Violin Forum/Message Board

[Michael Darnton]

I'm still not sure what you mean. The cutter should be sucking the wood against the stop, not pushing it away, though. For RIGHT-handers using a handheld tool, that means pushing it away from your, backhand, basically blind. I'm a lefty, so it works very well for me, pulling towards me.

[famuswood]

Michael - Your photograph shows the purfling channel cutting left to right. You have the tool between you and the near side of the plate. With my stationary setup, I'm on the other side of the plate - pushing it toward the cutting guide and the bit traveling the same direction you are. I hope that is more clear. I found that if I tried to cut the other direction I had less control.

[Michael Darnton]

Oooooo. I made a horrible mistake in my post above and just corrected it--for RIGHT handers it's backhand. Anyway, you drive the tool counterclockwise around the plate. :-)

[famuswood]

I'm left handed also. I see what you mean about seeing the cut using your left hand. If I get up the courage to hold the tool by hand, I see that that is a significant advantage.

[John Cadd]

One or two questions,thinking about the grain of the wood when using a motorised cutter.Does the cutter take the full width of the purfling or do you stay narrower and do an inside cut then an outside cut?
Where should one stop when approaching the corners and top of the back? Is all this done better using a magnifier even if you have perfect eyesight?Do splinters or dust require safety glasses in any case?

[John Cadd]

I always found the most difficult part of the (non motorised) purfling job was keeping the cutter vertical and not letting it swivel left or right.
Have you tried a cutting table with a flat surface for the plate to slide on with the cutter fixed vertically at the correct clearance point so the drill could rise and fall with the on off switch operation (gently spring loaded)?Both hands could control the plate this way.
Is the cutting best done in one run or a series of gentle pushes?

[rs]

I used a router on the last two fiddles I did.

I use a bit the same width as my purfling, 1.3 mm.

I use safety glasses! (And earplugs).

I have learned to address each cut and gouge on a fiddle with purpose. The router only works if it is operated with the same sense of confidence. The only mistake I made was when I rounded the lower bout and slowed because of hesitancy. I at that point lost confidence. It was happening so quickly. The cut wobbled a bit. Cutting with confidence and purpose avoids this.

I use no magnifier.

I cut the part under the button and the corners until the "beestings" by hand.

That is just me.
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Randall Shenefelt

[byacey]

I have a footswitch as well for the Dremel. The last thing you want is to be fumbling trying to shut it off with the cutter still in the channel.
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Bill

[Andres Sender]

You want to do each section in one pass because even with a machine and guide the exact distance of the channel from the edge varies slightly depending on the movements of the operator, so doing it the same way twice is difficult.

You stop just before the point where the purfling channel needs to depart from the set distance from the edge, and this will depend on what sort of corner you are doing. This will range from stopping just where the channels meet, to stopping something like 3-4 cm away if you were emulating certain Amati corners. At the button you may want to stop before the guide hits the button to avoid the risk of making the bit wobble.

Eye protection is always recommended when using any power tool. A magnifier might be helpful with some machines but the real issue is not seeing exactly what's going on so much as getting exactly the right relationship of the machine to the edge. This takes practice.

Wood grain can affect the pace of pushing things around, but not really anything else in my experience--that's one of the nice things about a power tool for this job.

The flat table idea has been mentioned a few times already in this thread I think.

[Oded Kishony]

Tom Croen makes a very nice fixture for doing purfling with a foredom tool

http://tomcroenviolins.com/new_page_7.htm

I use a small router (RotoZip) or a laminate trimmer with a plastic guide so I can see where I'm cutting more clearly

Oded Kishony

[John Cadd]

Thinking back to the Heron -Allen suggestion ,would a coat of thin glue applied to the purfling area stabilise the top plate grain cutting?I think you all enormously brave to have mastered this part of the art.

[Michael Darnton]

It doesn't hurt, and doing the edge of the edge as well helps prevent crushing the edge between the grainlines from the deathgrip you'll have on the tool while you're getting used to it.

[Fiddlers3]

[famuswood]

Using the Dremel tool before assembly worked well for me. In retrospect, it is quite important that your glue up of the top and bottom plate be accurate. Cutting the purfling channels before assembly doesn't leave you much wiggle room if the plate overhang is inconsistent since you have already established the purfling distance from the edge. This potential problem is avoided when you cut the channels after assembly. Some builders use a dremel tool after plate assembly but I decided that that would be too risky at my level of skill. I don't know about others, but after all that work on plate carving, I wanted to feel relatively confident in my approach. I used 1.3mm purfling and a 1.3mm cutter. The cutter jig was static and I moved the plates around using two hands to be at my steadiest. I've read other posts that state going to 1.4 purfling should work with a 1.3 (.051 inches) cutter bit as well. Always test before cutting into your plates. http://www.robbjack.com/ has the bit I bought which is SR-2-051. Best of luck to you!
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I love the feel of wood in my hands - the smell of fresh cut lumber and the challenge of a difficult woodworking project on a sunny day . . .