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Spiral Bushings for new setup for violin #2


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#1 catnip

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Posted 27 January 2008 - 11:35 AM

I am about to ream the pegholes for violin #2 and was wondering if purposely putting in spiral bushings (paper thin curl of maple maybe just 2 turns) was a good idea? I have noticed that on violin #1 the pegs have move in about 2mm from the original setup.

What about just sizing the new pegholes with thin hide glue prior to the final fitting of the pegs?

What diameter bore hole should one aim for? I could not find this dimension listed as one of the standard measurements.

I have measured some new violins and have found the peg bore to vary between 7.4 mm to 7.9 mm.

#2 MANFIO

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Posted 27 January 2008 - 12:31 PM

You can make spiral bushing with craft paper, it has been commented here in older threads.

#3 Janito

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Posted 27 January 2008 - 01:43 PM

As the last person who should comment, here goes:

I cannot understand why you would want, a priori, to design-in spiral bushings. Good peg fitting technique will pay rewards later. Practice on offcuts till you get it right, before tackling the pegbox and pegs themselves.

I would not size the peg holes with glue - humidity and heat changes might soften this and gum up the pegs. [There are MN threads on ingenious methods to tackle stuck pegs.]

I use the smallest peg shaft bore I can get away with (I will alter the peg-head to keep shaft in proportion with the head). This improves the ability to tune accurately. Remember that the greater the diameter of the peg, the more the string will wind round for a small amount of peg-head movement.

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#4 FiddleDoug

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Posted 27 January 2008 - 01:47 PM

I've done spiral bushings quite often to bush out old, worn peg holes rather than putting in boxwood bushings, re-drilling and reaming. I also think that the spiral bushing might be stronger. Make sure to wind the bushings in the correct direction, so that you're going with the spiral rather than against it when reaming. I use a tapered mandrel (waxed, so glue doesn't stick) to hold the spiral in place while the glue dries. I've been taught to use Tightbond glue for this application. Ream lightly to fit after the glue has dried. I wouldn't size the pegholes with glue before fitting pegs. If things ever got damp, you might end up with glued in pegs.

#5 Brad Dorsey

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Posted 27 January 2008 - 02:13 PM

"What diameter bore hole should one aim for?"

Here's how my peg hole sizes are determined: First I shave the pegs until they are all the way in the largest hole on the Dick 4-hole peg shaver for small violins. Then I ream the holes until the pegs stick out the distance I want (about 40mm from the outside of the pegbox to the extremity of the peg knob for a full-size violin).

This means that I'm starting out with my new holes a bit on the small side -- about what would probably be normal for a 3/4 size violin. I want it to be a long time before the holes wear big enough to require bushing.

I have never measured the hole diameter; it would vary depending on how far the pegs stuck out. I'll try to remember to measure one and edit this message with the result.

Edit: The diameter of my new peg hole is 6.9mm measured at the outside of the pegbox on the larger hole.

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#6 catnip

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Posted 27 January 2008 - 02:42 PM

Thanks for all the advice. I now realize why sizing a peghole is a very bad idea! I will keep spiral bushings for future repairs for over-sized pegholes.

And I can see titebond or white glue for the bushings would be preferred over hide glue because of the possibility stuck pegs in areas of high humidity.

#7 captainhook

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Posted 27 January 2008 - 09:18 PM

quote:


Originally posted by: catnipI have noticed that on violin #1 the pegs have move in about 2mm from the original setup.


A common problem. The Chinese just fit the pegs a little shy of going all the way through, but I believe Michael Darnton recommended burnishing the peg holes by turning the reamer backwards a few turns after getting the size you want. This seems to minimize movement of the pegs into the holes when I can remember to do it. Also don't leave the pegs too rough or they quickly wear in.

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#8 Andres Sender

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Posted 28 January 2008 - 02:01 AM

Start burnishing BEFORE you get to where you want to end up.

MD doesn't advocate using the reamer for burnishing. Use a peg or something purpose-made, and spare the reamer.
The problem with the ignore feature is that if one has a sort of morbid fascination for train wrecks one can keep peeking and then the benefit is out the window.

#9 David Burgess

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Posted 28 January 2008 - 06:08 AM

I do the last 5-7 mm of insertion (depending on how hard the wood is) by turning the reamer backwards, lubed with soap.
As long as customers don't use an abrasive on the pegs (chalk, pumice, "lava soap" etc.), they typically move in very little after years of use.

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