Goings on in the shop

[kiwigeo]

With the oil patch going through a "quiet time" Ive had a bit more time than usual in the workshop. This weeks efforts have been concentrated on a parlour guitar I started some time ago. Pics of the rosette going in. I opted for a herringbone rosette pretty much as per the Scott Antes plan Im using as a guide.

[Kamusur]

The Carruth scraper looks like its doing a great job Martin, but i dont recognise the circle cutter thouigh. Very nice clean and tidy work.

Steve

[kiwigeo]

The circle cutter is a router job I picked up years ago. Ive tried Dremels and manual cutters for doing rosettes but I always seem to go back to my trusty Trend T5 and the circle cutter. I was using standard two flute cutters but this time around I used down cut spiral cutters with a brass adapter to mount the 1/8" diameter cutters in the routers 1/4" collett. The cutters performed well.

[kiwigeo]

Working on the falcate braces....Im using King Billy Pine. The stuff bends like butter and I like the colour contrast against a spruce top. Glue Im using is techniglue epoxy.

[auscab]

Nice one Martin .

You got the big tins of techniglue I see , at guitar building rate you should be about half way through them when your about 80 or 85

Rob

[kiwigeo]

Nice one Martin .

You got the big tins of techniglue I see , at guitar building rate you should be about half way through them when your about 80 or 85

Rob

The big tin is the resin....the hardener tin is half size. These are the smallest tins Carbatec have.

Ive actually got 3 guitars on the bench at present....a Classical (95% finished), the Parlour and the Gore OM.

[auscab]

Three at once ! Great .

Ive seen smaller tins some where in my travels , somewhere ? Not that it matters , a much better price per gram buying it like you have .
I use the same size tins on the furniture and it takes a year and a half to get through them at that size . I just do important lamination's and gappy old furniture repairs with it. and that's with two or three guys using it as well at times. I find the hardener tends to go off a bit as it gets near the end . it could be contamination with the resin , not sure ?

A neat way of separating it for storage into smaller amounts would be good, even for the rate I use it at.
Small Milo tins maybe ?

I used to use large tins of 24 hour Araldite before I got onto the Techniglue, that seemed to set with a little more flex. Thecniglue is harder and more brittle .

I was trying to cast a handle for a machine with it a few months back. I failed at the mold making stage though.
I have to buy the right mold making silicon product for that.

Rob

[MattW]

Rosettes looking good!

Paint shops will have small new empty paint tins in various sizes up from about 100mL or 250mL. I got a 500mL one recently for around $3.

[kiwigeo]

Today I decided to start a repair/modification job on a Kora thats been sitting in my shop for 5 years now. The instrument has 5 strings which are actually strands from a bicycle bike cable. Originally the strings are tied to bits of rag which are then wrapped around the cross piece. The owner wanted these replaced with tuners. The cross piece wasn't strong enough to take the banjo tuners so I cut the rod in half and then reassembled it with a resin soaked CF sandwich in the middle. Next job will be filing the cross piece to 11mm thickness and then drilling 9.5m holes to take the tuners.

[kiwigeo]

More pics of the Kora modifications. Got the cross bar shaped and bored and banjo tuners fitted. I opted to put the original bicycle brake cable strings back on pending arrival of some 0.014" Ernie Balls. Ive also added a crude saddle which improved the sound of the instrument markedly. Theres one more tuner to go on....yesterday I discovered the broken remains of a fifth string so an extra tuner is on order.

[Kamusur]

That's an interesting fix Martin.

Steve

[kiwigeo]

This instrument has got me intrigued having had a chance to have a close look at it. The owner told me its a Kora but after a bit of goggling Im inclined to think its actually a Sudanese instrument called a Rababah.

https://www.youtube.com/watch?v=p79FZ7IxVoc

[scripsit]

Martin

It's more likely an Ethiopean Krar Harp

https://www.youtube.com/watch?v=8tO7lD-BWTU

Kym

[kiwigeo]

Martin

It's more likely an Ethiopean Krar Harp

https://www.youtube.com/watch?v=8tO7lD-BWTU

Kym

Possibly Kym but the owner is Sudanese. The guy will be coming around to pickup the strange instrument so Ill ask him then what it is.

[Dave M]

Martin that African instrument looks like real fun. I love the idea of strengthening the crossbar with our high tech methods so as to take tuners. It will be much nicer for the player. I have been amazed at the musicality that can be coaxed from these apparently primitive instruments. The Kora is quite sophisticated with many strings and a somewhat harp like playing position using both hands.

Anyway you wondered what was happening in the workshop...

As a completely amateur maker I have been enjoying the carving of the neck on build number 2 (the first didn't count). I have actually made rather more necks than guitars for various reasons...

It is a bit nerve racking since a mistake would be difficult to fix. But enormously satisfying. I just love ending up with this gorgeous shape. I think the classical heel is a very beautiful thing. As a player I am also very aware that this shape is an intimate part of the experience of playing and so needs to be just right.

It also I guess signifies the fact that I will be spraying soon and getting some strings on to see how it sounds.

Dave

[kiwigeo]

I wouldnt get too worried about a few failed necks.......I have a wall of shame hanging above my window.....5 necks with various gaffs and stuff ups. Whenever Im working on a neck the wall of shame is there to remind me not to make the same gaff(s) again.

[kiwigeo]

More work on the Parlour today. Braces glued in and shaped. Just a bit of tow to lay on the main braces and the sound hole reinforcement and then in with the UTB and the top is basically done.

[kiwigeo]

Top finally finished and ready for test fitting.

[kiwigeo]

Got the box closed up and did some initial tap testing. Results below. For tap testing Im using a Shure SM57 mic, a pre-amp to boost signal and VA running on my cheap little HP laptop. Peaks are verified using tap test function on Peterson Stobosoft.

Helmholtz T (1,1)1 - 121Hz
Main Top T(1,1,)2 - 213Hz
Main Back T(1,1)3 - 264Hz

[luke_lee]

Hi Martin,
Did you have a target frequency combination in mind? What's the diameter of the soundhole?
Thanks Luke

[kiwigeo]

Hi Martin,
Did you have a target frequency combination in mind? What's the diameter of the soundhole?
Thanks Luke

Hi Luke,

A good question....I thinned the periphery of the lower bout and got Helmholtz and main top peaks down by a few Hz. Im currently doing a bit of research on other parlour builds here on the forum and via Google. I notice you made effective use of a Tornavoz on one of your builds and got the frequencies down to close to that of a classical guitar. At the moment my guitar seems to have frequencies in the vicinity of what Jim got on his recent build.

Unfortunately the top I used was a jointed top I acquired along with a stack of neck wood from a local builder here in SA. The top appears to be Sitka.

Soundhole diameter is around 83mm from memory....most of the measurements for the instrument are off a Scott Antes parlour plan.