how do I cut this out? (look at diagram)

[david gelwicks]

I was wondering on how to go about this inward crescent cut. I checked out a mill shop which will charge me about $7 a foot. Is there a cheaper way to do this on my own? Thanks for your help.

http://epmedia.ecollege.com/media/fl...tic/test/1.gif

[Ziggy Diaz]

David, Hi

Here's a short answer to your question, if you have a table saw, yes you can make the cut, and a lot cheaper, for about $20.00 you can biuld this fixture that will enable you (or whom ever lends you his TS)to produce ilimited amounts of the moulding:

http://www.taunton.com/fw/features/t...ovemolding.htm

Let us know how it worked.

Ziggy

[smjsimpson]

The fixture referred to is a nice idea, but you can still do the job by just clamping a fence at the angle to the blade that you need to make the cut. Determine the angle by sighting over the blade at an angle, clamp the fence in place, and push your piece through.

However, you can determine the angle also by taking the width of the cove you want, put two boards in parallel, spaced by this same width (and clamp them at this parallel position). Then, raise your blade to the height that gives you the right depth. Put the parallel boards over the blade and twist until the front and back of the blade touch each side of the parallel pieces. That's the angle you want, so put the fence at that angle, spaced away from the blade but the amount of the edge next to your cove.

Then, lower the blade and take multiple passes with your piece, raising the blade each pass until you get the depth you want. Speed of your feed will determine the "smoothness" and the amount of sanding you need to do.

[rrich]

I've seen this cut done somewhere on the tube. As I recall the curve of the concave cove is controled by the angle of attack at the saw blade. Also, the big trick is to go easy on the cut depth. Some say 1/8" but if you do the last couple of cuts at 1/16 or 1/32 there will be less sanding. You should measure and record the layout of your fence angle so that it can be repeated. Measure from the side of the table and along the edge to the cut side of the fence. Do this on both the front and back of the table. The next time that you have to cut a cove, the set up will be in seconds w/o the need for a dozen trial cuts.

Rich

[karl in pa]

This can be done very easily with a radial arm saw. Set the head to the rip position and angle the head until you get the proper depth of cut, etc.

[Ark]

I made the cut for the first time just before x-mas the way smjsimpson describes and the technique worked well for me and was safe. I wonder if the blade matters much. I used a 40 tooth blade with alternate tooth bevel. The cut turned out well but I wound up with more sanding work than I would have liked. I only have the one blade so it was still acceptable. Is there a better blade for this kind of work?

[GaryMc]

...I would consider use of a router. I believe they make cove molding bits (e.g., MLCS) up to a width of about 3 inches. If your width is greater than that, consider making two identical halves (either with the cove bit or a large panel-raiser) and gluing them together.

Also, somewhere in the WW mags for the past year I remember seeing a router cradle-like jig to cut out dish shapes.

[Lou_williams]

I have admitted that I don't use a router as much as most other woodworkers, Comes from having a bad experience with routers and bits early in my woodworking. Thanks Sears.

But using a router to cut that type of cove seems to be a lot more work than using a Table saw. I use routers for tasks that they are very good for. Edging dado's and the like. I have used them for both mortice and tenon cuts with good results, but swinging large bits to cut a molding is not something I would like to do with a router. Even with my shaper and panel raising bits it scares the **** out of me and I only do it when I have to.

Setting up an fence with a couple of clamps to the table saw and raising the blade a few times as you pass the wood across the blade is easy and much safer in my opinion

[Larry Rine]

How about an "old" hand plane? Of course this depends on how much sweat you want to put into this cut. You can find these former tools of choice at antique stores. Instead of producing dust, you produce nice shavings with hand planes.

If you really want to get "old school" you can make the plane yourself to fit the cut! Most of these planes were made out of boxwood.

The choice is up to you. There are at least 10 ways to solve any
problem.

Just a word of caution: if you opt for the 3" cove bit for your router, make sure you use a 3HP router with it.

[Greg]

The table saw idea is probably the easiest. But note: using a smaller diameter blade will result in a more circular channel (in cross-section). The larger the blade, the less "skew" is the feed, which leads to a more elliptical cut. I don't know how noticible a difference there is between an 8" and 10" blade, or even if you need the cut to be circular, but it might be important to you.

Greg