self made useful tools or templates for violin making/repair

[Brad Dorsey]

I found that the challenge of clamping a saddle is ensuring that the clamping force doesn't tip the saddle out of its seat.  Whether it does or not depends on the saddle width, the location of the high spot and the amount the saddle overhangs the ribs.  After trying several different saddle clamping methods, I now use two rubber bands.  With these, the clamping force cannot tip the saddle out.

 

[Greg Sigworth]

On 10/2/2020 at 3:10 PM, Jim Bress said:

This is my most used jig. A basic shooting board. 

Thank you for this. I just made my first shooting board and will use it to join the plates on the next violin.

[Jim Bress]

4 minutes ago, Greg Sigworth said:

Thank you for this. I just made my first shooting board and will use it to join the plates on the next violin.

Here are the plans I made it from, although I'm sure many variations would work fine.

Lie-Nielsen-Shooting-Board-Plans.pdf

[Don Noon]

I have made tons of tools, gizmos, fixtures... many of which eventually ended up on the scrap pile.  But here's one I like, for gluing on a fingerboard.  It locates the fingerboard laterally and longitudinally at the neck root, so you only have to worry about getting the lateral position of the nut, which I find easy enough to do just with my fingers.

[Davide Sora]

1 hour ago, Brad Dorsey said:

I found that the challenge of clamping a saddle is ensuring that the clamping force doesn't tip the saddle out of its seat.  Whether it does or not depends on the saddle width, the location of the high spot and the amount the saddle overhangs the ribs.  After trying several different saddle clamping methods, I now use two rubber bands.  With these, the clamping force cannot tip the saddle out.

I use a system that avoids all possible problems: I don't use any clamps.

Perfect fit and use of fairly dense hot glue is enough for me, no saddles have ever come off. But I cut only half of the edge (not through) and the gluing surface is much larger.

[David Beard]

We need a like button for this thread.

[David Burgess]

5 hours ago, Davide Sora said:

I use a system that avoids all possible problems: I don't use any clamps.

Perfect fit and use of fairly dense hot glue is enough for me, no saddles have ever come off.

Same here. The gluing area on both a saddle and upper nut is small enough, that even semi-gelled glue can be pushed out with finger pressure to bring well-fitted parts together. I have never used clamps on either.

That said, I do understand the "wood-mashing" theory of bringing poorly fitted parts together with enough clamping force. I do not consider this to be best for the long-term.

[Mark Norfleet]

5 hours ago, Davide Sora said:

I use a system that avoids all possible problems: I don't use any clamps.

Perfect fit and use of fairly dense hot glue is enough for me, no saddles have ever come off. But I cut only half of the edge (not through) and the gluing surface is much larger.

Likewise!

One of my pet peeves though is that so many saddles seem to be designed such that tail gut forces tend to pull them away from the block rather than hold them in place.

[Mark Norfleet]

My crack end gluing clamp.  I do have to make a new part for it though...  I would also change the offsetting mechanism at the pivot if I made another.

 

[David Burgess]

11 minutes ago, Mark Norfleet said:

Likewise!

One of my pet peeves though is that so many saddles seem to be designed such that tail gut forces tend to pull them away from the block rather than hold them in place.

Mark is really good at understanding mechanical engineering, and vector forces. I agree that many saddle shapes are almost as if they were designed to fail

[David Beard]

I've taken to heating the nut and saddle when I put them.  Also, no clamp.  The heat leads them to set very quickly.

I don't remember where I picked that up.  I enjoy this method, but sometimes wonder if there might be a downside to accelerating the drying like that.

So far I don't see a downside, so I keep doing it.

[Davide Sora]

1 hour ago, Mark Norfleet said:

One of my pet peeves though is that so many saddles seem to be designed such that tail gut forces tend to pull them away from the block rather than hold them in place.

 

1 hour ago, David Burgess said:

 I agree that many saddle shapes are almost as if they were designed to fail

I fully agree.

If the curve of the saddle where the tailgut rests is well conceived, the forces involved hold it in place almost without the need for glue (well, maybe just a little because of the friction). I like to make pretty tall saddles and therefore I have always worried about this aspect, often not even considered by many who believe that it is the glue's fault when the saddle comes off...

[Don Noon]

One more vote here for good fit and finger pressure in gluing on saddles and nuts.  Even if they weren't glued, the string pressure should keep them in place (except for weirdo saddle grooves intended to shift the tailpiece laterally).

[Mat Roop]

8 hours ago, David Burgess said:

...... many saddle shapes are almost as if they were designed to fail

Ok... so what is the ideal saddle shape?... assuming a standard strad style arching height?

I've never really gave it much thought, but my habit has been : 

From the end view of the saddle I have always made the peak at the center of the saddle body .... or  should it be forward or rearward?... by how much?

As far as the curve that the tailwire follows, is concerned, I  match the saddle to the edge of the top and then  flow it smoothly to the peak, and pointing a touch above the line of the after length strings

Thoughts??  ... Cheers, Mat

PS... re glueing saddles... clean close fit & glue with hand pressure 1 minute... no preheat

[Andreas Preuss]

On 11/13/2020 at 4:17 AM, DonLeister said:

My latest gadget-

That's a cool idea. Will be on my list to make the same.

[Andreas Preuss]

6 hours ago, Don Noon said:

One more vote here for good fit and finger pressure in gluing on saddles and nuts.  Even if they weren't glued, the string pressure should keep them in place (except for weirdo saddle grooves intended to shift the tailpiece laterally).

maybe for a new fiddle. For some sound adjustments I found out that a higher saddle can bring some good results and need to be glued well.

[Andreas Preuss]

10 hours ago, David Burgess said:

Mark is really good at understanding mechanical engineering, and vector forces. I agree that many saddle shapes are almost as if they were designed to fail

In the instrument museum in VIenna I have seen a Geissenhof with an original saddle. And it was literally just the shape of the edge to prevent the tailgut cutting into the edge. Basically not more is needed if the neck angle is set right from the beginning. But there is probably the 'problem'.

[Davide Sora]

3 hours ago, Mat Roop said:

Ok... so what is the ideal saddle shape?... assuming a standard strad style arching height?

I've never really gave it much thought, but my habit has been : 

From the end view of the saddle I have always made the peak at the center of the saddle body .... or  should it be forward or rearward?... by how much?

As far as the curve that the tailwire follows, is concerned, I  match the saddle to the edge of the top and then  flow it smoothly to the peak, and pointing a touch above the line of the after length strings

Thoughts??  ... Cheers, Mat

PS... re glueing saddles... clean close fit & glue with hand pressure 1 minute... no preheat

I put the peak of the saddle more inward, about a quarter or a third of the way across, to minimize the lever arm. With regard to the curve, it is a bit the same as the nut, I take care that the tailwire follow a smooth radius without any kink. I don't know if it's ideal, but it works well for me.

[David Burgess]

The shape of the saddle I use: One view from overhead (top of photo goes toward the bridge), and another glued in place, with the pieces of paper illustrating the gap I leave at both ends:

[Davide Sora]

51 minutes ago, David Burgess said:

The shape of the saddle I use: One view from overhead (top of photo goes toward the bridge)

 

Maybe the other way around?

[catnip]

From my notebook ... a long time ago.  I am not sure of the original source.   I make sure the saddle fits well and does not rock and glue it with just a dab of hide glue with no clamp ... very similar to fitting a nut.

[DonLeister]

5 hours ago, Andreas Preuss said:

That's a cool idea. Will be on my list to make the same.

That is the first time I used it. At first the saddle tilted back a little but I pushed the lower jaw in a bit and the saddle seated itself. 

There is no 'slop' between the jaws, the clamp has no barrel nuts like the bigger wooden kind. Originally it had 2 identical plastic jaws. I think it is good to make the endpin jaw a little small so it can go in and out as needed.

[David Burgess]

2 hours ago, Davide Sora said:

Maybe the other way around?

No. Here's my thinking on this:

The total downforce on the saddle will be the same, no matter where the "break point"  or ridge is located. Since the most common situation is for a saddle to roll forward if it comes unglued (raising the rear of the saddle), I like to put the downforce more to the rear of the saddle, helping to hold that part down, by putting the break point closer to the perimeter of the outline.

Does that make any sense?

[Davide Sora]

29 minutes ago, David Burgess said:

No. Here's my thinking on this:

The total downforce on the saddle will be the same, no matter where the "break point"  or ridge is located. Since the most common situation is for a saddle to roll forward if it comes unglued (raising the rear of the saddle), I like to put the downforce more to the rear of the saddle, helping to hold that part down, by putting the break point closer to the perimeter of the outline.

Does that make any sense?

Looking at the second photo you posted it seemed to me that it was the other way around, this is the reason for my guess.

I suspect it probably depends more on the shape of the curve and how the pressure of the tailwire is applied across the surface, and the direction of the resulting vector force.

It would take an engineer who makes the right calculations, I don't venture further...

Anyway this is my saddle, it's not clear where the apex is but I'm sorry I don't have better photos, even if it tends to be more like in the Catnip's drawing (more or less 1/3 from the inside) but more radiused and less peaky at the apex. some rounding will still need to be done once glued.

[Don Noon]

57 minutes ago, David Burgess said:

No. Here's my thinking on this:

The total downforce on the saddle will be the same, no matter where the "break point"  or ridge is located. Since the most common situation is for a saddle to roll forward if it comes unglued (raising the rear of the saddle), I like to put the downforce more to the rear of the saddle, helping to hold that part down, by putting the break point closer to the perimeter of the outline.

Does that make any sense?

29 minutes ago, Davide Sora said:

It would take an engineer who makes the right calculations, I don't venture further...

OK, I can take a hint.

As it turns out, the defining geometry is pretty well set by the saddle height and the angle of the tailgut on either side of the saddle.  Reducing the saddle to the ridiculuous limits:

The resultant force vector magnitude, angle, and location are the same no matter where you put the breakpoint... as long as the "effective" saddle height is the same (the actual saddle height of the one in the right diagram would be slightly lower to get the same effective saddle height, i.e. the same tailpiece geometry).  

The diagram is for a mostly frictionless condition, but adding friction wouldn't change the result.  Vector b would be larger, and a would be reduced, but there would be no difference between the two saddles as to the resultant vector.

The crucial thing to me would be to keep friction down, by having a very smooth curve.  Lubricating the saddle with wax or something should help avoiding the levered-out problem, which would be mostly due to friction.  Naturally, a higher saddle height also would add to the problem.