Andreas Preuss’ New Concept Violin (formerly: super light violin)

[Nick Allen]

3 hours ago, Andreas Preuss said:

Would be very resistant, but is too much on the surface. 

Is it at all possible to impregnate the wood with some kind of binding agent?

[Andreas Preuss]

On 5/25/2018 at 2:13 AM, Nick Allen said:

Is it at all possible to impregnate the wood with some kind of binding agent?

005-49.1 This would be the idea. I think even normal hide glue is not bad. With an after treatment of formaldehyde it becomes absolutely water resistant. This might be actually a better idea than amber varnish.

[Andreas Preuss]

005-50.1 I forgot actually to mention the most important thing here: all is about weight and the scroll with the spruce (actually red cedar)graft weights as shown on the picture 62g. I guess I can come down to below 55 when the neck shape is complete.

[Andreas Preuss]

005.51.1 So next is the bending of the top plate. 

Below I made a diagram how I developed the main idea.

The Michetschlager Brescian arch interpretation drives the wedges in between the two plates in a perpendicular direction to the grain. This makes the corners lift up when not clamped firmly. (diagram 1: circled areas)

51.2Therefore I came up with the roof fold idea. When wedges  are driven in between the two boards in diagonal direction the thing becomes a little bit easier. The  problem here is that the deepest dip at the C bouts is lifting up too much. (diagram 2: distance to point A)

51.3 From there I thought it would not make a big difference to bend the center part of the roof in a concave curve and finally round of the folding line (green dotted line to get closer to the violin arching there too.

51.4 When finished my two bending boards looked like this (photo) The pencil lines are at the same height and follow (more or less) the inside rib line. With a 7mm thick board the glue surface of top and lower block will be big enough when the underside of the bent plates is trimmed into one plane. there will be as well enough material at the c bouts to carve the cross arching at the c bouts. 

 

 

 

 

 

[Andreas Preuss]

005-52.1 If I were very bold I would say this is THE explanation why Cremonese top archings have, when viewed from the side, always a flat zone in the center. 

[JacksonMaberry]

5 minutes ago, Andreas Preuss said:

If I were very bold I would say this is THE explanation why Cremonese top archings have, when viewed from the side, always a flat zone in the center. 

You are suggesting the Cremonese bent their plates?! Brace for impact haha

[Andreas Preuss]

On 5/30/2018 at 3:32 PM, JacksonMaberry said:

You are suggesting the Cremonese bent their plates?! Brace for impact haha

005.53.1 I rather tear down the defense myself right away.

It can't be because the grain at  both block surface areas runs inside the arch and restorers would have seen that since long. Secondly you can't really use one piece tops with this method. Thirdly  bent plates are usually recognized at the weird grain direction along the center line.

53.2 It was just that when I finished the mould I thought,  if you try to make a completely round center line things get a bit complicated, so the flat zone just comes naturally out (like in Cremonese instruments?)

 

[JacksonMaberry]

I agree! Although I disagree on one point alone - depending on the parameters of the arching, it is possible to bend a one piece top using technologies that would have been available in the late Renaissance. 

[Torbjörn Zethelius]

I suspect that we would see less diversity in Cremonese archings if they were bent. No?

[Andreas Preuss]

On 5/30/2018 at 5:01 PM, Torbjörn Zethelius said:

I suspect that we would see less diversity in Cremonese archings if they were bent. No?

005.54.1 Yes, you are right Torbjorn. This was a kind of joke.

Cremonese archings were not bent, but carved for the reasons I explained above. For a while I was thinking about a half bent procedure, but this is a kind of getting too complicated.

54.2 For me it is interesting in the super light violin  project to look into new wood working techniques.  What I find intriguing here is that one can think and develop a technique where the bent curves depend on the material used. This means that the wood tells me which shape it wants to have.

54.3 Lets say you have a soft plate and a rigid plate and bend it not with clamps but with weights, then in theory the curves a soft plate should get a higher arch than a rigid plate which is desirable. Then any calculations are not necessary, the wood tells me what shape it wants to have.

54.4 In the end we work with wood and I got a kick on everything which explores the properties of this wonderful material.

 

[Andreas Preuss]

On 5/30/2018 at 4:34 PM, JacksonMaberry said:

[...] depending on the parameters of the arching, it is possible to bend a one piece top using technologies that would have been available in the late Renaissance. 

005.55.1 It is your turn to show how this works, Jackson!

Last night I was thinking about that, too.

[JacksonMaberry]

1 hour ago, Andreas Preuss said:

It is your turn to show how this works, Jackson!

Last night I was thinking about that, too.

As soon as I have a moment to put together a demonstration, I shall. Just to tease you, I'll say that it requires an apparatus similar to what you'd find in a lute makers shop, as well as a common household chemical known to the early Arab alchemists. 

At any rate, I hope I can sit down with you and chat someday. We seem to share a number of interests within violinmaking.

[Andreas Preuss]

On 5/31/2018 at 3:43 AM, JacksonMaberry said:

As soon as I have a moment to put together a demonstration, I shall. Just to tease you, I'll say that it requires an apparatus similar to what you'd find in a lute makers shop, as well as a common household chemical known to the early Arab alchemists. 

At any rate, I hope I can sit down with you and chat someday. We seem to share a number of interests within violinmaking.

005-56.1 Would be my pleasure.

 

[Torbjörn Zethelius]

16 hours ago, Andreas Preuss said:

Yes, you are right Torbjorn. This was a kind of joke.

Cremonese archings were not bent, but carved for the reasons I explained above. For a while I was thinking about a half bent procedure, but this is a kind of getting too complicated.

For me it is interesting in the super light violin  project to look into new wood working techniques.  What I find intriguing here is that one can think and develop a technique where the bent curves depend on the material used. This means that the wood tells me which shape it wants to have.

Lets say you have a soft plate and a rigid plate and bend it not with clamps but with weights, then in theory the curves a soft plate should get a higher arch than a rigid plate which is desirable. Then any calculations are not necessary, the wood tells me what shape it wants to have.

In the end we work with wood and I got a kick on everything which explores the properties of this wonderful material.

  

I can imagine that a bent top would have less creep. You could even make a super thin two ply top. I wonder how that would work?

[Andreas Preuss]

On 5/31/2018 at 6:48 PM, Torbjörn Zethelius said:

I can imagine that a bent top would have less creep. You could even make a super thin two ply top. I wonder how that would work?

005-57.1 Two ply? Do you mean two layers glued together? Would be interesting, but with spruce it is not so easy. I was thinking about a japan paper reinfoircement too, just like the ribs.

57.2 However, if I can manage to do just the natural wood strength, I'll be happy.

[Andreas Preuss]

On 5/31/2018 at 3:43 AM, JacksonMaberry said:

Just to tease you, I'll say that it requires an apparatus similar to what you'd find in a lute makers shop, as well as a common household chemical known to the early Arab alchemists. 

 

005-58.1 My guess is ammonia and a mould (on the same principle as the bent strips for a lute back)

[JacksonMaberry]

49 minutes ago, Andreas Preuss said:

My guess is ammonia and a mould (on the same principle as the bent strips for a lute back)

That's right! Though I have my suspicions that the ammonia doesn't do that much. My next try will be to do the same with just an extended warm water soak.

[Andreas Preuss]

On 6/1/2018 at 4:42 AM, JacksonMaberry said:

That's right! Though I have my suspicions that the ammonia doesn't do that much. My next try will be to do the same with just an extended warm water soak.

005-59.1 There is a You tube about bending wood with ammonia. For spruce it seems to work but not as dramatic as for certain hard woods: There is somewhere a demonstration of bending a maple strip into a knot!

[JacksonMaberry]

3 minutes ago, Andreas Preuss said:

There is a You tube about bending wood with ammonia. For spruce it seems to work but not as dramatic as for certain hard woods: There is somewhere a demonstration of bending a maple strip into a knot!

That's true! I think I've seen the same video. I first learned of it through Bruce Hoadley's books. They are using anhydrous ammonia though, which is a very different beast from what I can buy in the store. Anyway, please forgive the digression. At some point I will write to you personally and ramble about my nonsense. 

[Torbjörn Zethelius]

10 hours ago, Andreas Preuss said:

two ply? Do you mean two layers glued together? Would be interesting, but with spruce it is not so easy. I was thinking about a japan paper reinfoircement too, just like the ribs.

However, if I can manage to do just the natural wood strength, I'll be happy.

Yes, I meant two layers glued together, like plywood. Imagine a belly with the year rings going transverse.

[Andreas Preuss]

On 6/1/2018 at 10:44 AM, Torbjörn Zethelius said:

Yes, I meant two layers glued together, like plywood. Imagine a belly with the year rings going transverse.

005-60.1 But you would need to do that over a mould which has the arch shape, or not? 

You can bend maple to any shape you want, but spruce is more difficult.

[Torbjörn Zethelius]

8 hours ago, Andreas Preuss said:

But you would need to do that over a mould which has the arch shape, or not? 

You can bend maple to any shape you want, but spruce is more difficult.

I would think it was easier. I haven't worked with bent plates though.

[JacksonMaberry]

On 4/22/2018 at 6:24 AM, Evan Smith said:

yes many years and hundreds of them, one piece or two,  what do you want to do ?

Evan, would you be willing to share your notes on bending a one piece top?

[Andreas Preuss]

On 6/1/2018 at 8:25 PM, Torbjörn Zethelius said:

I would think it was easier. I haven't worked with bent plates though.

005.61.1 The major problem in bending spruce is that it can crack very easily along the grain.

 

[Evan Smith]

19 hours ago, JacksonMaberry said:

Evan, would you be willing to share your notes on bending a one piece top?

Sure,,,

But for today I'm done typing long winded dirges,, work calls