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After the plate has dried, check the bottom side with your straightedge. If the bottom is uneven, you will have to plane it perfectly flat so that the ribs are in full contact with it.
  1. Remove all excess glue and clamp the plate down on your workbench. If you have a workbench with dogs, use those to fix the plate upside down. Or you can use sash clamps to hold the plate and clamp the sash clamps down to your workbench.
  2. Make the bottom perfectly flat using your long plane. Be careful of the wood grain. The two billets' grain runs in opposite directions so you will need to keep flipping the plate frequently to go with the grain to avoid tearing. (tearing is more likely with highly flamed maple) Tilting the plane sideways a little or going accross the grain should help too. If nothing helps, use the scraper blade.
  3. To remove little tearing caused by planing and achieve perfect flatness, you can sand the bottom on your flat sandpaper glass surface (you used this to finalize the rib height).

Fixing the ribs to the plate

Now you need to fix the ribs to the plate in order to transfer the actual outline. If at this point you are also transfering the outline to the back plate, do not forget to include the button. See the Back chapter for its dimensions.
  1. On the ribs, remark the centerline, if necessary.
  2. Take the ribs and put them on the front plate. Align the centerline on the ribs with that on the front plate. See Fig. 1.
  3. Mark out the very top and bottom of the ribs, drawing a 1 cm long line, at the centerline of the plate. See points "A and B" in Fig. 1.
  4. Remove the ribs and on the centerline of the top plate, scribe another pair of marks, about 4 mm inwards from the top and bottom marks "A and B" you have just made. See Fig. 2. The red dashed line just shows for illustration where the ribs were placed.
  5. At those two points, drill through two holes, 1.5 mm in diameter, at right angles to the plate.
  6. Put the ribs back on the front plate in exactly the same position as before {par. 2}, clamp down sufficiently and drill two 5 mm deep holes into the top and bottom rib blocks using the previously predrilled holes as guides.
  7. You can now plug into the holes two 1.5 mm drill bits as locating pins to keep the ribs positioned on the plate. With the bits in place, you can remove the clamps and start with the outline.

Marking the outline

Make sure the outline of the ribs is flawless, the corners are finished.
  1. Using a sharp scribe, mark the whole outline of the ribs on the plate. Make sure you also mark distinctly the ends of the ribs at the corners, but don't make the mark too deep as this will stay on the finished plate. See "A" in Fig. 3.
  2. Now you need to draw the second outline which will delimit the shape of the top plate and which should be outset by about 2.5 mm from the ribs, depending on the overhang on the original violin. For this choose a washer, which you know will offset the contour by the distance needed. Using a sharp pencil draw this parallel line around the ribs, but always stop about 1 cm short of the tips of the corners. See "B" in Fig. 3.

    Make sure you hold the pencil at a constant angle as different angles may produce different distances. Make a couple of tests, to get the idea as to what kind of line the washer and the pencil produce.
  3. Remove the locating pins and take the ribs off the plate.

Category: Front