Woodworker's Journal Nov.& Dec. 2003

[Paul O.]

Anyone have these issues laying about. In the Oct. issue there was a couple formula's for calculating cove cuts on the table saw, pg. 60. The author was using Excel spreadsheet. I am trying to use MS Works and was successful with the second formula for fence angle, however the 1st formula for slot length don't compute. Was wondering if there was a correction in either Nov. or Dec. issue. No luck tonite getting to the Journal's web site.The formula in the mag is: =2*SQRT(25-SUMSQ(5-A2)) if that helps. Thanks.

[RKG]

Fine woodworking has an on line version here.

[Paul O.]

Thanks Rick. From a couple other sites I have gotten I don't think what I wanted to do is possible. I wanted a 4 1/2" wide X 1/4" deep cove in a 5" wide board. May have to figure out something else that I can do for design with router bits I have.

[loutent]

I needed some (approx) 4 inch wide oak cove oak a few weeks ago - making a mantle shelf. I could not find a local source, so I decided to try to make my own on the TS using some 1 x 6 oak from HD. I remember seeing the article that you mentioned, but I'm more of a show-me type of person when it comes to woodworking. I had never tried this before.

I used some scraps of plywood and ran a few test pieces through at different angles until I came up with what I wanted.

It worked out fine except for a couple of caveats. The wider the cove, the more passes (and effort) needed to maintain a consistent profile. Also, I was not expecting to have to sand the molding as much as I did to remove the saw kerfs (I used a 60 tooth blade). Made the passes very slowly too.

I also made some 1.5 inch cove which was a snap compared to the bigger stuff.

In the future, I have no reservations about doing this again. You save a lot of $ (especially with the bigger sizes) and get the exact width that you want.

Lou

[WoodchuckCanuck]

Hi Paul O,

I've seen a jig online that can help calculate cove width etc. Of course, I've hunted but can't find it now. So I drew up a crude drawing on MSPaint as a gif image here

've never used the jig but here's my theory. Anybody...feel free to add or correct if needed.

What you do is take 4 sticks (2 blue and 2 green) and attach them so they fully pivot. A recessed nut and bolt should do the trick. Stick dimension can be 1/2x1/2 or 3/4x3/4, doesn't matter. I would use

1/2x1/2 for mine. I'll explain why later. You'll probably not make a single cove molding any wider than maybe 6 inches so the max width between the two blue sticks will be about 6 inches. So the green sticks will be about 7 inches, giving extra room for attaching the green to the blue. You get the idea.

For your example of a 1/4 inch deep by 4-1/2 inch wide cove, first set the balde height to 1/4 inch. Then open up the jig and position it on the tablesaw as shown in the picture. Bring the blue sticks to the cutting tips of the blade. Next rotate the jig clockwise until the distance between the two blue sticks is 4-1/2 inches. This is the angle you will use. Then proceed with the normal start of making coves on the tablesaw.

I would use blue sticks that are 1/2 in width. Once I have my angle figured out, I'd clamp two straightedges on either side of the jig, then remove the jig. The distance between the two straighedges is 5-1/2 inches. I'll now pass a 5-1/2 inch board to make my cove molding. If

5-1/2 is too wide for the install, no big deal. I can always trim it up to the specs I need after I'm done.

Oh yes, cut more than you need...just in case. :-)

Hope that helps. Woodwork Safely, Jim Barry

[WoodchuckCanuck]

Hi Paul O,

I've seen a jig online that can help calculate cove width etc. Of course, I've hunted but can't find it now. So I drew up a crude drawing on MSPaint as a gif image here

've never used the jig but here's my theory. Anybody...feel free to add or correct if needed.

What you do is take 4 sticks (2 blue and 2 green) and attach them so they fully pivot. A recessed nut and bolt should do the trick. Stick dimension can be 1/2x1/2 or 3/4x3/4, doesn't matter. I would use

1/2x1/2 for mine. I'll explain why later. You'll probably not make a single cove molding any wider than maybe 6 inches so the max width between the two blue sticks will be about 6 inches. So the green sticks will be about 7 inches, giving extra room for attaching the green to the blue. You get the idea.

For your example of a 1/4 inch deep by 4-1/2 inch wide cove, first set the balde height to 1/4 inch. Then open up the jig and position it on the tablesaw as shown in the picture. Bring the blue sticks to the cutting tips of the blade. Next rotate the jig clockwise until the distance between the two blue sticks is 4-1/2 inches. This is the angle you will use. Then proceed with the normal start of making coves on the tablesaw.

I would use blue sticks that are 1/2 in width. Once I have my angle figured out, I'd clamp two straightedges on either side of the jig, then remove the jig. The distance between the two straighedges is 5-1/2 inches. I'll now pass a 5-1/2 inch board to make my cove molding. If

5-1/2 is too wide for the install, no big deal. I can always trim it up to the specs I need after I'm done.

Oh yes, cut more than you need...just in case. :-)

Hope that helps. Woodwork Safely, Jim Barry