Raised Panels on the Table Saw
When it comes to methods and techniques of doing processes on traditional tools, there really is not a whole lot "new". If you go back and look at the woodworking mags of years ago, you will find the same "tricks" that you see in the mags of today. The monthly winner of one magazine's tips and tricks column recently won for a tip on matching up the hinges for the lid of a small wooden box. His tip was to locate and drill the holes into the top edge of the back of the box, then glue the lid on. Once the glue set, he cut the top off a short distance below the glue line, including part of the sides in what is now the lid. This serves two purposes, 1) it braces the lid with long grain perpindicular to the end grain on the lid preventing warp, and 2) the predrilled holes for the barrel hinges are now in both the new lid and in the back, perfectly aligned since what was once two holes is now four. Neat trick, but not new. An old timer told me that trick a long time ago.
Another old trick that I was reminded of by the recent republishing of articles from the old "Deltagram" involved the cutting of coves on the table saw. I had seen this tip before, but, like so many things, it had gotten misfiled somewhere in the back of my mind. I got to thinking about this idea when I was needing to cut some raised panels for a project. Not having a variable speed router to stick one of those gigantic panel bits into, and not really wanting to spend the bucks for a new router, I was thinking of either cutting them vertically on the table saw, or getting one of the those vertical panel bits for the router. I don't find the straight line cuts on the table saw really attractive, I wanted something with some curve to it. If I could cut a semicircle or other cove on the table saw, why couldn't I do half of one in the same manner. Gave it a shot on a smaller project and it worked pretty good. Thought that I'd invented a new process until a conversation at one of the forums proved me wrong. Someone else brought the idea up on the forum. Although not a new method, this is one you don't generally see on the woodworking shows on TV or on the web. The results are very nice looking and the setup is fairly straight forward.
The photo above shows the general setup. You determine the top dead center of you blade then lower the blade below the table surface. You then attach a temporary fence at an angle crossing the top dead center point of your blade. You then turn the saw on and slowly raise the blade, cutting into the temporary fence. You then lower the blade back down to where only about 1/16th to 3/32nds inches protrudes above the table. By feeding the work into the blade slowly along the fence, you begin cutting your raised panel.
The arrow "B" in the above photo indicates your feed direction and you make your first cuts on the end grain so any chipout will be removed when you cut with the grain. Some woods, walnut for example, have a tendency to leave a "hairy" edge on the end grain, but I found that by making a second pass at the same depth in the opposite direction cleans that up real nice. The second pass in the opposite direction on the end grain also cleans up a sometimes rough surface on other woods. You can change the amount of curve by adjusting angle "A". Closing it up gives you a tighter curve, opening gives a longer curve. You will need to make several passes, each one no more that 3/32nds inch, and the last one less than 1/16th inch to give a fairly smooth surface in the cut. A good sharp blade is a neccesity, along with a nice slow even feed rate.
These panels are ready for the last pass on the saw.
You will also want to have all of the panels for the project ready to go in one setup since duplicating the exact curve and depth is difficult without making a bunch of marks and measurements. I like to just set it up rum some scrap through, make any adjustments by eye, then cut away.
Here are the rest of the pieces I cut at the same time as those in the photo above. The two long pieces are drawer fronts and the others in this photo are the panels for the front of the blanket chest. The larger ones are the side panels. Setup takes just a short time, and each piece was run though at each blade height before the blade was raised to the next setting. I like the graceful curve a lot more than the straight line cut using the vertical method, and I didn't even have to buy another router bit.
A couple of days ago I came across a link at one of the forums where a fella had gone to a significant amount of work to put together some drawings showing different effects different angles of the fence and different blade tilts when making cove cuts. This opened up a whole new area for cove cuts and for doing raised panels in the manner I described above. He kindly gave me permission to link to his site and says he will be keeping the page up. Anyway, here's a link to his page of drawings:
http://home.usmo.com/~woodworking/Cove.htm
Though I knew that changing the fence angle to the blade would change the look of the cove, or in this case, the half cove, I never even though about the effects obtained by tilting the blade. So hop on over there and take a look.