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Fix or forge ahead


Crimson0087
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13 hours ago, Crimson0087 said:

I think I need to learn some glue restraint....

Yup.

Glue doesn't stick well to varnish, so I varnish the mold where sticking might be a problem.

My finished linings are 1.7 x 7, and maybe a mm or so taller to start with.  2mm spruce I find a bit hard to bend.  Maybe fresh spruce would bend better, but I use old stuff.

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So I think it's important to discuss this a little bit more in detail as to why it's a good idea to forge ahead...

something tells me that you are concerned about this because your thinking that this small gap could be one of those "nightmare stories" you hear about that "buzz" that could not be found....thinking that perhaps under certain circumstances of vibration that somehow the wood will start rubbing together like cricket wings, but, based on the location, an area prone to not vibrating much, I don't think you need to worry about it.

As mentioned by Christopher, I would suggest padding/protecting the rib side, using a strong appropriate sized clamp, to attach the clamp first, and feed a little water in their repeatedly over the course of a half hour or so and then "open/ close" the clamp repeatedly for a moment to see if you can not close it.

after dry if there is a wee gap, this is a case where "glue" is filler...as we here "glue is not filler" but in this case it would be fine to load it up with a toothpick...

again this is a "nodal region" and just does not see lots of "hyper flapping" that would lead to buzzes

We want to be anal retentive where it counts, I think it is easy to get too much so over the entire project and it just kills intuitions

If ever "use the force" was applicable in real life, it's in building instruments

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On 9/23/2022 at 1:36 AM, Crimson0087 said:

This is the wood I used for linings...they are 2mm thick spruce. Also here's the ribs out of mold. I think I need to learn some glue restraint.....gobs of glue everywhere.....anyone out tape on mold to keep ribs from sticking? Got tape stuck everywhere too..

In addition to varnishing the form (I use just shellac) as Don Noon suggests, I apply paraffin or soap every time before gluing the ribs on all surfaces where the glue could run.

https://youtu.be/O6BiP-yejVQ?t=36

1.8 / 2.0mm is fine for linings thickness, 7.0 / 7.5mm for finished height. I cut them to about 8,0mm before bending them

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Thanks Davide. I have another question. Do you have any tips during the arching process. I feel its easy to carve it to match the arch template I am using at and around the area where I hold the template but then Blending the areas between seems tricky. Im sure this is something that comes with practice but are there any tips you have or things that maybe you realized and were like "Aha this makes it easier"? 

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9 hours ago, Crimson0087 said:

Thanks Davide. I have another question. Do you have any tips during the arching process. I feel its easy to carve it to match the arch template I am using at and around the area where I hold the template but then Blending the areas between seems tricky. Im sure this is something that comes with practice but are there any tips you have or things that maybe you realized and were like "Aha this makes it easier"? 

I can't help you much, because the difficulty of blending the various crossarches together is precisely the reason why I don't use them. For me it is essential to develop a 3D perception of the entire arching, rather than focusing on individual crossarches. A suggestion could be to make the cross arches higher by at least half a millimeter than the final shape, blend everything and see how it comes out, then proceed by scraping all the arching to bring it to the final shape you like, using your templates only to check if they match. This helps to develop a vision of the whole that I consider essential to have a control of the arching shape, and also to speed up the work once you have it. Of course, looking at the largest number of original archings (ancient or modern), by looking at them trying to figure them out from the same point of view you have when you work, will go a long way in developing this sense of 3D perception of the distribution of arching volumes.

To check the shape I do not use fixed templates because they are too binding and they oblige to always repeat the same arching, which never happens. I prefer to use a variable template, i.e. not a template:)

 

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1 hour ago, Crimson0087 said:

I've seen people use drill press for thickness the inside. Wonder if anyone uses a similar method for the top. Set the depth and drill holes around the plate and carve till they are gone....

It's a possibility, and I suppose someone does, but for me it's a useless waste of time, it would be extremely slower than roughing by eye, if your eye and hand are trained. I see it more as an amateur thing for those who don't trust their eyes, but honestly at that point it would be more profitable to get a CNC:)

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1 hour ago, Don Noon said:

I find that a marking thickness caliper like the one below is handy for visualizing asymmetries and kinks in the flow of the arching.

Yes, I forgot to mention this, I also use thickness calipers to trace isolines. I don't have one as beautiful as the one Don showed, but five self-made and always kept at the same measurements, to save time and be able to repeat the same measurement several times without wasting time in adjusting.:)

1371972405_Thicknesscalipersrid.thumb.jpg.f67c5851ebb1b96102d2de61911df60e.jpg

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8 hours ago, Crimson0087 said:

I've seen people use drill press for thickness the inside. Wonder if anyone uses a similar method for the top. Set the depth and drill holes around the plate and carve till they are gone....

That's part of how I work, in fact. You can see some discussion of it on my Instagram. The short version, without images:

After sawing the outline and setting the width of the channel in each bout, I depth drill several points along the center line to define the long arch.

I carve in the long arch, beginning with a scrub plane and finishing with a small block.

I mark the locations for the depth drill marks of the cross arching at several locations, more or less dividing the long arch into 9ths. The heights of the marks come from a recursive geometric scheme devised from CT scans of original instruments, corrected for distortion. Using the drill press and a tapering gauge as before, I drill the holes 

Using a gouge and then finger planes, I carve the cross arching, following the guide marks I drilled, essentially connecting the dots. I carve large areas at a time, which for me at least makes it easy to avoid lumps or hollows, until the marks are just barely still visible.

Using gouges of the selected sweep and width, I carve the channel to depth.

Lastly, I return to finger planes to blend the arch into the channel, then scrape. All done. 

I made my first violin with templates, and found it rather cumbersome, restrictive (your templates are made to a set height, whereas the simple math used to derive the control points can be modified at will to accommodate wood properties), and slow. But I find this quite quick. 

 

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6 hours ago, Davide Sora said:

It's a possibility, and I suppose someone does, but for me it's a useless waste of time, it would be extremely slower than roughing by eye, if your eye and hand are trained. I see it more as an amateur thing for those who don't trust their eyes, but honestly at that point it would be more profitable to get a CNC:)

Despite doing it the way I said, I do agree with Davide here, and more and more I prepare fewer and fewer control points, which speeds things up a lot. I feel that as time goes on, I'll be able to leave it entirely to eye as he does. I do appreciate the way that working like this has helped me develop my hands to make the shapes my eye, and my minds eye, see. 

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7 hours ago, Davide Sora said:

I see it more as an amateur thing for those who don't trust their eyes, but honestly at that point it would be more profitable to get a CNC:)

I realize this was in jest, but "profitable" and "CNC" only might go together for those who are technerds, going into mass production, and have a good market for the piles of product.  Otherwise, it's more of a costly, time-consuming hobby.

19 minutes ago, JacksonMaberry said:

Despite doing it the way I said, I do agree with Davide here, and more and more I prepare fewer and fewer control points, which speeds things up a lot. I feel that as time goes on, I'll be able to leave it entirely to eye as he does. I do appreciate the way that working like this has helped me develop my hands to make the shapes my eye, and my minds eye, see. 

Not to be lost here is the need to get the mind's eye to know what shape is the goal ... by getting your hands on as many great instruments as possible, and studying them.  Templates and practice leave a lot of gaps.

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25 minutes ago, Don Noon said:

Not to be lost here is the need to get the mind's eye to know what shape is the goal ... by getting your hands on as many great instruments as possible, and studying them.  Templates and practice leave a lot of gaps.

That's good advice for our friend here, of course. I hope he'll be as lucky as I have been in getting to hold onto fancy fiddles for a while. 

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12 hours ago, JacksonMaberry said:

Despite doing it the way I said, I do agree with Davide here, and more and more I prepare fewer and fewer control points, which speeds things up a lot. I feel that as time goes on, I'll be able to leave it entirely to eye as he does. I do appreciate the way that working like this has helped me develop my hands to make the shapes my eye, and my minds eye, see. 

I hope my definition of amateur was not offensive, it probably would have been better to write "in the learning phase". In fact, I believe it is useful and also essential, during this phase, to refer to pre-established measures to help get to the point and educate the eye, then with time and progress you will come to a point where you will realize that following pre-established measures will become just a waste of time and essentially superfluous. It is a natural evolution that each of us has gone through.

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4 hours ago, Davide Sora said:

I hope my definition of amateur was not offensive, it probably would have been better to write "in the learning phase". In fact, I believe it is useful and also essential, during this phase, to refer to pre-established measures to help get to the point and educate the eye, then with time and progress you will come to a point where you will realize that following pre-established measures will become just a waste of time and essentially superfluous. It is a natural evolution that each of us has gone through.

Not offended in the least. I agree very much here. 

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