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Torbjörn Zethelius

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Everything posted by Torbjörn Zethelius

  1. quote: Originally posted by: Jon Gundry Hello all. I am long time lurker and this topic has gotten me to take the plunge and finally post. Torbjorn, I very much enjoyed the Strad article but there are a few things that I am not quite clear about concerning this technique. Here are my questions: 1. Do you also establish the longitudinal arch down the center spine of the plate with a chain as well? or do you only do the two diagonal and 3 horizontal checks with the chain and just blend the rest? Or do you use the chain for every diagonal variation from left to right as if there is a pivot point at the lowest point of the overturned plate (I hope this makes sense). As well do you check every horizontal curve with the chain or just the three horizontal points and do the rest by feel? 2. Once this central rectangle is established on the inside of the arch it appears that you scribe a line at the point that the recurve would start to rise above the outside edge of the finished plate and then you reestablish the inside longitudinal arch with the chain at the widest points of the upper and lower bouts and then blend this back into the central rectangle. Am I correct with the method and sequence? 3. Finally do you then carve the low point of the recurve on the outside, and then spike the outside of the plate to establish the graduation? And that any difference in the outside appearance between top and back plates will be due solely to the different graduations maps of the top and back? I apologize for making my first post such a whopper but I really would like to give your method a try and want to make sure I have the all of the particulars down before I start. Hi Jon, I'm glad you liked the article. I was thinking that maybe I should start a special thread dedicated to FAQ's re: the inside first method, practical work ('how to') questions. 1. The curve along the center seam is not a catenary. It is made up of the diagonal catenaries and the cross catenaries. The main points where the chain is hung is along the red lines in the layout scheme. The rest can be worked 'by feel'. When in doubt, consult the chain. 2. I am not quite sure what you're asking here. The recurve doesn't rise, it lies flat. The catenary flattens out towards the ribs. At least as long as we're looking at the inside. Alt. 2. Or, if you're asking about the making of the long arch. I start with what I call the 'loaf', the central part. When I'm near finished with the diagonal catenaries, I start working on the cross catenaries across the widest part of the bouts. I 'fuse' them together. I.e. none of the curves should distort the others. 3. I finish most of the thickness in the arch, and then I start working on the recurve, and edges. Yes, it is my impression that the difference in outside arch shapes are due mostly to different graduation schemes of back and belly. Hope this helps. I'm not sure that I understood your questions correctly. It is really quite straightforward once you start working from the inside.
  2. It is my Cremonese ruler, made from a piece of rib. The Roman numerals indicates Cremonese oncie. I don't want to go into this in detail because it's a different topic. I choose the wooden ruler because it looks nicer in the photo than a metal one. It is used solely as a straight edge here, nothing else.
  3. quote: Originally posted by: NewNewbie Thank You for the pictures of the Spike, they have been most helpful. Do you have any others? No, I don't. I'm posting a couple others of the inside work procedure though. Enjoy.
  4. quote: Originally posted by: NewNewbie In this picture ( http://img247.imageshack.us/img247/2943/270gr5.jpg ) I see something to the left of the main spike unit. Is it a small nail? It seems to cast a shadow? Hard to tell with all the black. If it is then perhaps a movable spike became useless and was made to be immovable with a nail? You nailed it. That's very observant.
  5. quote: Originally posted by: NewNewbie I wonder if the channel in the thicknessing spike of Stradivari's was a failed device? I have a few of them in the shop! I say this because if that threaded spike had been moved to another location then it would leave marks in the wood, from the side screw being tightened, but I didn't see any in the close-up picture. Perhaps the anvil gauge was used for the cello extremes instead? Stradivari's thicknessing spike might have been a highly specialized tool, serving several different purposes. That could be an explanation/excuse for the movable spike. But you could also speculate that it was made with spare parts from some other device. Then it's not neccessary that the movable part of the spike serves a real purpose. FWIW, the iron also adds weight. <-------!!------>Most people tend to think of it as a tool that is fastened to the work bench. However, the small size of it suggests that it could have been held in the hands while the work piece instead was being fastened. If it was huge, like a cello plate for example.
  6. quote: Originally posted by: magnus nedregard At least this theory is supported by the general agreement that Strad introduced some changes to the Cremonese method and style. Look at an Andrea Amati and a Giuseppe "filius" Guarneri. They are not that different despite they're distant in time. Look at a post-1700 Strad beside the same Guarneri and the difference is enormous. Strad must have been the most innovative maker since Andrea Amati, and the absence of the dorsal indicates some change in the graduation/arching system. Stradivari was very inventive, but my feeling is that he worked very close to the tradition of Andrea Amati. His arching style is a continuation within the classic Cremonese style. His Long pattern violins (ca1690-1699) can be understood from the perspective of the inside long arch 'organ pipe' line of thinking. (Referring back to my article in the Strad again.)
  7. http://darntonviolins.com/ethan/markribs1.jpg Is it possible that moving the spike allowed the spike to reach some of the "hard to reach" areas of a cello? his way you could use one thicknessing spike for both violin, viola, and cello. Spike size listed as 382 mm x 108 mm. I have thought about it, but the support peg is immovable. So I don't know. I'm testing again... BTW I gotta go now. See y'all later.
  8. ok, this is a test... no photo. Where did it go?
  9. quote: Originally posted by: NewNewbie "The space for photos was limited. I hope to have some more photos up in a different location on the internet soon." ============= Can you post them here? No limit to the space. You just use the section at the bottom called *Attachments:* and browse your hard drive to load them. Click on * Attach File(s) *. It would be considered torture to make us wait!!! ok, this is a test... It was impossible to shoot the photo and hold the chain, so I just laid it down. You have to imagine my fingers holding it at the ends, it is the same curve either way.
  10. quote: Originally posted by: NewNewbie One thing that would have helped the article in The Strad magazine more, would have been a picture of you holding the chain *diagonally* across the plates, instead we got two of the same pictures of you holding the chain crosswise in the middle bouts. Was this an editing mistake? I take it that holding the chain *diagonally* across the plates lead to the outside " Loaf " look as the end result. It is this " Loaf " look that is missing from the outside arch first approach. =========== " Beethoven had an ear for music. Van Gogh had an ear for art in general. " Wasn't Van Gogh's ear for his girlfriend? The space for photos was limited. I hope to have some more photos up in a different location on the internet soon.
  11. quote: Originally posted by: ctviolin Beethoven had an ear for music. Van Gogh had an ear for art in general. guffaw! Craig, I adopted it from you. Thanks.
  12. quote: Originally posted by: NewNewbie "Welcome Torbjorn, it is so nice to see you here! Craig T" ==================== First let me also join Craig by saying Welcome ! Please also let me say Thank You for your article in The Strad as well. I enjoyed it . Are there anymore pictures of the thicknessing spike? I was hoping for different views. Is the picture from a web-page? The thing that struck me from the long range, full view of the thicknessing spike ( middle of page 45 of the Aug Strad ) is; that it looks as though the tip of the spike ( if the spike was fully screwed in ), and the rounded dome , both meet in the center, between the base and the mobile arm. The other thing that strikes me about the picture of the thicknessing spike, that you just posted is that the spike itself is in a channel, which could mean that this tool was used in more than one mode. Their is a locking thumb screw that would allow the threaded spike to be re-located on the arm to another position , very quickly. I would think that it would be most interesting if an *exact* working replicas of this tool could be made and used. I am sure new in-sites might be gained. Thanks. I have had the same thought myself. There is a lot of things to be learned just from studying Stradivaris' tools. If we could put them to use, there would be even more things to learn. Craig, good luck with your new plate.
  13. quote: Originally posted by: magnus nedregard Hi Torbjørn, great article! Hi Magnus. Thank you.
  14. quote: Originally posted by: Michael Darnton A point of agreement! We seem to have the same feeling about each other! But we're not quite equal: you're heavily invested in your idea; I'm only invested in the idea of evidence. So you're denying that there are peg marks on the outsides of instruments, then? I haven't denied anything yet except the validity of the logical process that leads to your conclusions. Michael, the 'inside first' method works for me. That's the only reason why I believe in it. I couldn't make better arches from the outside, as I say in the article. I am not denying anything, but I would expect the peg marks to look different from the ones in your photos, when comparing them with the graduation spike. I would love to learn yet another way to make Cremonese style arches.
  15. quote: Originally posted by: Michael Darnton Torbjorn, I'm unclear about what marks your saying are where on Strads? I know that there are pinpricks on the outside in a number of specific locations--not randomly placed--that must have been for some sort of layout process, not graduation, but I'm not aware of others that are just all over the place. They are randomly placed as well as in specific locations. I could point them out to you if we were in the same room with the real thing. You would see the pin pricks, but would you be convinced? I doubt it.
  16. quote: Originally posted by: Michael Darnton I've seen them on other Strads as well, so if you have an alternate suggestion, I'm up for it. Otherwise, your comment would be a like me saying "I think the marks in your photo on the Grancino cello aren't pinpricks from a graduating punch", without providing any more insight. "Thinking" is OK, but evidence is best. Ok, try to match http://darntonviolins.com/images2/dimples.jpg with http://img247.imageshack.us/img247/2943/270gr5.jpg (Sorry folks, I don't know how to make the images visible.) I'd say it's up to you to show that the dents come from the graduation spike. I don't see how they could.
  17. quote: Originally posted by: Michael Darnton I'm quite prepared to accept that some makers of the past have worked from the inside out, when there is evidence to show that, and where contradictory evidence doesn't exist. In Stradivari's case, and about Cremonese method in general, I don't see either requirement of that standard has been met. That's a progress. Take about any Strad, and you will find the marks in the belly from the graduation punch. There are plenty of evidence. There are a few instruments where I haven't been able to spot the marks for certain, and they have been Strads. But four out of five Strads have them. -------------- I didn't say that Grancino made his arches as in the Trade Secrets section. What I'm showing there is a way to make Cremonese style arches. If you try it, you may find it beneficial.
  18. Thank you, Craig. It's nice to be here.
  19. quote: Originally posted by: Michael Darnton Of course you do, but if Stradivari had thought the same way, we wouldn't have the photos, above, would we? But we do. Assuming that they are what you say. But I don't think that's what they are though, as I said before.
  20. I try to avoid to make dents. They'd distort the inside arch, and make the graduating less reliable. I would expect that Stradivari would do the same. Also, it's only under varnish that the dents would be visible, I guess.
  21. Hi all, I have been following the debate on Maestronet with interest, naturally. Since I upgraded my browser I can actually participate. :-) I can't see that these dents in Michael's photo: http://darntonviolins.com/images2/dimples.jpg could have been made with this tool: http://img247.imageshack.us/img247/2943/270gr5.jpg The tip of the supporting peg is round (of course). It doesn't look anything like the dents. I don't know what made the dents, but it wasn't Stradivaris' thickness punch. Best regards, Torbjörn
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