New Design Proto Build - Lyra

One of the reasons the Lyra body can only be machined on a cnc is the top tuning process. Top carve profile is fixed but the top thickness will be used to tune it like it's done on classical and flamenco guitar tops. I will run the same carving program again and again while changing the depth of cut and tapping to test the tune until I get to the desired Timbre

 

You might be interested in the Bone Voyage build as well which is a 13" arched top build
Here: http://www.tdpri.com/threads/bone-voyage.530380/

 

Fully hollowed arched top

Too many to count. in a few words... semi hollow vs fully hollowed arch top.
I suggest you visit the Bone Voyage build thread to see what it's all about and then wait for this thread to end. At that point you will have your answer.

 

I will not get into detail about the neck as it is mostly similar to my Bone line in design...
Here's a few shots from the process

 

Tops need to be carved now in order to tune them along with the backs.
Initial height set with this template. This is the max size and I will continue to thin the top multiple times until I hit the desired tone as previously mentioned





Tops are cut





Drills and Vent holes are also cut prior to tuning






I repeat the top carving until I get to the desired note and then thickness the back down to match it

 

To isolate the top and back I lay a small cloth rag on the table and set the body on top of it so what I hear is just the top or just the back tapping





Here's the final tuning vids:


The Mahogany top/back







And the maple







Even though the tap volume is about the same between the models, the Maple top timbre is still noticeably different than the Mahogany in both note and color

 

It's a little funny to see the body almost complete but kept in the rectangular blank shape..
The reason for this is the need to have a flat base on the top side to set the body for the back cavities routing





Done






You can now view the floating top from the inside









The STP insert drill is deeper than standard with the opening on the top only being slightly larger to allow the top to freely vibrate while the STP is still anchored to the mahogany core.
This is an important part of the Lyra's design where the strings are anchored like on a solid body but the bridge itself is connected to the floating top to vibrate it properly.

 

Worth mentioning... I have an old original Kalamazoo 335 top I use for templates..etc.. and comparing the thickness I found it to be identical after sanding to the Lyra's sweet spot thickness. Does it mean anything? I don't know but it is interesting.

 

Mortise is cut to accommodate the neck tenon at a low 3.8° angle. I'm using triangular jigs for different angles




Cut







Outline is cut









and the rims are sanded to remove any routing marks to a smooth clean surface

 

The Lyra body will not get any binding. I want a super comfy round-over on the top and back edges.
Plus.. I believe it will look awesome with the deep top re-curves (-;

I will use this dome jig to run the top edge rounding manually






This is a two hand delicate operation so no photos...
but it looks like that when done..








and the back is done normally on a flat table





I stopped the rounding in the middle of the cutaways and will blend them in with a file after the neck is glued and the heel is carved...

 

A few more shots..








The top is floating half way through the tenon

 

Boards are dark Brazilian Rosewood with MOP dots and kept as simple and classic as possible to fit the earthy clean look I'm going for... the Lyra is all about tone and comfort so no real need for fancy stuff (-;




Slotted





Dry fretted with a hammer






and checked for zero bowing after frets are installed





I now inject thin CA glue under the frets





and let it get sucked up to the board surface under the frets







Edges are squared along with the fret ends




Like that





Even though I opted for no binding on the body I still want them on the board but with a very subtle look... as if they are not there.
Here's a beautiful Italian brown celluloid that matches the Brazilian Rosewood color perfectly





Start with the board end edge using clear acetone glue





Trimmed





and sanded flush





Sides follow..





and set aside to cure for a couple of hours






Neck headstocks are widened for the wider Lyra's headstock outline