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This is a Dremel, with a jig that has been modified. I don't know if he designed it or not, but I copied Will Whedbee's.

The tracing edge is lowered to match the instrument edge thickness, a hole is tapped, and a screw and washer are added to create a step that rides the top of the instrument as well. This allows it to be used on the flat surface, but it further helps control the depth of the cut.

do you have any problem with jig to the edge contact? seeing it? I used the stu mac on my last two #6&7 but some areas got frightingly deep so I like the Idea of the washer.

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Chris, I use one of the Kutzall carving burrs in my drill press. Not as aggressive as the mill, I like my fingers just the way they are. The one I use is the donut shaped one with the silver r

Hi Chris I started working on a violin a few years ago but had to put it off because of illness. I'm getting back into it now. If I remember right, at that time I believe Michael Darnton

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do you have any problem with jig to the edge contact? seeing it? I used the stu mac on my last two #6&7 but some areas got frightingly deep so I like the Idea of the washer.

You can't see the edge, because it's covered by the washer, but you can see the channel you're cutting. It is particularly useful with cellos because, often, despite you're best efforts to flatten, once you rough arch the plate some edge warping happens, making the purfling jig harder to use with a flat surface alone.

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Smart idea-- I used that tool (as it came from the factory) and cut a neat slot right through my plate, for the exact reason you state. I cut thin strips of wood, glued them in to fill the slot and went on. But I think I will modify my jig in similar fashion. I'd like to add a blower, too, so that the buildup of wood dust doesn't occlude the edge.

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One mistake that many people make is trying to complete material removal in one pass. Haste makes waste and is dangerous.


Trying to remove too much wood in one pass can cause some of the cheaper bits to overheat and scorch the wood. Since these bits are so tiny it is also easy to break them by trying to make them cut too much in one pass as well.

I buy a bit that is a little narrower than my purfling. Then I cut the channel in two or three passes, all in the same direction, which tends to widen the channel a bit since I can't hold the StewMac routing jig exactly the same for each pass. Then this slot is usually a little too narrow for my purfling to fit into so I selectively scrape my purfling thinner until it fits in the channel. I thin the purfling alternately on each of the sides so that the blacks come out with a not quite uniform thickness, makes it look more handmade and less like mass produced purfling.

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Guest EdwardPA


McMaster-Carr is a good source for rotary files, etc. I believe that is where Michael got his, since it is also in Chicago.


Hello Doug

I think you're right it might have been McMaster-Carr. Nobody seems to carry an 1 1/4 or 1 1/2 inch size. I'll have to go with a 1" one.

Might be better, as a retired Tool & Diemaker, I rather have my fingers near a 1 inch cutter than an 1 1/2 inch one. :rolleyes:

Thanks for the link. Regards


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Here is a copy of my notes from Michael:

***NOTE that he grinds off the bottom teeth if present***

Micheal Darnton Rotary File

1"x1" Rotary file (the coarsest you can find--and make sure it's a good one, which will cost about $20, not a $5 one)in the drill press, set 4mm over a fresh table topper of plywood, used at the highest speed. If you get one with teeth on the bottom (flat end) grind them off using a bench grinder and a power drill to spin the file (make the end a bit hollow and you'll be even happier.) Wrap all but the last 4mm with masking tape so you don't get chewed on. If the top wood is soft you can rip off the edge or corners when you are climbing grainlines--do these areas VERY carefully in the wrong direction.

I rough carve to about 6mm and then take the edges down 1mm at a time to final thickness. Watch your fingers--don't put them near the edge on the sucking-in side, and work pushing against the file, not resisting the draw into the work.

It does a beautiful job and can be quite frightening the first few times. Don't call ME if it walks over your hand and rips it to shreds! But I've never got hurt. I once talked to someone who used a Wagner Safety-Planer, but that cuts TOO well--let the wood lift up and it will cut right through it. The file with plain end won't, since there are no teeth on the bottom.

If you want to be ****Traditional**** use your single-bladed purfling cutter to cut in from the side of the plate at the right height all around. It will cut in far enough to do a great job, and then you just gouge down to the cut and you have a finished edge. I think I (re-)invented this idea after noticing that most classical period violins have the purfling in from the edge almost exactly the same distance as the edge thickness on any particular violin. What could be easier than to use the tool set the same for both jobs? You read it here first :-)

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Some of you may have met Tom Croen at VSA. Many of you saw his FINE viola in the Hors Concours Exhibit.

What you may not know is his tool making skills. Check this out: purfling cutter .


I think my question just got stampeded by the Dremel tool enthusiasts...I'll try again...

Does anyone out there own or have seen one of these up close...The idea looks great but will it hold up? How does the top allen screws hold the handpiece. If it is well built (actually CNC'd) then I don't think $191.00 is a bad price. I'm interested...but hate to buy one only to be dissappointed...then out the money. More pictures would be very helpful. Thanks.


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