Replies

1. 
   jerry | Oct 07, 2008 05:12pm | #1

   maybe something here
   http://www.lie-nielsen.com/catalog.php?cat=549
   at least for scribing the circumference.
   jerry

2. 
   Samson | Oct 07, 2008 05:30pm | #2

   How large will the circles be?  You might be able to use thin guage metal tubes of some kind with an edge sharpened to punch out circles.   Or something like this:

   http://www.garrettwade.com/hollow-punches/p/05s02.01/

   
   

   ---

   Edited 10/7/2008 10:42 am ET by Samson

1. 
   marguetry | Oct 07, 2008 06:35pm | #3

   I should have been clearer, the circles will be from 6" to 30" diameter.

1. 
   Samson | Oct 07, 2008 06:45pm | #4

   Okay, I've never done it, but I like to try to think about how I might, so here's a suggestion:

   - take a 3' x 3' piece of baltic ply thick enough to lie flat when set on a bench or table

   - use a router or forstner to let in a piece of magnetic metal roughly 2" in surface area near the center of the ply so that it is flush with the surface

   - lay your venner over this

   - secure the veneer with appropriate clamps at the edges

   - secure the center using the magnetic base of a dial caliper set, like this:

   View Image

   - now you can fasion an arm (or even use a string with a loop) to hold your knife the appropriate radius from this center pole

   - carefully cut your circle.

2. 
   WillGeorge | Oct 08, 2008 03:49am | #7

   Thanks for the link!

   I have to go look.. I 'think' I have a large set of Craftsman punches like that. Used for cutting engine gaskets as I recall? Have not seen them for years! I'm sure they are here someplace.

3. 
   md2453 | Oct 07, 2008 07:13pm | #5

   Marguetry:

   Get some scraps of 1/4 or 1/2" MDF cut them to rough size on your band saw then true them up with a simple circle jig on a disc sander and now you have very useful and low tech templates.

   Now using a scalpel or very sharp xacto knife follow the edge of the template and cut your circles.  I've done this on a number of occasions and it works beautifully and I didn't need to try to convince myself that I needed to buy another tool.

   Madison

4. 
   KeithNewton | Oct 07, 2008 08:25pm | #6

   The easiest thing that I have found, it to take a strip of softwood, about 1/8" x 3/4" by any length.

   Drill, or stab an awl through the pivot point, then stab or wiggle the point of a fine sharp blade through the strip at the chosen radius. If you use the same stick for cutting the circle and the groundwork, they will have the same arc, and fit perfectly.

   Going up and over, and back down like most trammel tools will not come close to being as accurate as this straight line approach.

   If you don't want a tiny hole in the middle of the circle. I tape a piece of 1/8" plywood to the center of the veneer, then stab it to swing the arc.

   If you use something like an exacto knife, don't try to cut all of the way through in one cut. It will try to follow the grain, which will lead to splitting down the grain. I usually sharpen a fine point on my pocket knife, which has a slight rounding back. This slight rounding back allows the leading part of the cut to be out ahead of the deepest part of the cut, and helps it to track better.

   Also, if the veneer has a tendency to split, crowd or stretch, it may help to cut down the slope for the keeper part, rather than where it is trying to work into the grain of the keeper part. This may not matter most of the time, but you will know when it does.

   I hope this helps. It is quick and easy to try. Of course you may feel cheated that you don't get to go buy another expensive tool. ha

5. 
   douglas2cats | Oct 08, 2008 04:15am | #8

   This would be similar to Keith Newton's reply except you'd get to buy a new tool:-)
   But I started thinking about my LV beam compass
   http://www.leevalley.com/wood/page.aspx?c=2&p=32629&cat=1,42936,42939
   and that if you ground a cutter from steel rod and inserted it into the pencil holding end of the beam compass, you'd have something that would work with the circle diameters you're after.

   If you build it he will come.