Orthus - a lap slide guitar
Updated 25th March 2008
Inspired by the fabulous instrument made by the New Zealand builder Paddy Burgin and nagged by my daughter Martha to make her one as soon as she saw the clips Paddy posted of him playing it on Youtube, I've embarked on making a double necked acoustic lap-slide guitar. As usual I want to do this my own way and in my own style. After playing around with different concepts, I've decided to make it a similar size to my Red Kite, but to go with a ladder braced top and one soundhole. The working title for the instrument, therefore, is Bicyclops - I'm sure that Martha will think of something better eventually.

Well, she did, and as of 4th February it is called Orthus - in Greek mythology he was the two headed, serpent tailed dog of Geryon, the three headed giant king of Erytheia. Orthus was also the father of the Sphynx.

	As usual I start with a "cunning plan". This gives me the basics and the plan will evolve as the build progresses.
	Here's the wood that will be used for the top, back and sides. It's two harp guitar sized sets of Khaya (African Mahogany).
	The peg-heads are a good place to start. They ate cut from one block of mahogany . . .
	. . . like so!!
	After they have been cut to shape, the Brazilian Rosewood overlays are glued on using fish glue. The one on the left is yet to be glued up.
	Here are the pegheads after rough shaping and drilling the tuner holes.
	How may luthiers does it take to change a light-bulb? Just one but they have to make a jig first. Well teo actually, one a mould . . .
	. . . and the second one a bending form for the sides.
	The sides are then bent in the Fox bender using the form. A tricky process with lots of clamps.
	Here are the sides out of the Fox bender. They will need touching up on the hot pipe.
	The headstocks are glued to the sides.
	The sides aren't long enough and a third piece is required. Two lime end-blocks have been made and the sides are glued to these. You can see the "neck-block in the picture. The sides are glued into slots in the neck-block and slots have also been cut for two carbon fibre flying buttress braces that will be anchored at the sides. The neck-block hasn't been glued to the sides yet.
	The end grafts are then glued in. These are made up from two outside flanks of bwb purfling/curly eucalyptus (which will be the binding) with a central strip of Old Rio Rosewood. The graft on the left is a dry fit test and the one on the right has been glued with fish glue and taped down.
	Here's the rim after scraping down the end-grafts.
	The sides have been tapered on the bottom of the hollow necks.
	Here's the rim set in the mold.
	Next the khaya back and top pieces are thicknessed for joining. I finish them using a cabinet scraper.
	The top and back sets are routed for joining using this jig.
	The tops/backs are joined using the tenting method using hot hide glue.
	As the pieces are thin I need to clamp them in this jig while the glue sets up.
	The joined top and back are cut to rough shape and then the rosette channel is routed out on the top.
	The rosette is inlaid and glued in with white pva glue. The rosette strips are not joined at the top but under where the bass side fingerboard will be.
	When the glue has dried the rosette is scraped down flat.
	The soundhole re-enforcement patch is then glued on using fish glue.
	The soundhole is then cut.
	Next the spruce bridgeplate is made and glued in using hot hide glue.
	Hardwood inserts are glued into routed slots in the bridge-plate where the bridge-pins will go.
	The main ladder braces are now glued in starting with the lower bridge-plate brace. the bottom of the braces are shaped to a 13' radius and they are glued in with hot hide glue.
	Next in is the upper bridge plate brace . . .
	. . . followed by the lower soundhole brace and A frame braces.
	The upper soundhole brace is notched to fit over the A frame braces and then glued on.
	Here's the top with the bracing completed but not yet profiled.
	Now for the back. The X braces are profiled to a 10' radius and notched. The first one is glued on with hot hide glue.
	Then the second back X brace goes on.
	I need to make the fingerboards to ensure that the necks align. They are sycamore and have been marked for frets and tapered. This jis is used to route the slots for the fret markers.
	Here are the slotted boards. The bottom one has the markers glued in.
	The boards are cut to final shape and then bound with curly eucalyptus to match the main body binding. The lower board has the binding glued on.
	Here are the two bound fingerboards.
	The top of the rim-set is shaped to fit the top and the Spanish cedar linings glued on.
	The top is cut to fit the rim-set and tried for fit to the rim-set - I haven't carved the top braces yet.
	The X braces have been capped with a piece of curly eucalyptus and the braces profiled. The bottom ladder brace for the back has been radiused and notched to fit over the X braces. It is then glued on with hot hide glue.
	The second ladder brace is then glued on.
	The rim-set is shaped to accept the back and the back cut to shape. Then the linings for the back are glued on.
	The back is then glued on using fish glue.
	Spruce side braces are inlet into the linings and glued on, the carbon fibre flying buttress braces are glued in and the carbon fibre neck "lattice" is completed. The centre seam of Cuban mahogany has also been glued on.
	Then the top braces are carved and the top "voiced".
	When I am happy with the top I date and sign it - given this guitar's name there was no other motto. It's also a Rick Mayall/Blackadder joke that Martha will appreciate.
	The box is ready to be closed . . .
	. . . and it is glued up using fish glue.
	Brazilan Rosewood position marker dots have been made and inlaid into the fretboards. Two wooden dowels are inset below the first and last marker and holes drilled in the hollow necks so that the fingerboards locate properly. This will help when the fingerboards are glued on after the body has had finish applied.
	The curly eucalyptus binding have bwb side purfling glued to them and are then bent in the Fox-bender.
	The binding channels are then routed . . .
	. . . and the binding and purflings glued in with fish glue.
	Now onto the bridge. The sycamore blank has the saddle slots routed . . .
	. . . and then the pin holes are marked, drilled and countersunk.
	The bindings have been scraped back and sanded, the bottom of the bridge has been shaped to match the top's curvature and the two outer bridge pin holes drilled through to hold the bridge on when it is glued on.
	Z-Poxy has been applied as a grain filler and then the body sprayed with pre-catalysed lacquer. This is allowed to cure, flattened and hand-rubbed with 0000 wire wool. The fingerboards have also been sprayed and are then glued down using fish glue.
	The bridge is glued on with fish glue , , ,
	. . . then after lots of setting up here he is.
	And here's a happy Martha. You can here a sound clip here.