Splicing on a sawed-off button

[Don Noon]

Luddites and purists please exit now, before your blood pressure goes up.

This is how I fixed my oopsie on violin #5.

First, I sliced up the saved chunk of billet to get 2 button blanks, slightly thicker than the plate. I cleaned up the visible surfaces, put on some clear shellac to make the grain and flame easier to see, then marked the plate and buttons to match up the grain and flame as best as I could.

Then I used my purfling routing bit to make the rectangular cutout, with the joint area in the middle of the future purfling groove.

Flipping the plate over and using a larger router bit, I milled the pocket to ~2.5 mm depth, taking care to match up exactly with the edges of the previous cutout.

Aligning the center joint, the button width is marked onto the blanks.

Button blank milled to exact width

And the "tongue" is milled to thickness... slightly more than the depth of the pocket

Drat. A bit of the button edge split off and disappeared during milling. Rather than use the spare, I cut a sliver to jam into the gap.

TAAA DAAAA! Done. Except for the cleanup.

[~ Ben Conover]

Why did you saw it off ?

Seriously, there must be a reason. I've nearly done it loads of times.

One thing I do to remind myself not to saw through it, is to mark on the finished shape with pencil.

Then as I approach it with my coping saw, I cut right to the finshed line, leaving 1mm to trim.

Very nice router work.

I suppose you've read the button graft in Weisharr's book, it's good. Not so tricky to do with a chisel, and I'd feel safer away from that big routing table. What else do you use the table for ?

Cheers.

[Don Noon]

...I'd feel safer away from that big routing table. What else do you use the table for ?

It only looks big 'cuz of the closeups, and it's not a router table. It's a small milling machine, to which I have adapted a foredom handpiece to get higher spindle speeds.

I the machine use it for:

Routing purfling grooves

Squaring up neck blocks

Drilling peg holes in neck blocks

Drilling holes in pegs

Precision thicknessing of wood samples

Milling locating slots in fingerboards (I use a pin near the nut, and a removable square "pin" at the heel)

... and tons of miscellaneous jobs making fixtures, tools, etc.

I think a mill is much safer than many other machines, as hands and digits are far away from the action, just turning the handles (except in the case of routing the purfling grooves). Everything is clamped down.

[~ Ben Conover]

Cool, thanks.

[Roger Hill]

Luddites and purists please exit now, before your blood pressure goes up.

Drat. A bit of the button edge split off and disappeared during milling. Rather than use the spare, I cut a sliver to jam into the gap.

Hi Don:

I have found that when milling cuts with the grain, if I am meticulous about "climbing the mill" I never get a split out. The maximum distance of split is the distance the cutter travels along the table during one revolution of the cutting tool, divided by the number of flutes on the tool. Works well. Have you tried using the mill to join and flatten plates? That too works well but requires a bootstrapping into flatness which probably takes more time than planing. With regard to planing the edges to join, I lack the woodworking skills and the mill is invaluable.

[jezzupe]

"You can lead a rocket scientist to a new back plate, but cha' can't make em' use it"

Don I can see the reasoning behind the repair, and it is "skillful" to test ones skills and come up with solutions to problems, but are you not concerned about putting all the effort into the violin in its entirety with a potentially weak spot in such a critical area?

[Don Noon]

Roger,

This particular split was from milling across the grain, and reaching the end. If I could reverse the spindle roatation and use a reverse-rotating cutter, that would help (silly, though). Or do that cut first, then mill the width. Not a big deal, though. My choice for a "fix" would be to watch for splitouts, save the piece and glue it back on for a later chisel cut.

My mill is way too small to do plate joints or surfacing. So I have a jointer that I have put a lot of work into to make sure it makes dead-flat cuts. It works amazingly well.

Jezzupe,

I doubt the button is any weaker now than if it was not cut off. The joints are all tight and straight, and the glue is stronger than the wood. Even under the purfling, the small remaining butt joint is perfect. There is no way I would trash this back... 40 year old, beautiful flame European maple.

[Michael_Molnar]

Sawing off a button is an easy mistake when you are routing the plate shape and moving too fast.

Done that. Been there.

Mike

[David Burgess]

Geez Don, you had a chance to do something really innovative there, like put a step in the neck heel so it will overhang the un-rounded edge, creating a button which is one-piece with the neck and can never break off.

[Don Noon]

Geez Don, you had a chance to do something really innovative there...

Sorry, this is my "traditional" violin... unprocessed wood and all that.

I'm using all my innovations on the other one: Snakefiddle II.

[NewNewbie]

Luddites and purists please exit now, before your blood pressure goes up.

This is how I fixed my oopsie on violin #5.

Don have you thought of sending this to The Strad as an article on fixing slip ups?

Most of us Luddites don't like to admit to our non-purist mistakes, so we just pretend to be shocked when someone cuts their butt ...on off!

Every year in violin schools the 2nd year students watch to see which 1st year student will cut their butt ..on off and it almost always happens.

It can be a cruel world sometimes.

[jezzupe]

Sorry, this is my "traditional" violin... unprocessed wood and all that.

I'm using all my innovations on the other one: Snakefiddle II.

Snakefiddles 2...ON THE PLANE!!!......AHH!!!!!!!

Is that one in your avatar snakefiddle 1? if so, please post some pics of it, I have always wanted to get a closer look at it

[~ Ben Conover]

http://kremer-pigmente.de/Texte/beer-glaze.pdf

[Don Noon]

Snakefiddles 2...ON THE PLANE!!!......AHH!!!!!!!

Is that one in your avatar snakefiddle 1? if so, please post some pics of it, I have always wanted to get a closer look at it

The late Snakefiddle 1 was previously posted here.. Top and back were dead flat.

[Will L]

Since there are certainly some new makers who might not realize how easy it is to make this mistake, I'd suggest going one step further than Ben does when he recommends marking the lines. I recommend starting with making the cuts first on either side of the button before starting with the outline. It's sadly easy to even cut through a warning pencil line. Also, as silly as this sounds, if one leaves button material on the top ALSO as a routine, one never will cut off the material on the back by mistake. Another way of putting it: establishing the same routine for top and back means you don't have to stop and think which one you're cutting. I don't do this myself, but it's a logical idea for the truly forgetful. I ain't too proud to do silly things, since I already paid my dues to the Button god.

Will L

[Don Noon]

To save wear and tear on my old, fractured, arthritic wrists (not to mention giving a faster and better result), I made up a fixture to be able to route the last bit of arc across the button. Only works with the overarm/pin routing arrangement, though.