January 2006 (2):
The weekend of January 21, we put our
mind to completing the plywood base of the southwest finger table staging level.
Originally we had in mind a hexagonal table section, but in the final analysis,
a radius curve looks better and is more functional.
We quickly determined to use a method we
have seen several times on the
New Yankee Workshop. The method involves use of a jig that holds a
router and pivots on a 1/4' dowel at the center point of the radius. First
step, is to find the center of the curve. While there was a bit of trial
and error, it all starts with measuring the two points of the curve that are
furthest apart. This distance was 66 inches, giving us a 33 inch radius.
We then marked that point on the plywood top and made a second measurement from
the front edge of the table 33 inches back.
We then had to build the jig. We used
3/8" press board and 5/8" plywood to build the jig. You might ask why
those two products, simple, they were scraps laying on the floor. The
press board spanned the 33 inches we needed and the plywood provided some extra
strength. You attach the router by removing the base plate, then marking
and drilling holes in the jig. Be sure to recess the screws so there is a
smooth base in all cases. We attached the router, plunged the 5/8"
straight cutting bit through the base and then measured back 33 inches to find
the center point.
Once built, we drilled 1/4" holes in the
jig and the table top to form the pivot point. We then made a test run and
we found we had some clearance problems with the 4x4 post. So we notched
the jig to allow the extra swing necessary to complete the radius. You
will also note that we used a
dremel tool to cut off the excess of the screws used in building the jig, we
do this in all cases for safety. Here are the pics that show you how we
put this all together (My apologies to Norm Abram for the lack of clean
lines on the jig, but it's functional and that's all that matters):

Here are pics of the final product.
You will see we have cut pieces to fill the gaps in all cases except the space
that runs the length of the outer table. When we put the main piece in
place, we found that a scrap we had from another cut nearly fit perfect.
Rather than waste another cut, we decided that once the homosote is laid on top,
this small gap will be inconsequential. We placed the outer edge at its
best fit, then ran the screws and were set for the cut.
Before and
After.....

Other Updates:
2008
2007
2006
2005