Back to work

It's been ages since I had any time for instrument making. I've started a new job, been refurbishing a flat, we've got a new puppy and I've been trying to fix the leak in the d**ned shower. But finally, I've got started on the pegs: The third one from the left has been finished off and I'm using it as my template - the rest are fresh off the lathe. I need thirteen, so I will make about twenty and choose the better ones.

Pushing on with lute

I'm still making slow, but steady progress with the lute. Here is the peghead, made from beech wood, together with my first practice peg. This one was made from cherry, but the real ones will be turned from pear wood. I think I will make the collar on the peg a bit simpler, and make the 'pip' (the tiny button on the end of the peg) a bit rounder.

Back to the lute

I'm back to working on the lute now. I have fitted the counter-cap to the inside of the bowl (it has a much better shape now), and I've glued on the bridge (with hide glue, of course). I now have to do a bit of tap tuning by shaving away some of the braces on the underside of the belly (although this will, as usual be more luck than judgement!).

I also have to glue some paper reinforcing strips along the rib seams on the inside of the bowl.

Arching (part two)

Starting...

 Here are the results from my first practice run with the overhead pin router. I started with a piece of walnut, fixed with double-sided tape to the holding table. I started the routing with the uppermost contour and proceeded to go deeper each round.

It was pretty straightforward, and reasonably quick. There were a couple of issues to fix, though. First, I need to find a better way to remove the chippings as they tended to find their way under the holding board, giving its movement a 'gritty' feel. Perhaps the answer will be to cut some slots in the table itself and figure out a way of connecting these to my dust extractor.

The second issue was setting the depth of the router cutter, which was a bit fiddly. I think that a threaded rod fitted to the router (one turn per mm) might work, or if I'm feeling extravagant, a digital depth gauge.

...part way through...

I will finish off the back sometime soon and who knows, perhaps a walnut F5 mandolin will form around it!

...all the contours cut

Arching (part one)

I was thinking about making archtop backs and bellies a while back and I came across an arching pattern from Andrew Mowry's website. This set me to pondering on the best way to do the initial carving on one of these and I decided it called for an overhead pin router. Having previously made the front for a Les Paul guitar, I know how much work is involved and how difficult I found it.

I sketched out my design in Google Sketchup and put it together from bits I had round the workshop (except for the rubber castors which I bought online).

Pin height adjuster

The router height above the table is set using its 'plunge' and the pin height is set with a modified lever-operated clamp mounted underneath the table. The routing table can be adjusted up or down by 10cm if needed as it's fastened with bolts and wing nuts running in vertical slots. .

The real thing...was not quite so neat!
The router is mounted one third of the way across the width of the table to allow wider pieces to be worked on. I also added a safety STOP switch and a box for the spare pins etc.

Underside of the holding board

The wood to be carved (in this case a back) will be stuck into place onto the top of the holding board with double-sided tape and the template (in fact a mirror image) is mounted on the underside with fixing bolts. The template set corresponds to each of the contours on Andrew Mowry's plan. In order to engage with the pin properly each plywood contour was 5mm deep. I found that four of these could be stacked and glued together for convenience.

The idea will be to start with the pin fully retracted and take the thickness down to 17mm. Then the pin is raised by 5mm, and the router cutter is lowered to 16mm and the first contour is cut. Then the cutter goes down to 15mm and the pin up another 5mm and cut again...and so on.

Now to see if the theory works out in practice!

Arching Template sets

The Tenor Uke is finished!

The tenor uke had its strings fitted today - a set of nylgut ones from Aquila. They seem to take ages to stop stretching and to stay in tune, but I have read to expect this. It's certainly different from the usual mandolin wire.

As usual, there have been a few 'compromises' along  the way. The strings didn't quite align properly at the bridge (I think the hole was a millimeter or so out)  but I was able to adjust this by making grooves in the saddle. The kerfed lining, visible through the soundhole looks a little slapdash as I cut it by eye - next time I will have to make a jig to to this. Also I still haven't reached a satisfactory standard with the finish - I'm wondering about investing in a set of buffing wheels for my drill press.

The binding has worked really nicely, although quite a few bits snapped when bending them to the tight curves on the ukulele. With the binding around the heel I actually had to laminate in situ, as there was no way to bend binding to such a small radius.

The instrument is fairly loud and bright (which was the tone I was hoping for) and as the actions has been left quite high (3mm at the 12th fret) it's can be played 'robustly'. Here is a quick soundfile.

Overall, I think I have done a good job, and once again I have learnt a lot. I will buy a quirky gig bag for it and hope that it goes down well at birthday time.

Starting to finish

I'm now adding some coats of Tru-oil to the tenor uke. I have already made the bridge, so there's not too much left to do now. I'm confident that I will get it finished before the relevant birthday!

After it's done I will be getting back to the lute and the mandocello.

Binding

Here are the binding channels cut into the front of the tenor uke. I used a small router and the set of special cutters that I bought from Stew Mac ages ago.

Both the binding and the purfling (made a similar way) were bent to shape on the hot iron (with a few breakages!) and glued in.

The first side I fitted the binding and left a channel for the purfling to fit later, but this was a bit messy. So, for the other half I fitted both together.

After scraping it down I think it looks quite smart

Woodworm

I have been working on the neck of the tenor uke (the 'mystery' instrument). All was going well until I discovered that the sycamore was full of woodworm flight holes. First, I tried to patch these by drilling out the holes and filling with sections of wooden toothpicks. And then I thought...what am I doing? Do I really want to make a neck out of timber full of holes?  No.

So, it was back to a new piece of sycamore and start again.  The second photo shows the new neck clamped up, next to the wormy old one (which is destined for the rubbish pile!).

A bit more work on the 'mystery instrument'.

I have done a little more on the 'mystery instrument' this weekend (it shouldn't be too hard to guess what it is!). The sides (and back) are cherry, which was quite nice to bend. I used to soak wood before bending it, but since working on the bowlback mandolin, I have discovered that this is not necessary (unless it's really thick).

The form is made from pieces of 1" plywood glued together. This is quite expensive to buy new, but I discovered a nearby social enterprise called Chiltern Wood Recycling, that sells ideal materials for this sort of use.

Lute Bridge

I've been making a bridge for the lute. It turns out that these are quite complicated affairs - deeper and fatter at the bass side, with some fiddly 'scrolls' and undercuts. While it's being made, the bridge is best supported in a special jig which I had to make first. I scratched my head over how to make the right profile for the jig (I certainly don't have any router bits that would fit the bill) and then I remembered the trenching plane that used to belong to my Dad, and before this my Grandfather! It did a great job - who needs electric routers!

The bridge can now be glued to the belly (with hide glue) prior to tap tuning.

Cittern Ready for Shipping

Here is the cittern ready for shipping in its custom crate. Fingers crossed that no one drives a forklift over it!

Cittern Soundfile

Here is quick recording of the cittern. All the courses from open to the 21st fret, followed by a bit of messing about - my playing skills do leave a lot to be desired!

A Mystery Instrument

I've had some interest in my Cittern, so I tuned it up to pitch to check it over. The bottom course was a bit 'growly', and I have found that the action is a little too low, so I have made a start on fixing this by adjusting the bridge feet a bit. Everything else seems in good order so I just need to find a good way to ship it safely, and to confirm that the potential new owner is willing to go ahead.

All the bars on the lute are now glued in place and I have made a start at trimming them to exact length. On the lute they play an important role in the structure of the whole instrument (which doesn't have any lining) as well as the tone, so this has got to be accurate.

Finally, I have started work on a mystery instrument. I can't reveal what it is because it will be a present for someone, but so far I have prepared some cherry wood for the back and sides, and made the belly. Here is a photo of pieces for the rosette inlay in preparation on a template I turned on my lathe.

Inexpensive Bindings

A while ago I bought some binding from Stew Mac. I was really happy with the results, but I thought it was an expensive option at £3.60 a meter (plus shipping and tax!) so I decided to make some of my own. I started by preparing a piece of sycamore about 60cm long by 5cm by 0.5cm. I cut a couple of bits of black stained veneer and one of unstained sycamore (5cm by 60 cm) and laminated a sandwich using Titebond glue. When the glue had set I planed one edge true and then used a small bandsaw to slice off 3mm . I then planed the newly sawed edge of the 'sandwich'  true again and bandsawed off another slice. In the end I had a pile of bindings each with one good face and one rough sawn one. These went through the drum sander to finish them down to 2mm thick and ...voila!

The bars

I have now started gluing on the bars. These add strength to the belly (which is less than 2mm thick) but also allow it to be 'tuned'. By reducing the thickness and shape of the bars, the stiffness of particular parts of the belly can be changed which will alter the tone and loudness of the instrument. There isn't room to clamp these all at once, so I am doing them a few at a time. I found that putting a small piece of veneer under the middle of the caul (the bit of wood that spreads the clamping pressure) I could get the middle of the bar to stick down properly (I could see the glue squeeze out). You can also see in the photo (most of) the rosette template which I decided not to remove, as I thought it would strengthen the delicate wood a bit.

I took the  dimensions for the bars from the plans, and they looked tall and narrow, compared to what I was expecting. I recently read an interesting article  written by David Hurd (of left-brained lutherie fame) and it seems that the stiffness of a bar is directly proportional to its width, but proportional to the cube of the height. So tall thin bars can be stiff without being too heavy (which would dampen the resonance of the belly).

Rosette

I joined the two halves of the belly and thicknessed it down to about 1.8mm. The area for the rosette was then scraped down from the inside to a thickness of around 1mm. The photo shows the lute rosette after the initial cutting out. The paper pattern was glued to the inside and the fragments were cut out with a scalpel. The next step will be to carve the relief (to give an intertwined appearance) and to chip carve a ring around the outside. Once all this is done I can mark out the final size of the belly and get on with finishing the bowl!