# Skylis Guitars headless ergonomic basses (NAMM 2018)



## ixlramp (Jan 29, 2018)

For me the most interesting bass at NAMM so far. What i appreciate:

Headless.
Simple and elegant body design.
Long top horn reaching to the 11th fret, but also kept close to the neck to improve balance at high angles.
Compared to a conventional 'linear' bass design, the string axis is, in a way, at an angle to the body.
String axis runs close to the leg when sitting, allows a steeper neck angle when sitting.
Lower horn at a large angle to the string axis, so stable when sitting with the neck at a high angle.
Tuner knobs are recessed so more protected against unwanted contact.

https://www.skylisguitars.com/


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## lewis (Jan 29, 2018)

ixlramp said:


> View attachment 58779
> 
> 
> For me the most interesting bass at NAMM so far. What i appreciate:
> ...


i love it!!

is that pickup position odd though?


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## MaxOfMetal (Jan 29, 2018)

Not digging the shape.

I'd be interesting to see how it looks with a full scale.


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## jephjacques (Jan 29, 2018)




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## LordCashew (Feb 4, 2018)

Looks to me like that body is based on the continental United States...


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## Hollowway (Feb 4, 2018)

Don't tease me like that, ixlramp! I fully expected a 13 string instrument or something in here.


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## Lemonbaby (Feb 5, 2018)

Hmmm, not exactly what I'd call good looks. Reminds me a little of Claas guitars who exist in the same parallel universe of wierd-shaped instruments...


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## r3tr0sp3ct1v3 (Feb 5, 2018)

Oh I thought someone had captured someone standing in front of them. That's an interesting body though.


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## Esp Griffyn (Feb 6, 2018)

jephjacques said:


>



Do as you did for Rom and grant us eyes, grant us eyes!

Seriously though these basses might be a clever design but wow they're ugly.


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## KnightBrolaire (Feb 6, 2018)

jephjacques said:


>


And suddenly I feel the need to play bloodborne


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## BigViolin (Feb 8, 2018)

I'm intrigued by these for the same reasons as OP, especially the neck angle. Would love to play one and hope the build quality matches the price. Cool stuff.

Looking forward to more pics and the full website.


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## Winspear (Feb 9, 2018)

That's an interesting point about neck angle. I only play in classical position/high strapped standing anyway, and never really thought about the horn being closer to the neck causing that effect - though I have thought about turning the neck at an angle like you said it is similar to.


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## ixlramp (Feb 10, 2018)

Likewise having the rear strap button higher above the guitar centreline helps too. The tradition is it being on the centreline, don't know why, probably no good reason.

Balance at different angles is down to the positions of the strap buttons relative to the centre of mass.

To calculate strap balance:

Consider the torques around the COM point caused by the forces exerted on the strap buttons by the strap ends.
Because the guitar is not rotating the torques must be equal and opposite.
Torque at a point is the distance from COM to strap button multiplied by the component of the strap force perpendicular to the line between COM and strap button.

In the image below torque around point 'O' is
r * F * sin(theta)
where
'F' is the force
'theta' is the angle between 'r' and 'F'.




From this you can calculate the ratio of the forces, which gives you the imbalance of pull on each end of the strap.

You can find the COM by holding the guitar horizontal using your hand on the bottom of the bass, shift your hand until the guitar remains precisely horizontal and stable, your hand will then be directly under the COM.
Do the same with the guitar precisely vertical and you get 2 vertical lines crossing the guitar, the COM is at the intersection.

The optimum is equal pull force on each end of the strap, or as equal as possible over the range of used guitar angles.

The optimum design for perfect balance at a wide range of angles is (with the guitar at average playing angle) to have the buttons horizontally level with and equal distance either side of the COM. Only WarrGuitars and Touchguitars use this system, see photos here http://www.touchguitars.com/models-specs/u8-deluxe/
The first minute of this video demonstrates the stability at various angles and shows the strap attachment:


For a guitar usually played at a high neck angle this could be done with 1 button on the back of the lower horn, another on body front at the top about halfway along the body.

I must admit i am obsessed with designing guitars to be stable and positioned well both on your legs or strapped on, i think about it in bed at night. I have some good ideas and want to build guitars but currently having no income and no workshop this is unlikely.


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## ixlramp (Feb 11, 2018)

In that diagram there is the effective lever arm 'd', the perpendicular distance from 'O' to the line of action of the force.
Usefully 'd' just happens to be:
r * sin(theta)
So the torque can be rewritten as
F * r * sin(theta)
= F * d

Now for a guitar we have 2 opposite torques that are equal:
F1 * d1 = F2 * d2
Re-arrage:
d1 / d2 = F2 / F1
So:
'The ratio of pull forces on the ends of the strap is equal to the ratio of the lengths of the effective lever arms'.

When in perfect balance the pull forces on each end of the strap are equal:
F1 = F2
F2 / F1 = 1
d1 / d2 = 1
d1 = d2
'In perfect balance the lengths of the effective lever arms will be equal'.

Once you know the COM position you can visualise the 'lines of action' of the forces and the lengths of the lever arms and judge the balance. When you do this for most mainstream guitars you can see how rapidly the guitar becomes unstable at high neck angles. Most guitars are sightly unstable when horizontal and it only gets worse from there.


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## Andromalia (Feb 11, 2018)

Uh...maths. X_X


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## ixlramp (Feb 11, 2018)

It results in a simple way to visually calculate:




1. Find the centre of mass as described in a previous post.
2. With the instrument at the playing angle you want to analyse, draw vertical lines (blue lines) through the buttons (green dots), these are the 2 forces of the strap ends pulling upwards on the buttons.
3. Draw a horizontal line (blue line) through the centre of mass (green dot).
4. The 2 'effective lever arms' are the red and yellow sections of the horizontal line, their relative lengths show the relative sizes of the forces on each end of the strap.

Here the red line is twice the length of the yellow line, so there will be twice as much force (or weight) on the horn end of the strap as on the rear end of the strap (neck heavy).
The shorter the yellow line is relative to the red line, the more force there is on the horn end of the strap relative to the rear end of the strap.
If the guitar was perfectly balanced the red and yellow lines would be equal lengths.

You can see how the imbalance gets rapidly worse at higher playing angles. At 45 degrees the yellow line becomes very short, so almost all the weight of the guitar is on the horn end of the strap.
Even when horizontal it is still somewhat neck heavy.


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## ixlramp (Aug 23, 2018)

Found some better photos at last.
https://www.instagram.com/skylisguitars/




Looks very comfortable to play sitting.

I like the idea of the strings being as low as possible over the right thigh, this does 2 good things:
1) It automatically creates a more neck-up angle, which is more ergonomic, healthier and more comfortable for the fretting arm.
2) Together with the low-profile body it lowers the plucking arm so that the upper arm doesn't need to be raised so much, again healthier and more comfortable. Also tends to straighten the plucking wrist.

https://www.facebook.com/skylisguitars


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## exo (Aug 24, 2018)

Ergonomic or not, that is still a sin ugly body shape.


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## ElRay (Aug 26, 2018)

ixlramp said:


> ... I must admit i am obsessed with designing guitars to be stable and positioned well both on your legs or strapped on ...




Same here. I’ve been thinking and sketching “stealth ergo” bodies. Not ergot that look like Stealths, but bodies the will sit in a good classical position, but don’t look like an ergo body. Trying to keep form without sacrificing function. 

The other thing I’ve been thinking about is to totally forego the guitar strap and use a sax-strap. Something hanging over two shoulders (like a backwards backpack) will be a lot more stable and ergonomic. The “hanger” just needs to be above the CoM. The only real issue is that the body has to be able to able to counter neck dive and make sure that the guitar will actually be in a playable position. 

If you’re just going for stability when seated, as long as the CoM is between the knees, you’re GtG (good to go).


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## ElRay (Aug 26, 2018)

exo said:


> Ergonomic or not, that is still a sin ugly body shape.


Too far to the left in function VS. form for many. 

I like it being played while seated, but for most, it’s not something to hang in the wall.


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## exo (Aug 26, 2018)

ElRay said:


> Too far to the left in function VS. form for many.
> 
> I like it being played while seated, but for most, it’s not something to hang in the wall.



Aesthetics and ergonomics don’t always meet in the middle


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## exo (Aug 26, 2018)

ElRay said:


> Too far to the left in function VS. form for many.
> 
> I like it being played while seated, but for most, it’s not something to hang in the wall.



Aesthetics and ergonomics don’t always meet in the middle


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## I play music (Aug 26, 2018)

ElRay said:


> Too far to the left in function VS. form for many.
> 
> I like it being played while seated, but for most, it’s not something to hang in the wall.


I buy my instruments to play them, not to hang them on the wall.


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