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Joel Pautz

DIY string jack

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Hi all,

I started drawing out a violin sized string jack based off this design I found online: http://www.scavm.com/Bridgejk.htm

I'm thinking I'd like to divide it a little more equally in half (with a taller base) and make feet at the bottom to ensure that pressure is distributed over bassbar and soundpost. I was wondering if anyone could comment on what makes a good bridge jack, design flaws to be avoided.

Thanks,

Joel

 

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That design looks OK to me, but I too would cut out a section in the lower bottom center to ensure contact at the bass bar and soundpost positions.

If I were to make one, I might make the lower section from a De Jacques bridge, to incorporate the swiveling feet. :)

 

 

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Joel,

The most important thing in my opinion is to make it as thin as possible so you can get it right up against the back of the bridge you are removing. Otherwise you have to crank it pretty high to get the other bridge out increasing tension on the fiddle. 

The nicest ones I've seen were the ones made for the Wurlitzer shop which were  steel and only about 3 mm thick. I made one years ago and replaced it with a commercial one as soon as I could.

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Addie, I like your design.  The store bought ones can damage the top.  I  think there is no penalty to making the device as wide as possible to spread the load.  Danger may be in adding pressure to the top between bass bar and soundpost where it hasn't had pressure before.   I have the Hardeim and use it a heck of a lot refining the bridge.

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20 hours ago, nathan slobodkin said:

The nicest ones I've seen were the ones made for the Wurlitzer shop which were  steel and only about 3 mm thick. I made one years ago and replaced it with a commercial one as soon as I could.

I'm still using the Wurlitzer bridge jacks too, and feel lucky to have them.

The Herdim jacks may be fine too, have never worked with one over a period of years.

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I stopped using bridge jacks for the most part after it left indentations on a handmade instrument about a year old. It didn't strike me as particularly soft varnish, and the indentations were light enough that they could probably be French polished out, however, this varnish had a lot of texture and corduroy effect to the spruce, so I thought that messing with the texture over a wider area would be worse than the little indents left by the jack. I thought it was strange because the indentations under the bridge were not extreme, which I would think would also suggest softer varnish. I checked over my bridge jack, and the pads were still there, didn't have any hard object stuck to the bottom, just couldn't explain it.

In any case, even if it's rare I just didn't think the little time savings was worth the small risk of damaging a nice varnish, so I stopped using it.

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Tim, I use a piece of rib lining stock, bent to roughly the shape of the cross-arching,  between the bridge jack and the fiddle to help distribute the load over a broader area. Also, I try to minimize the time that the bridge jack is in place.

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Perhaps it's just me, I only ever really use a bridge jack when I'm switching out summer to winter bridges on 'celli and back again.  If I'm taking the bridge off of a violin it's usually to cut a new one, fit a new post, dress the board, change the after length - making the need to keep tension on the instrument not critical or impossible to maintain.  What are you all using them for?  I will admit to wanting a vintage wurlitzer bridge jack, mostly for "workbench bling."  

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Jerry, I will use mine to remove a bridge for final trimming/cleanup after fitting and setting the string heights. Or for things like gluing on parchments. I usually tune the strings down at least a fifth before using it.

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After learning how to fit bridges from David B's classic video, I've found that a bridge jack just gets in the way of the Sawzall stroke, so I don't use it anymore.

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14 hours ago, David Burgess said:

Tim, I use a piece of rib lining stock, bent to roughly the shape of the cross-arching,  between the bridge jack and the fiddle to help distribute the load over a broader area. Also, I try to minimize the time that the bridge jack is in place.

That makes sense. I've taken to using a little velcro cable tie and wrapping it around the neck near the nut, then sliding it down towards the bridge so it snugs itself up as the neck gets wider. Then slide a little piece of foam under the tailpiece, which also has velcro pre-attached if I want to use it.

For the most part, if I'm tuning it down a little anyways, I mostly just want all my strings in the pegbox to stay nicely arranged. The rest doesn't matter much, since the post shouldn't be shifting around and the tailpiece won't be changing. I don't often find myself missing the bridge jack.

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