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catnip

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  1. Before we start the bend the C bouts I raise the C blocks with a 2 mm spacer. I used to use double sided tape but I find tacking it with 23 g brad pin much more convenient. I have been using a leather bending strap but for this highly flamed maple I will be using a brass bending strap. There are advantages and disadvantage with leather. Here is a simple way to make a bending strap using 0.15" by 3" by 15" brass shim stock. Just split 3/4" pine handles in half. Sandwich and glue the brass between pine handles reinforced with 1/8" dowels. Then I added 1/2 round molding to each side for a better finger grip.
  2. I use a squared edge scrapper to finalize the thickness of the ribs to ~ 1.1 - 1.2 mm, maybe a little thinner for the C ribs because it is easier to bend them without cracking. I find that turning a scrapper edge twice gives a more aggressive cut. Lower ribs are cut to ~220 mm, C bouts to 135 mm and Upper bouts to 180 mm.. Because of the slight flame angle the ribs will have an orientation of either forward slanting or backward slanting. Once the orientation is determined labeling the ribs with block numbers helps me prevent inadvertently bending them the wrong way.
  3. Now it is time to cut the ribs. From the original one piece maple billet ~ 20 mm thick I was able to cut tapered wedges from the center line to an approx ~ 8 mm edge for the length of the billet. These ribs will precisely match the back flame. I also like to identify the order in which the ribs were cut so that I can easily book match the lower ribs at the bottom from the sequential cut. I use a very simple jig to bring the ribs to a workable thickness before finishing them with a scrapper. It consists of a squared 2" x 6" board with a small 1" board added to it. This is the top view. I just mount this jig on my oscillating sander and secure it with large C clamps at each end. With the left end secure I can adjust (nudge) the right end each time. It is simple and works very well for me. The 1" offset allows me to grab the rib with my right hand as it is being pushed by my left hand.
  4. Flat sand the bottom of the blocks and repeat the same procedure for the top of the blocks. Leave the blocks slightly proud as there will be more flat sanding after the ribs are glued and after the linings are installed. Use the template to draw the outline. First, I use a bandsaw (3/16" thin blade) to rough cut the outline of the blocks then finish up with an oscillating sander to profile the corner blocks exactly to the pencil line.
  5. Collapsible molds are not necessary; I just find them a bit more convenient. Traditional ½” plywood molds are far more common but require more care in choosing corner blocks (grain orientation etc..) and removing the garland after the linings are in can be a bit challenging before you get the hang of it. I prepare all my blocks ahead of time and label the height (and also density) so that it just a simple matter to select them from ~33 mm end block tapering to a ~ 31 mm for the top block. I also use a sanding board to adjust each block to a good fit. A small tab of fish glue is applied and then a F clamp (or C clamp) is used. The collapsible mold is raised by two ~ 9 mm wooden spacers before gluing all the blocks. I prefer a wider bottom block which I taper afterwards to blend into the ribs. This will become clear afterwards. This gives a bit more support to the chin rest.
  6. Here is the assembled form showing the outline and the areas to be cut out. But first we need to align the template using the center line and a horizontal line in order to drill the upper and lower location holes. Temporarily double tape the template to one side with the alignment pins and trim that side of the form using trim bit router. Repeat for the other side. Disassemble the mold to check both sides for symmetry with the alignment pins then cut out the shades areas. Also cut out the shaded area for the upper and lower blocks. Reassemble the mold and apply several coats of varnish (shellac).
  7. It is the start of a new year and I am reviewing my method of making violins. This build may be a bit more detailed as I trying to help some of my novice luthier friends with their build(s). Also this is my mid-century build and it is time to reflect. To start, I usually use a full-size photocopy of a Strad poster for the outline but this time I will use a Maestronet resource Keisler pdf supplied by HoGo. It is sized for A3 paper but Adobe can print it to multiple pages in Poster Mode (100% scaling). Then I used my light box to line up and tape the two pages using only the right half. I glued it to 1/4" baltic plywood using a spray adhesive, then trimmed it roughly to the outline. I do not make exact copies so there is some flexibility to make some minor adjustments to the outline based on my preferences. I am now using 12.5 mm (1/2") generic collapsible molds which can be easily customized to any template. The essential idea (trick) here is using an 1/8" (3mm) x 1/2" (13 mm) slot cutter for the grove. The removable upper and lower spacers are also made this way except I glue ~30 mm wide tongue in the groove and adjust the width so it fits tightly (wax also helps). Here are the pieces of this mold showing where I drilled the holes for my 10 - 24 x 1/2" Robertson screws. I just use a 10 x 24 tap for the lower hole and harden it with thin crazy glue afterwards. Use a 7/64 drill for initial hole then enlarge just the upper hole and spacer hole to 3/16".
  8. My brother has been doing portraits all his life and said that he had a lot of difficulty including a violin in one of his paintings because he never "looked" closely at violins . His copying skills from portrait photos is excellent but the violin has a lot of "extra" features he was not aware of.
  9. What is the benefit of using spruce over willow? I have willow ranging from 0.33 - 0.38 gm/cc which is in the same ball park as spruce and willow bends so easily. I pre-cut my willow linings to lengths (3 sizes for Upper, C, and lower bouts) plus 1 cm. Then pre-bend to shape to for at least 5 violins. Store in labelled plastic bags for when I need them. It means when I do linings I only need the glue pot.
  10. I tried to make my own TO using his recipe and it did not behave as well the the real Tru-oil. I buy my Tru-oil from Lee Valley and do not remove the original seal. I just prick the seal with a pin so that I can control the output by drops and the hole is so small so it lets in very little air.
  11. Here is something that may be of interest. oud maker He claims that Tru-oil is essentially 56% mineral spirits, 33 oil varnish (alkyd resin) and 11% linseed oil. I have used it as a final rubbing "polish" on a few instruments by diluting it 50% TO + 50 % mineral spirits using a very fine cotton polishing pad. This dilution is to avoid the very fine "streaking" that a pad can leave behind. Also it helps the leveling out. I do not over rub as its dries quickly and I use cut lighting to see the leveling just after the rub. It just one of many ways of finishing.
  12. The width of the neck at the nut is 24 mm. I off-set the E string by 4 mm from the edge of the fingerboard and the G string by 3.5 mm with two pin pricks. Then I divide the distance equally into 3. Before I cut the grooves I draw in the string lines as a visual guide for my little veneer saw. I finish the groove with a Japanese file. I use a similar method for the bridge but with equal off-sets.
  13. Thanks for identifying the wood. I bought this billet in June 2010 and I am not sure where I got it ... maybe Exotic Woods. I was able to re-saw the billet into 3 pieces around ~19 mm thick and they have been air drying since then. To set the neck I use a white center line and a temporary bridge to check the alignment just before I glue it. I also have a corked lined top caul with a countersunk 4 mm deep hole which makes clamping much easier.
  14. This one piece maple is a bit unusual since the flame is very narrow and perpendicular to the grain (no slant). I had to search my stock to find a neck with a similar pattern. Here is the enclosed body before I set the neck. As per usual I have left the graduations a tad (+0.1 mm) on the high side so that I can finish any anomalies on the outside. Before gluing the label I frame the area with tape and size that area with hide glue before gluing the label.
  15. I have made a 6 mm fingerboard template that is slightly oversized by 0.5 mm. When I get new fingerboards I use double sided tape to attach the fingerboard to the template and then I use a router to trim to the outline. Then pencil mark the bottom, flat sand, date and store. This method has worked well for me. Here is a picture of the top of the fingerboard.
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