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Hello all i've just got the Benedetto book and can't figure out how to transfer the arch heights from the templates to the top/back so you end up with the drilling contour map shown in the book, any help appreciated Thanks Roby.

When carving with templates, make the templates 1/4" thick (hardboard or whatever) Rub pencil lead along the inside edge. Then rub the template over the developing arch & remove the highpoints the template has marked.

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Dave
Milton, ON

I use the templates in the book to work out the top. On the outside I don't drill... I plane, grind and sand to get the contours right for the external plate. For the inside I setup a pin on my drill press and a depth stop on the drill depth to follow the outside contour. Drill a bunch of depth gage holes ( I set mine to leave the plate at 1/4 inch) and then I grind away the inside which then matches the outside. I think this concept is covered in the book. Works for me....

One simplified way is to first draw out your concentric shapes as per Benedetto on the joined top or back. You then mark the spacing of those shapes onto your template. Now either lay the template flat on a piece of paper and register the outside bottom edge of the template against the line and the middle of the template 1" above the line (or whatever your arch height is if it's not the same as Benedetto's) or stand it on a benchtop and measure from the benchtop to the template at each of the marks you've made indicating the positions of your concentric shapes. If doing it flat on paper, just measure from the straight line drawn on the paper to each of the marks you've made on the template indicating the positions of the concentric circles you've drawn on the top or back. This will give you the distance from the drill press table to the tip of your drill bit. The depth of the holes should be constant on each of the circles. Leave some extra wood (I leave 1/16" to 1/8") to allow for final carving and tweaking to match the templates. Easier to do than explain.

That's a great idea Dave!
I've had pretty good luck with the method Mottola described ( http://liutaiomottola.com/BookTips/benedetto.htm) just download the PDF. I had the outlines copied at the different percentages he describes. Made a jig to rout the steps and did the rough work with a sandpaper flap disk on a die grinder.



Makes a hell of a mess.
Have any of you guys used an arbortech blade on your grinder?

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Thanks for the article Terence. I do it similar to many using a safety planer to cut the steps. The top is pretty fast using hand tools for carving. For the back, I help things along using a Kutzall disc and a 40 grit disc on a mini grinder (outside of course, mega dust). I'd like to try the arbortech sometime, but the Kutzall definitely works well and is easy to control.

Yo, Robin,
These are all worthwhile, good solutions. But I'll tell you for sure: You would be amazed how quickly it goes of you just start making shavings, front to back. If you do this, establish your perimeter thickness first--all around the edges of your plate. Just mark it with a pencil or scribe line, as Benedetto demonstrates. Then, check frequently with your main template, always along the center line. When you are in the neighborhood, begin to employ your side templates. Do this with a strong raking light pretty frequently so you can see the high and low points under your templates. In a relatively short period of time, you will have it. I promise you, it probably doesn't take any more time than drilling or saf-T-plaining ledges in your top (and cleaning up with planes), and it's fun to make shavings from the start.

But there's nothing wrong with these other methods and many builders use them. It suits their methods of work and that's great. I just happen to be one of those who would rather make shaving than turn on a power tool whenever I can avoid the latter.

One other thing, and this might be important to you: Benedetto's templates include the scooped out recurve shape. Many builders find it helpful to cut or sand those recurves off
the bottom edge of the templates and carve to the "edge ledge." The recurve can be scraped out later.

Patrick

Thanks Terrence..... standard approach for me, especially when doing a new shape or arching. I'll start by planning the longitudinal arching, then use that for measuring centerline height at the various stations where I want a transverse template (which I then generate as a cycloid). Patrick makes a good point re altering templates to "bottom" on the ledge at the correct arch height. Another thing is to use full width, symetrical templates rather than half patterns. When you have full contact & both edges touch, your there! You're left with a series of troughs across the blank, which you can rough fair with power tools or do completely by hand (which is actually kind of fun).

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Dave
Milton, ON

Thanks for all the great suggestions guys as allways this place has helped me no end.This is gonna be my first attempt at an archtop one more thing would it be possible to scale the templates down to make a smaller body if so would you reduce the height of the arch allso,thanks again everyone Roby

Some good info guys! For the die grinder/sander/router crowd, have you come up with any kind of dust collection that actually works? I usually wind up doing it outside.

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It's not what you don't know that hurts you, it's what you do know that's wrong.