Violin Forum/Message Board

kjb · Super Member Joined: 06 Feb 2013 Posts: 385

I am having some difficulty with control the brass part the runs along the edge, is it convex all the way down to the bottom where it shows in the picture or is it flatter at the working end?
I have tried a few different approaches to the way I am standing , I mount the plate on the bench and walk around and try to do it in on smooth motion. But I tend to get a little wiggle here and there, is this just a matter of me getting more hand control and experience. I am thinking of making the working end flatter so it cannot turn. I do not do the corners with it, just bring it up near and do the rest by hand.
thanks for any advice on this.

kjb · Super Member Joined: 06 Feb 2013 Posts: 385

http://darntonviolins.com/purflingmachine.php
here is the link

Michael Darnton · Posted: Thu Mar 07, 2013 11:29 am Post subject:

There are two contours, above the step and below the step. Below the step it's the same all the way down. I filed that section until it fit nicely into the tightest curve on my outline, which is in the armpits of the c-bouts.

Yes, it's all experience. If there's a trick to it, it's that I hang the plate off the front edge of my bench, lock the hand that's holding the tool, and use the other hand to turn the plate under the tool. The only job your tool hand has to do is keep it straight up, and twist it as needed to keep tangency to the edge. On long stretches, I push the tool up against the front of the bench and spin the plate past it, as you can see here:

If my right hand hadn't been holding the camera, it would have been splayed out flat on the plate, as wide as I could spread it, turning the plate.

I'ts important to move the tool counterclockwise around the edge so that the movement of the bit sucks the guide against the edge instead of pushing it away, so holding it in your left hand as in the photo makes what you're doing more visible, and when you have to move the tool with that hand you aren't pushing backhanded, but pulling it towards you, which is more controllable.

The other job that works better left handed is soundpost setting, and I always train people to use their left hand for that--since it's hard with either hand at the beginning, it's better to get started right off with the left hand.
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

Joseph Leahy · Posted: Thu Mar 07, 2013 12:20 pm Post subject:

Michael Darnton · Posted: Thu Mar 07, 2013 1:51 pm Post subject:

_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

Joseph Leahy · Posted: Thu Mar 07, 2013 2:00 pm Post subject:

Sorry Michael

I don't think my question was clear enough. I was referring to the comment you made regarding setting the soundpost with your left hand.

I do, however, appreciate the extra picture on the purfling cutting process. It also clarifies things.

Thanks.

Joe

Michael Darnton · Posted: Thu Mar 07, 2013 2:32 pm Post subject:

Advantages: you aren't working cross-handed; you have a clear view of the post and a more natural angle to the setter; the right hand is in position to squeeze opposite edges of the instrument diagonally (top with thumb, opposite edge of the back with fingers) to loosen the fit (I could drop the post in a strung-up instrument just by squeezing this way, if it wasn't the pushing-half-million dollar one in the photo) so you don't have to take the string pressure off to move the post around.

_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

Joseph Leahy · Posted: Thu Mar 07, 2013 2:47 pm Post subject:

catnip · Junior Member Joined: 04 May 2007 Posts: 7

I really appreciate your experience in violin making and your generosity in sharing your knowledge.

With your purfling machine are you able to cut (grove) the purfling after closing the box? That way the overhang is more consistent.

I always find that I have a bit of trouble getting a consistent overhang after purfling the top... sometimes I have to pull the ribs out a little which is not easy.

Michael Darnton · Posted: Thu Mar 07, 2013 2:51 pm Post subject:

I could do that, but I don't.
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

Cliff Green · Posted: Fri Mar 08, 2013 12:15 pm Post subject:

I've been clamping the plate to the bench with a block under the plate to elevate the edge for tool clearance. I hold the handpiece with both hands with one hand controlling the contact with the plate edge and helping to stabilize the tool. I rotate the plate to offer the best angle for each section. I'll have to give Michael's method a try.

kjb · Super Member Joined: 06 Feb 2013 Posts: 385

I did a top and back today, and it worked much better, still have some experience to gain but overall an improvement. thanks