Lute Progress -

[kiwigeo]

Ok Ive finished cutting two of the test rosettes and the consensus is that the mini chisels are the go. The chisels allow me to do each cut in one go where as the scalpel often requires a couple of goes to get the blade right through the top and the paper each side. The scalpel blades have a bit of flex in them while the chisel is rigid. Im also able to get a more square cut with the chisels by using the reflection of the pattern on the back of the chisel blade. I have a number 5 mini gouge which is making cutting of the tighter curves alot easier than with the scalpels. Another trick Ive learned is to go around the pattern lightly with the chisel first, just breaking the surface of the top and then going around again doing the final cuts.

[kiwigeo]

Rough cutting of two of the test rosettes is finished and Ive removed the paper pattern by covering it with wet tissue and applying a warm iron on top of same. Results aren't too bad with a little bit of clean up required and 2 splits to be glued up on one of the rosettes. Something Ive discovered is that the pattern Ive used isnt that accurate and although from a distance the rosettes look ok, close up there are noticeable discrepancies in places. Before I do the real thing I'm going to have to redraw the pattern and make up a new master.

[kiwigeo]

Pictured are the microchisels Ive found are the best for cutting the rosettes above. On the left a number 5 gouge and to the right a selection of straight chisels. What I think Ill do with the straight chisels is reduce the bevel to around 10 degrees to reduce risk of splitting the top along the grain while pushing the chisel into the wood.

[Nick]

Who's a clever bugger then?
Nice job Martin, even with any 'discrepencies', I'd say you'd been doing that (cutting rosettes) for a while if I didn't know any better.
And yes, I've often thought that of chisels, that they work on essentially driving a sharp wedge into the wood, it must upset the fibres on the top edge of the cut. For the soft wood I'd be doing the same as you & reducing the angle, the edge doesn't need quite so much support.

[PHANTOM]

Nice work mate those chisels look like a nice bit of gear too.

[kiwigeo]

And yes, I've often thought that of chisels, that they work on essentially driving a sharp wedge into the wood, it must upset the fibres on the top edge of the cut. For the soft wood I'd be doing the same as you & reducing the angle, the edge doesn't need quite so much support.

One trick Ive picked up to minimise splitting around the periphery of the area that will be void is to chisel a cut into the piece thats going to come out (the chit)......the cut within the chit will tend to take up the movement of the wood fibres rather than the wood that will stay splitting along its grain.

Something else Ive noticed is that alot of the cut out holes in the rosettes have bevelled edges.....this is obviously from the chisel pushing into the fibres before the blade starts cutting. Its worse on the second rosette so obviously the chisels were starting to dull a bit.

[J.F. Custom]

LOL I notice the pdf has been downloaded by two users already...ok WHO are they!!!!

I have to put my hand up as number two on that list... but I don't know who beat me to it! I stash away useful bits of info like this when they present themselves. I've also got Mr Lundbergs tome with the intention of making one sometime. Sometime being the operative word. I see the quota is at 19 now

It was actually the bowl back mandolins that caught my initial interest and the construction of the shell. I've a very nice old Washburn c1900 Mando in Brazilian and Honduran from my grandfather. They did three models at the time to the best of my knowledge - The basic (no ornamentation); professional (binding and minor inlay work); and the deluxe which was covered in bling and much too much for my taste. There is not a lot of info out there and certainly nothing on serial numbers as their factory burnt down (twice?) and all records were lost. I've got the professional unit and it is in remarkable condition for its age with only a minor crack in the soundboard to repair; although some of the old binding is fragile as they do get and the tuners are buggered and need replacing. Unfortunately, they had a different post hole spacing at the time to modern tuners so I'm in a pickle. Haven't located any replacements that would work, but did not really want to plug and re-drill the holes either - to keep it original...

Something else Ive noticed is that alot of the cut out holes in the rosettes have bevelled edges.....this is obviously from the chisel pushing into the fibres before the blade starts cutting. Its worse on the second rosette so obviously the chisels were starting to dull a bit.

Could you 'score' the pattern lightly with a scalpel first, then 'cut' with your chisels? Or is it not of a concern anyway - aside from sharpening your chisels?

Nice work btw.

Jeremy.

[matthew]

Martin looking good. Are you going to "weave" the pattern? That'll make any discrepancies much less easy to spot, as if they are now!

[kiwigeo]

Martin looking good. Are you going to "weave" the pattern? That'll make any discrepancies much less easy to spot, as if they are now!

Yep that's next.....and then...wait...... there's more!!! There are flutes to be carved along the interweaving sections of the rosette.

[charangohabsburg]

Hi Martin, it's simply amazing what you're doing here!

Now I finally understand why the Vihuela in Paris (Museum Jacquemart-André) has so many soundholes: someone must have been practicing rosette cutting- and inlay techniques and did not want to cut out the individual rosettes to hang them on the Christmas tree...

[sebastiaan56]

Noice Martin, where are the chisels from? They look like a bitsa set which isnt normally your style.

[hijack] Jeremy, have you tried David Hynds? http://www.mandolinluthier.com/ Great resource for parts and repair information. Good guy as well.[/hijack]

[Puff]

Martin - might it work to drill out some of the waste in the chits prior to chiselling. Could relieve some of the tendency for splitting and bevelling?

[kiwigeo]

Martin - might it work to drill out some of the waste in the chits prior to chiselling. Could relieve some of the tendency for splitting and bevelling?

Good idea..thanks for that.

[kiwigeo]

Noice Martin, where are the chisels from? They look like a bitsa set which isnt normally your style.

They're a combination on Pfeils and two Cherries chisels. Got them from Toolsforwoodworking and Dicks.

[duh Padma]

Now theres something you don't see every day.
Me hat goes of to you for pulling it off and posting it for our eyeballs.

blessings
duh Padma

[kiwigeo]

Now theres something you don't see every day.
Me hat goes of to you for pulling it off and posting it for our eyeballs.

blessings
duh Padma

Thanks for the compliments oh great robed one

No comparison to the exquisite chisel work on the furniture in your workshop though....always good to have something to aspire to.

[duh Padma]

Now theres something you don't see every day.
Me hat goes of to you for pulling it off and posting it for our eyeballs.

blessings
duh Padma

Thanks for the compliments oh great robed one

No comparison to the exquisite chisel work on the furniture in your workshop though....always good to have something to aspire to.

Aw shucks kiwigeo,

but lets not bull shit a bull shitter. The butchery me did in me shop is just that, butchery compared to the single point focus required for what you just pulled off. And everybody on here knows that and if they don't, then they don't know diddle squat.

And you can tell em me said so.

blessing
duh Padma

[kiwigeo]

Ok, this is turning into a major exercise. Ive finished punching out 3 of the test rosettes but Im still not happy with the quality of the process....probably more my anal approach to guitar building coming out more than a genuine problem actually existing but thats the way I work.

I halted operations on Saturday and spent half a day searching the net for anything I could find on cutting lute rosettes. What I discovered was that a significant number of people make up their own cutting tools rather than use commercially available chisels and knives. So yesterday was spent starting work on a set of home made mini chisels and knives. A set of hacksaw blades shave been stripped of paint (soaked in acetone) and at the moment the steel is being polished up on a diamond stone ready for shaping and sharpening. A set of wooden handles will also be made up. Will post up pics at the end of the process. Last night I got impatient and finished up a prototype 3mm mini chisel and gave it a test on some spruce....perfect cut straight through the wood and into the cutting matt underneath. No fuzz..no crushing of the spruce.

Right....I'm off to see my pshyciatrist. Everywhere I look I'm seeing lute rosettes

[sebastiaan56]

He's taken the Red Pill folks.....

[duh Padma]

Right....I'm off to see my pshyciatrist. Everywhere I look I'm seeing lute rosettes

NO DO NOT go see the shrinks.

You on the verge of the BIG break through. In fact its already happening...you making your own tools to do just what you need...This magic can only come from inside...knowing what you need and then doing it.

Go take some more of the red pills, look at crop circles, childrens spinning tops, any thing that goes round but for gosh sake ...don't go to the shrinks.

I did...worst mistake in me life...took me years to get their B.S. games out of me head, sobber up and fly straight again.


blessings
duh Padma

[Clancy]

Everywhere I look I'm seeing lute rosettes

Everywhere I look I'm seeing Oprah.

Admiring the work, the tools and awaiting a pic of the tools to come.
Onya mate.

[P Bill]

Fine work on a very lively bit of geometry. It'll really start to snap with the weave.

[P Bill]

I mean visual snap.

[kiwigeo]

Not alot of progress on the homemade chisels due to the return of the stinking cold I had last week. Ive made up 5 blades and handles and have got to the stage of final honing of the back of the blades.

[duh Padma]

Don't know if this will help but me just remembered...

Spring steel. Comes in all sorts of thicknesses, widths and grades...however me made a few Blades from the black spring steel strapping that you find in the garbage bins at lumberyards.
It holds an edge for a reasonable while. and there is just something about a blade with some spring to it. Beats breaking all them # 11 scalpels. Then me got some really good stuff the my son uses for the springs on the tattoo guns he manufactures...real good spring to the blade..ok for holding an edge too.

blessings