An Improved Rosette Cutter

Much earlier in the year when I was down at Micheal Connor's place in N.S.W. preparing kits for our ukulele class, we got to discussing rosette cutters and how everything out there was made for guitars and just didn't work for ukuleles without some sort of modification. And even then they all left something to be desired. So as you do after making shavings and dust after a long day, we had a cold beer and started to put pencil to paper and see if something better could be made.

Micheal has a really well fitted out wood and metal working shop, so after some sketches we were off to the metal lathe and started on some prototypes. There were quite a few variations and improvements to the tool over the past months, with testing and feedback by some luthier mates, the 2012 Cairns Uke building class, and even Robbie O'Brien has one in his tool box.

What sets this tool apart from any that we've been able see is that for one it's sized so that you can cut a sound-hole / rosette as small as 28mm in diameter and out to 210mm maximum. Then with the addition of 2 routing blades you are able to cut and install the compete rosette without any power tools at all. I've seen so many posts from hobby builders working on the kitchen table in an apartment about only being able to use hand tools. Well this solves that problem no worries.

He's also use the same 3/16" pin that StewMac and similar devices uses for there router base, so if like me you have a need for a very fine purfling line in the 0.6mm range as part of your inlay, then you can use your router base and appropriate bit as well if you like. But, the tool is complete as is, and there is no need for the power tool option. It's just there if you like.

Made from Brass with HSS blades that are supplied extremely sharp. More than ready to go right out of the box. The tool is 6" long overall and has great heft due to the brass. Makes for a very solid feel in use. Just like a professionally made tool should be.

Here is an image of what's in the box. The wooden blocks are used for setting the depth of cut on the blades. Each step is 0.5mm.



Micheal has a limited number available for purchase on his website.

Looks like a nice rosette cutter- I like the bearing as a roller.

I tried to use a sloped shooting board like the one for sale on his site but found it harder to use then a flat one. Perhaps my plane sole + blade weren't perfectly aligned.

The bearing is integral to the depth control of the cutters, and it really does make rolling the cutter around so much easier. The thumb wheel that you use to tighten up the dovetail slide that adjusts the diameter of cut has a small step it it so that there is just a small contact area around the pivot pin to minimise friction as well. This keeps the entire body of the cutter up off your top.

As for shooting boards, I use a flat one as well. Never tried the ramped one, but I know plenty that swear by them.

Last year I made a scaled down (to uke size)version of the LMI rosette cutter for PH... I think this one from Mr Connor is a lot better design.:agree:

**Edit***.... I found the thread here.
http://www.ukuleleunderground.com/f...osette-Circle-Cutter&highlight=rosette+cutter

Nice job looks great

Mine works gr8 Ken - thanks much....

Actually, I had seen yours Ken, and some comments on that thread got me to thinking about ukes and guitars.

Our initial designs were much more complicated, and while they worked great they took far too long to make. Way too many parts and machining operations. So lots of revisions and trial and error. But more than anything it was trying to work out the blade shape and geometry to get them to cut cleanly in both directions, and route out the waste that was the tricky part. Those blades are just so small, and expecting someone to be able to put an edge on them at home wasn't reasonable.

So after trying various methods that didn't meet our expectations, Micheal bought a Russian made universal tool grinder for a pittance as everyone has gone to CNC now. There isn't anything that this grinder can't shape or sharpen, and made all the difference in accurate and very sharp blades.

I use a turntable and milling machine for rosette work...I can't see me using anything else...it works for me

Thanks to Allen, who helped me, and to Micheal who made this tool, I now have that wonderful feeling of fulfilment that only a new tool can give. No doubt a turntable and a millimg machine is good, but this is something you have to hold to really understand.

Micheal even made a special cutter for me for thin rosettes. So there goes my excuse for not making any!

Some pics, and roughly the same info:
http://www.argapa.blogspot.se/2013/01/new-rosette-soundhole-cutter.html

Looking good Sven.

The original set of cutters were for what we thought would be common scenarios for rosettes include 3 cutters.

One slicing blade that has flat on one side. You reverse it depending on what side of the inlay you are doing. The flat is to the side you want to keep square. Then there is a 5mm wide routing blade and a 0.030 chipper that would do typical b/w/b purfling channels.

When Micheal told me that Sven had ordered one I recalled that Sven makes those ridiculously small ukes and a 5mm wide rosette would look out of scale. So I got Micheal onto Sven about what size would suit him. So, I've had a couple of emails about this and if you think that you would need a narrower routing blade let Micheal know. Wider is not possible because of the tool design, but all you have to do is adjust the diameter after the first cut and continue until you get the width you want.

If 3mm width is a standard size for many then he'll make a batch of them.

Poor mans version:

I like the poor man's version. Totally stripped out!

Actually it has a great advantage. That is you set it once, then there is no need to reset it and you never lose that setting. If you want a different diameter, make another. They cost nada. I have about 15 of these things. Not my idea of course but I stole the principle for these:



Purfling cutters. Again, no messing with adjusting things. You just pick up the one that gives you the correct depth/spacing. I now have a series of commercial redundant rosette and purfling cutters.