Shaping the corners outline.


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Hello I posted a few days ago asking how to do the center joint properly without any gaps. That has been settled. I moved on to cut out the outline of both the top and the back using a bandsaw.

I do have a small problem though. I don't have the slightest clue as to how i should mark/shape the corner outine shape. I am working from a strad poster which I mainly bought for the arching templates. But I don't plan to do any antiquing on the final instrument and because of that it would look weird if the corners where worn out but the varnish looked new. In the picture you can hopefully see that I left a bit more material in the corners area in order to shape their outline properly.

Any tips on how to do that would be really helpful and greatly appreciated since it is my first violin and thus I have no experience in the matter.

 

IMG_20210122_162731.jpg

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11 minutes ago, Nestorvass said:

 

Any tips on how to do that would be really helpful and greatly appreciated since it is my first violin and thus I have no experience in the matter.

 

 

I find it helpful to make myself a corner template, since all 8 corners should at least look related to each other. It would be quite enough to do that with some scissors and a square of old cornflake packet

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8 minutes ago, David Burgess said:

You could draw some inspiration from the corners of the Messiah Strad, which has almost no wear. Perhaps from the Lady Blunt, too.

Thank you, thats what I was planning to do but I don't know if the mold where the violin is built on plays a factor in the corner shape. I am making my violin on the p form but the messiah and the lady blunt are built on the pg. Also I don't have the measurements as to how much overhang there is at the corners so that is why I avoided it at first. But I will look into it and maybe find some information about the overhang.

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4 minutes ago, jacobsaunders said:

I find it helpful to make myself a corner template, since all 8 corners should at least look related to each other. It would be quite enough to do that with some scissors and a square of old cornflake packet

And what shape would the template have?

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I almost always make antiqued instruments, but I never copy a worn corner directly. I "reconstruct" the corner on the drawing or photo to what it would have looked like in new, unworn condition, then make templates from that. Studying the corners on the instruments David suggested will give you an idea how the unworn corners should look. 

You'll need two templates, upper and lower corner. Extending them into the curves of the bouts is helpful to integrate the corners into the outline. And you need to pay attention to the angles of the ends of the corners when laying them out. 

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3 minutes ago, Nestorvass said:

And what shape would the template have?

It would be handy, since it’s your first violin, to have and old instrument lying on your bench for reference. Hold a corner onto an about 2cm x 2cm square cut from your cornflake packet, and draw around the fiddle corner with a pencil. Snip out

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4 minutes ago, jacobsaunders said:

It would be handy, since it’s your first violin, to have and old instrument lying on your bench for reference. Hold a corner onto an about 2cm x 2cm square cut from your cornflake packet, and draw around the fiddle corner with a pencil. Snip out

Well that would be ideal but also impossible for me. Aside from the fact that Greece is in lockdown right now I also don't know anyone who plays or owns a violin that I can borrow for reference. And even if I did I would still have to depend on the questionable skill of a luthier who I probably won't know. In any case thank you for the suggestion :)

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1/ Understand that Strad corners are drawn from sections of circles, right out to the end.

2/ Look at the Messiah and others, as David Burgess suggested, and try to break down what you see there. Look especially at the angle of the flat end relative to the curve coming from the c-bout, the length of that flat section at the end (usually 7-7.5mm, often larger on the bottom corner than the top). And the amount of hook on the c-bout side of that curve (how much does it close after the curve top or bottom?) Knowing that the angle at the end of the corner is usually about 30 degrees to the centerline , and also slightly sharper than 90 degrees to the inside curve will prevent you from hooking the inside of the corner too much or too little. 

3/ Once you think you have it, trace your rib corners on a piece of paper and try drawing corners around those tracings until you understand what you're doing and can see the differences. Use a circle template to make the lines, not freehand.

4/ Once you like what you are drawing, and understand it, do it in wood.

 

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52 minutes ago, Michael Darnton said:

1/ Understand that Strad corners are drawn from sections of circles, right out to the end.

2/ Look at the Messiah and others, as David Burgess suggested, and try to break down what you see there. Look especially at the angle of the flat end relative to the curve coming from the c-bout, the length of that flat section at the end (usually 7-7.5mm, often larger on the bottom corner than the top). And the amount of hook on the c-bout side of that curve (how much does it close after the curve top or bottom?) Knowing that the angle at the end of the corner is usually about 30 degrees to the centerline , and also slightly sharper than 90 degrees to the inside curve will prevent you from hooking the inside of the corner too much or too little. 

3/ Once you think you have it, trace your rib corners on a piece of paper and try drawing corners around those tracings until you understand what you're doing and can see the differences. Use a circle template to make the lines, not freehand.

4/ Once you like what you are drawing, and understand it, do it in wood.

 

Is that how you would want to teach someone how to make his very first violin?

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Yes it is. Good from the start rather than wrong from the start. My summer students over the years haven't had a problem with that.... people need to know what to do so that they can at least *try* to do it. That's what teaching does. If you don't do that for them, showing them what they need to do and providing steps to get them there, they are just wasting their first violin.

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To get an idea of how the use of circles adapts to the curves of the corners take a look at the images in this thread.

A simple circle, in my opinion, does not exactly reproduce the final curve of any corner, but it comes very close and is clearly the starting point, at least on a conceptual level. Then there is always the intervention of the maker's eye to make them more personal and less boring, even if these are minimal corrections they are significant for the final result. Relying on perfect geometry alone makes things, let's say, boring.

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Since I'm also a student violin maker, maybe I can help a bit, not using the geometric help of circles.

When I was making my first violin, the simple concept I was taught was that keeping the same edge-margin(from ribs) through all edge including corner is.. kinda boring. Rather It should be getting (very)slightly wider as it goes to the tip of the corner. It gradually widen outward, starting from the narrowest part of upper&lower bout and maintain its width across the edge of corner and decrease the same way at C-bout. However, it should be noticed that this difference is very subtle. Although I've never measured them the it seems to be only 0.5 ~ 1 mm, compared to the width of the margin of other parts.

I attach an image to help explanation..

KakaoTalk_20210123_024452699.thumb.jpg.ab0358db9167a2a83e764ebfa18e56ce.jpg

I don't know I explained okay but it's just a basic concept. But this concept and figures surely can be varied and as Davide Sora mentioned above, I always finish them and check with my own eyes how harmonious all 4 corners together are. I think it's important that they look aesthetically pleasing.

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The most important part of corner shape is the angle of the ends. When I was starting out I would  trace out the ribs onto the plates, pick points on the center line just inside the purfling at either end (which on a Strad is also the pin position). Then I'd draw a line outward through the center of each of the nearest corners to give a line bisecting the corner. Marking  the same distance as the planned overhang along that line gives a point which when connected to the original points at the end of the plates gives similar end lines for all 8  corners. From there you can draw the curves at the sides of the corners keeping in mind that whatever curves you use will continue all the way to the end line. Circles will stay circles and spirals will continue to spiral at the same rate right to the end and past it.

This process of determining the ends of the corners take considerably less time to do than it does to describe and while I now usually draw corners free hand If I am making a dead straight, non antiqued instrument I will still use it.

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I also use points on the center line to mark the corners,  as for the curve they widen a little but from the 2.5mm overhang in the bouts.   You can find pics in my thread.  Well, I'll post some here.  I have a pic somewhere if I can find it that shows the curves of an old violin closely match a specific type of oval.   

corners.jpg

platecorners.jpg

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30 minutes ago, Kyle Lee said:

Since I'm also a student violin maker, maybe I can help, not using the geometric help of circles.

When I was making my first violin, the simple concept I was taught was that keeping the same edge-margin(from ribs) through all edge including corner is.. kinda boring. Rather It should be getting (very)slightly wider as it goes to the tip of the corner. It gradually widen outward, starting from the narrowest part of upper&lower bout and maintain its width across the edge of corner and decrease the same way at C-bout. However, it should be noticed that this difference is very subtle. Although I've never measured them the it seems to be only 0.5 ~ 1 mm, compared to the width of the margin of other parts.

I attach an image to help explanation..

KakaoTalk_20210123_024452699.thumb.jpg.ab0358db9167a2a83e764ebfa18e56ce.jpg

I don't know I explained okay but it's just a basic concept. But this concept and figures surely can be varied and as Davide Sora mentioned above, I always finish them and check how harmonious all 4 corners together are. I think it's important that they look aesthetically pleasing.

This is correct but important to note that on many instruments the increased width is not symmetrical but rather occurs mostly on the C Bout side.

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1 minute ago, nathan slobodkin said:

This is correct but important to note that on many instruments the increased width is not symmetrical but rather occurs mostly on the C Bout side.

Yes! that was what I found out from lots of instruments. Thanks for pointing out!

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I went searching and found it.  An oval made by a three bar linkage... actually four bar but anyway...  It may not look like it in the picture but when I put the plate from an old German Strad copy on top of the drawing the curves of the oval exactly match the C bout curves.  Not saying a German Strad copy is a good example of a violin but it's all I had.  Amazingly one linkage makes both curves without changing it's position.  

cboutcurves.PNG

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11 hours ago, MikeC said:

I also use points on the center line to mark the corners,  as for the curve they widen a little but from the 2.5mm overhang in the bouts.   You can find pics in my thread.  Well, I'll post some here.  I have a pic somewhere if I can find it that shows the curves of an old violin closely match a specific type of oval.   

corners.jpg

platecorners.jpg

Thanks for the pictures. This is indeed the process I described.

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Just now, nathan slobodkin said:

Thanks for the pictures. This is indeed the process I described.

Sorry but couldnt edit the previous post. While the method shown in the photos is the one I referred to the corners drawn on the outlines look very stiff and unattractive  to me. I would say that the curves on the sides of the corners start to straighten toward the end rather than continuing to their logical conclusion.

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