Welcome all to another build thread. I haven't had a chance to build anything new yet this year. Luckily that has now changed.
I started building an OM, a new shape for me, last week. Its an OM shape i have come up with myself, and hopefully it looks nice at the end, I quite like the shape in my mould anyway, thats a good start!!
After the recent thread from Mark Hatcher talking about Redwood for tops, seeing as using Redwood was something I had been thinking about, it convinced me to go that direction this time and I managed to acquire a Redwood top from a supplier he knows. Its one of the Oregon "tunnel redwood" tops, cut from the support beam of a tunnel build in I think 1880, meaning the wood was cut about 150 years ago!! Its a beautiful piece of wood and has a very bell like ring to it, i'm very impressed with it and as long I don't make a hash of the build i'm optimistic its going to be a good one.
The Leopardwood came from a local classical builder who has had it for a long time but has never had a customer interested in it and hasn't had a chance to work with it, I thought it looked pretty awesome so I decided to take it off his hands. It has turned out to be very very tricky to bend but more on that shortly.
The neck will be a 5 piece flame maple/mahogany/maple/mahogany/flame maple block from which I will hopefully get 2 necks from. I much prefer one piece necks (ie no stacked heel, its too hard to hide the join) so this is the direction i'm going in to allow myself to do that.
So to the building of the guitar itself, after first deciding I wanted a different shape, I decided that I would go in an OM direction. Several hours in CAD later a shape I liked emerged on my screen. I then had it plotted full size onto A1 paper and having recently met someone with a CNC contact, i utilised him to make my new mould. I now think my mould might be a little narrow/low at 60mm, but not a lot i can do about that at the moment. I guess i'll just see how it goes.
Another new thing this guitar will be incorporating will be a bolt on neck. I'm 95% sure how I will be doing that, its the extension bit that incorporates the vertical bolts i'm not sure how to rout accurately yet, thats not to be done for a while though, I still have time to work that out.
In March I was in California and met up with Kevin Ryan, he mentioned his process of deflection testing every top and now can see on a spreadsheet graph years later which values worked best and what to aim for. Kevin along with several other builders I have met and talked to recently, several of whom were at the Holy Grail Guitar show such as Peggy White, encouraged me to do the same. I built a deflection testing jig and tested my top. For that I thicknessed the top to 3mm and tested with the weight directly in the centre of the board. Because the workshop I go to only has very large bandsaws and its difficult to get an accurate cutout a constant amount outside the template outline, i decided to test the board only after being joined and thicknessed to a what will be 'standard' for testing purposes 3mm.
Obviously the results that came out mean nothing for this guitar, nor for anybody else, but hopefully several down the line i'll have a my own chart and will know what i'm doing right and/or wrong.
I have now cut out the top and back to approximate guitar shapes and that process makes it all seem more like i'm building an actual guitar now!
I followed that up by bending the sides. The Leopardwood is a mission to bend. Its very hard, very dense and very resinous. It took nearly 3 hours maybe more per side to bend, it was weird, at no point did I feel the wood 'submit' and allow itself to be bent easily, I got there in the end, but that wasn't fun. I don't think they were too thick, they were the same 2mm i've used in the past.
Now the obligatory pictures. Enjoy.
My new OM mould shape
Untitled by
David Emm, on Flickr
The Redwood top in the deflection testing jig. Temporarily using my mahogany neck block as a zero block for the micrometer and without the actual weight applied to the jig yet.
Untitled by
David Emm, on Flickr
My tasty Redwood top
Untitled by
David Emm, on Flickr
The Leopardwood back
Untitled by
David Emm, on Flickr
Leopardwood sides being bent
Untitled by
David Emm, on Flickr
One of the bent Leopardwood sides, will probably need quite a bit of sanding to get rid of the resin that has come out from the heat.
Untitled by
David Emm, on Flickr