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I mentioned in another thread about a tool I was given that belonged to a old man. He passed it on before he died to a friend and he gave it to me. Made in Germany is all I can see on it. One thing that puzzles me is the cutters, the way they are ground. Like a dimond shape. I would think you would want a flat on one side of the knife to cut a nice square side to the channel. Seems as if the diamond shape will cut a slightly angled side making a gap between the sound board and the rosette.
??
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Cut to size.....Beat to fit.....Paint to match.

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No I am not sure that is it's intended purpose. If I decide to use it I will make new cutters.
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Cut to size.....Beat to fit.....Paint to match.

I have something very much like it that my grandfather used to cut holes in cabinets for plumbing. I will tell you that due to the ease in tilting it is not very accurate for rosette work. Variance in the tilt as you turn it increases or decreases the working center from the point of rotation. It would work just fine if it is sharp and there was a way to insure a pure vertical plane while using.

I am sure in the past century this was exactly what was used and it still will work to day if pure geometry is not critical to the rosette you are inlaying. For individual purfling inlays it would work fine great but for pre-fab wood and shell inlays you might have an issue with concentricity.

That could be avoided if you could attach a washer like gizmo on the center, to keep it level as you cut.

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Waddy

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Sound Clips of most of my guitars

Neat!!
That baby is old !
Maybe it was used to scribe circles .
Hence the diamond shape.
Even if you never use it -it's a treasure from the past!
Is the machining work of good quality?

Mike

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Mike Collins

Michael,
I have messed with it and it is not that hard to keep plum. If the second cutter is set for the inside of the ring and because it is on the opposite side of the bar from the first cutter it tends keep things plum. I don't think eccentricity is a issue. It is a hand tool and as such does require some skill and finesse. I think the cutters are not ground properly to do the best job though. If I had more time I might mess with it but I have a long list and this is waaaaaaaaay down there. I don't intend to use it unless the grid goes down. It is a faily complex little tool though and kind of interesting.
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Mike,
Yes it is machined nicely. And yes it goes up on the mantel with the Stanley # 1 and a few other cool tools.
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Cut to size.....Beat to fit.....Paint to match.

In his article on making traditional rosettes in 'American Lutherie', Eugene Clark mentions that he uses a double bevel on his rosette cutter. It does make a 'V' shaped cut, but he says that once the glue hits it the wood swells back and closes up any gap. From the pics in the article I'd say he knows what he's talking about. Naturally, you want the cutters to be super sharp....

Alan,
Thanks. That's the difference between theory and real experience. I thought that it might work that way especially sense your not making a very deep cut. The ridge or spine on the <> shape might push the wood and still make a realitively square channel and then as you said the glue will swell the wood back. Might be easier to make a tight fit with this ! Still going with the router though.
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Cut to size.....Beat to fit.....Paint to match.