away from your body. Good or bad depends on your body, your reach, and your accustomed technique.
• Physical balance of the instrument is also helpful to make it heft in the hands nicely, and to sit against your body in a nice way.
• Belly cut and arm bevel make a big difference in comfort for many body types (but not all).
• Weight matters when it comes to playability. You may not care, and if it's for you, great, but there's a reason why weight is listed on so many sales platforms. Don't be fooled into thinking this is just a TB thing - in real life, most bass players are not on TB. Weight affects balance and comfort.
• Think about the design in full 3D, including what's going on inside the body and neck. Being aware of this helps plan for how it all comes together.
• For visual pleasure, I've noticed that I prefer it when the horns are closer to the centerline than the bouts.

That's some general stuff, here are specifics that I've landed on through the iterative process of building. Some I think apply universally, some I think are just because I dig them:

• Tilt back headstock (avoids string trees; keep the angle to 7ish degrees to fit in existing cases)
• Small, light headstock (helps overall balance)
• Straight string pull
• Veneer top/back caps (hides stringers)
• Volute (thumb stop placing index finger on first fret)
• Zero fret (I like them, good topic to research)
• Multi-stringer neck construction (increases stability)
• Tapered middle stringer (they look hawt)
• Stabilizing rods (CF or aluminum; increase stability seasonally and with temp changes)
• Epoxy-bedded double-acting truss-rod
• 24 frets
• Chambered body
• Radius top and upper back
• 5/8" partial roundover
• Feathered edge at arm 'bevel'
• Magnet-mounted control covers
• Block-mounted bridge (embedded aluminum or brass block; bridge bolted to it)
• Locking strap buttons

Plan things out, play basses, take measurements, think about what you like and why you like it, and then build the best bass for you that you can build.

 

[Thumpin6string]

I hate rules.

 

[Gilmourisgod]

@Beej covered it admirably, the only thing I'd add is get to full sized templates right away. You can fool yourself about proportions looking at a screen. Most big box stores sell "handi-panel" 2'x4' or 4'x4' pieces of MDF, which is relatively cheap and easy to cut and form, and if you screw it up, no big deal. On to the next. When you arrive at a final design you are really happy with, soak the edges of the MDF by putting some water-thin CA glue on, hardens the edges up nicely. Neck divers are a personal peeve of mine, but it's hard to determine balance until you have all the parts in hand. I've laminated pieces of plywood or MDF together to make a pretty realistic mockup of a body design, not a perfect analog, but it was at least a decent snapshot of how a body design would hang, or sit on a knee for seated playing. Good luck with it!

 

[BassUrges]

It's a lot of work, but I like to make a full 3D model of anything I'm building. That makes it easy to rotate, view from different angles, and so on, but more importantly, makes modification and addition easy. Tuners you wanted to use discontinued? Well, check if the available ones fit and make tweaks. Want to design a custom stand around your unique contours? Conveniently modeled for you to work with. Need to make a template to repair unexpected damage? Etc.

I use Fusion 360, free for hobbyists

 

[T_Bone_TL]

Try to make all the mistakes on paper, where/when correcting them is easy. You probably won't, but try...

Working through cardboard, MDF &/or pine (or whatever wood is cheap/free for you - house-framing scraps can be awesome) mockups may help to find mistakes not obvious on paper, without negatively impacting the real thing when you get there.

 

[micguy]

A couple of minor points:

1) Put the bridge as close to the butt end of the body as you can. Every inch you move it away from the butt end adds to the reach to the first fret. There are a lot of short scales that don't do this, and as a result, the reach is often almost as much as it would be on a full scale (which, to me defeats a large part of why a short scale exists). Exhibit A of this lunacy:

2) Most basses have a strap button on the upper horn, and another at the butt end, on the centerline. OK, but if you move the one on the butt end up off the centerline an inch or two, it makes the bass more stable as far as leaning forward (most basses have more weight on their faces than their backs). This is a minor point, but it helps things a little.

 

[WilbursaurusRex]

What software are you using for your drawings?

Fusion 360

A few things that have solidified for me over the years and various design iterations:

• A full design is better than designing a body and neck separate from one another, as they can diverge in their 'goodness of fit' with one another.
• Symmetry is not necessary, but it's visually pleasing. Visual balance does a similar thing. A p-bass is not symmetrical, but it does appear visually balanced. The Ibanez EHB looks like blue whale genitalia to me. I can't unsee it. Some don't care at all, but some are sensitive to the overall visual balance.
• The upper horn to 12th fret 'rule' only works if the bridge is also located near the tail of the body. If you bring the bridge inward, the horn will need to reach further. The longer the horn, the more the bass can feel 'tucked in', to a point. I like my bridges at the tail, and my upper horns to reach to the 10th fret.
• The neck 'beam' (tip to tail of body) is where your hands will reach. The bouts on the body can be positioned along that beam with different effects. If you have a shorter upper horn, on a strap, it will effectively place the headstock further away from your body. Good or bad depends on your body, your reach, and your accustomed technique.
• Physical balance of the instrument is also helpful to make it heft in the hands nicely, and to sit against your body in a nice way.
• Belly cut and arm bevel make a big difference in comfort for many body types (but not all).
• Weight matters when it comes to playability. You may not care, and if it's for you, great, but there's a reason why weight is listed on so many sales platforms. Don't be fooled into thinking this is just a TB thing - in real life, most bass players are not on TB. Weight affects balance and comfort.
• Think about the design in full 3D, including what's going on inside the body and neck. Being aware of this helps plan for how it all comes together.
• For visual pleasure, I've noticed that I prefer it when the horns are closer to the centerline than the bouts.

That's some general stuff, here are specifics that I've landed on through the iterative process of building. Some I think apply universally, some I think are just because I dig them:

• Tilt back headstock (avoids string trees; keep the angle to 7ish degrees to fit in existing cases)
• Small, light headstock (helps overall balance)
• Straight string pull
• Veneer top/back caps (hides stringers)
• Volute (thumb stop placing index finger on first fret)
• Zero fret (I like them, good topic to research)
• Multi-stringer neck construction (increases stability)
• Tapered middle stringer (they look hawt)
• Stabilizing rods (CF or aluminum; increase stability seasonally and with temp changes)
• Epoxy-bedded double-acting truss-rod
• 24 frets
• Chambered body
• Radius top and upper back
• 5/8" partial roundover
• Feathered edge at arm 'bevel'
• Magnet-mounted control covers
• Block-mounted bridge (embedded aluminum or brass block; bridge bolted to it)
• Locking strap buttons

Plan things out, play basses, take measurements, think about what you like and why you like it, and then build the best bass for you that you can build.

Thank you for going into so much detail! Yes, I dont care too much for the EHB but I dont find it that offensive I also like the idea of a zero fret and am planning on incorporating one

It's a lot of work, but I like to make a full 3D model of anything I'm building. That makes it easy to rotate, view from different angles, and so on, but more importantly, makes modification and addition easy. Tuners you wanted to use discontinued? Well, check if the available ones fit and make tweaks. Want to design a custom stand around your unique contours? Conveniently modeled for you to work with. Need to make a template to repair unexpected damage? Etc.

I use Fusion 360, free for hobbyists

Yes, Im using Fusion as well. Im working toward a full 3d model but working on things a little here a little there to make sure things are staying in relation and proportion as Im working through it.

A couple of minor points:

1) Put the bridge as close to the butt end of the body as you can. Every inch you move it away from the butt end adds to the reach to the first fret. There are a lot of short scales that don't do this, and as a result, the reach is often almost as much as it would be on a full scale (which, to me defeats a large part of why a short scale exists). Exhibit A of this lunacy:

View attachment 7504895

2) Most basses have a strap button on the upper horn, and another at the butt end, on the centerline. OK, but if you move the one on the butt end up off the centerline an inch or two, it makes the bass more stable as far as leaning forward (most basses have more weight on their faces than their backs). This is a minor point, but it helps things a little.

Ive noticed this as well and it is a bit odd. You get the benefit of having the frets a little closer together, but keep the about the same reach. The one Im working on is intended to be a 32" scale.


Man, Im so thankful for the shared insights! Thank yall so much.

 

[Dave Higham]

Try to buy all the hardware and electronics, tuners, bridge, truss rod, pickups, pots, etc. before you start cutting wood. It avoids finding out that things you thought would fit, don't, or are no longer available, etc. It's happened to me!

 

[Beej]

I don't mind the Ibanez EHB; they play great. They just appear 'biological' to my eye.

 

[frets4ever]

Fusion 360




Thank you for going into so much detail! Yes, I dont care too much for the EHB but I dont find it that offensive I also like the idea of a zero fret and am planning on incorporating one




Yes, Im using Fusion as well. Im working toward a full 3d model but working on things a little here a little there to make sure things are staying in relation and proportion as Im working through it.




Ive noticed this as well and it is a bit odd. You get the benefit of having the frets a little closer together, but keep the about the same reach. The one Im working on is intended to be a 32" scale.


Man, Im so thankful for the shared insights! Thank yall so much.

The most important thing for me is to use the origin point as my center line. The center of the body end is my XY=0 datum point. Also g coding is easier so if you ever plan on using a cnc machine at some point.

What I like to do in Fusion is to create sketch folders for different elements of the guitar or bass. Such has hardware - what i do is use the manufacturer's drawings scaled to 1:1. So one folder will have five or six different bridges that I can hide and unhide, another for pickups and etc. Another thing I will do is create reference folder for a example a Fender bass, plenty of pdf files available that i use for reference as to shape hardware, pots and etc.

Looking at the design on the screen can be misleading. That is why I will printout the designs as I go along to mock up the bridge, pickups and pots. Before making changes, I will always copy the previous version and work on the copy.

 

[WilbursaurusRex]

The most important thing for me is to use the origin point as my center line. The center of the body end is my XY=0 datum point. Also g coding is easier so if you ever plan on using a cnc machine at some point.

What I like to do in Fusion is to create sketch folders for different elements of the guitar or bass. Such has hardware - what i do is use the manufacturer's drawings scaled to 1:1. So one folder will have five or six different bridges that I can hide and unhide, another for pickups and etc. Another thing I will do is create reference folder for a example a Fender bass, plenty of pdf files available that i use for reference as to shape hardware, pots and etc.

Looking at the design on the screen can be misleading. That is why I will printout the designs as I go along to mock up the bridge, pickups and pots. Before making changes, I will always copy the previous version and work on the copy.

Yeah, choosing where to put my origin point was a challenge since Ive been mocking up neck and body together instead of doing separate files. I intend to break those apart and probably change the body origin point before moving on to programming. Ive tried mocking up some tuners based off a print, but havent done a bridge yet.

Im hoping to print off and mock up some body variations over the next few weeks to get a better idea of how things will sit.

 

[Gary_M]

I think everyone has covered the primary considerations. Here are a couple more practical things to keep in mind.

1. Make sure it fits in a standard case or bag.
2. Do not shape it like a Stratocaster.

 

[Cran]

Only adding this on because I haven't seen anyone mention it, and because I'm struggling with it on my current build - leave enough space between the bottom horn and the fretboard for the whole hand the fit comfortably. Otherwise reaching the high frets becomes a nightmare. There's a reason most designs are made to allow so much movement in that area.