Raised panel on table saw -- acceptable method?

[Nate Perkins]

Hi all,

I'm working on one of my first large projects using raised panels. I am using a modification of a cove cut on my tablesaw to make the raised panels. I've tested this method on one panel, and it seems to give fair results and it appears to be safe ... but I'd appreciate experienced opinions.

Here's the deal: I've got 3/4" thick cherry panels, that I'm raising to fit into a mortise/tenon frame (dado width about 3/8"). I clamped a flat sacrificial hardwood fence at about a 45degree angle to my blade, and running right over the top of the blade. The leading edge of the fence is forward of the high point on the blade. Then I raise the blade in small increments and pass my board across the sacrificial fence. Raising up the blade in steps, I get a pretty good concave cove, albeit with a little loose fiber on the end grain that scrapes off pretty well. I've only tried this on one panel so far, but it seemed to go okay.

My question is, does anyone else use a similar method? And are there any severe safety gotchas that I may be missing? (I did do a google search, but just got a bunch of hits related to vertical panel jigs on the tablesaw).

Thanks! Nate Perkins Northern Colo

p.s. I am doing it this way because I don't own a good router/panel raising bit.

[BurlaT3]

You go Nate! Yes it is acceptable. It can be dangerous but what isn't. I have had several occasions for very large cove where I used the same method. It is SOP, go slow and get ready to sand alot. If you really get into this kind of cutting call Ballew Saw and Tool in Springfield, MO and you can get a trim makers set that includes a 10" (I think) TS Blade about 1/2" wide with rounded teeth that really would do a sweet job. I've been drooling over that for a while now. I think it costs about $250, which would pay to have at custom milling prices or even big molding prices, eventually. (justify,justify,justify)

Another note - be careful not to cross feed to fast with to much depth of cut or you could flex the blade and a tooth caught on an insert is not a good thing. I usually put on my dado insert.

Good luck with your project.

[Rob]

Let us know if you complete the project with all of your fingers still attached.

It might be safe. I've never done it. But it sure makes me nervous....

Good luck!

Rob

[Bob Bowles]

[Igor]

About a year ago, googling the NG, I found strong recommendations for a classic book, Complete Book of Power Tools by De Christoforo. I got one used via Amazon's site. Hardbound, printed in '72. In the book, the technique you describe is shown -- though for what appears to be moulding, not a panel. So, it shows the cove being cut so that there is wood on both sides of the blade and the person is working from the clamped-fence side pulling the stock to the fence. Also, in the photos that show blades being used on the TS, the examples show maybe 15 and 30 degree angles, at most; there is a photo showing what seems to be a 45 degree when using a molding head cutter. Whether any of these details of the examples are critical/safer -- such as the stock having two "legs" to ride on when cutting -- don't know. Anyway, FWIW, one recognized expert thinks this is OK.

I just reread the text and here is a suggestion about the angle of the fence. The point is to determine the correct fence angle. You build a frame w/ two long pieces on the flat and then two cross pieces near the ends. Let's say 20"x8" inside dimensions. Screw the top pieces to the bottom ones so that you form a rectangle. Just be sure that the distance between the long sides is at least as wide as your cove -- assuming a 180 degree cove versus a 90 degree in the panel. Then, you can flex the frame from a reg rectangle into a parallelagram so that the distance between the long sides of the frame is the desired width of the "full" cove. Then raise the blade to the final cove height you want. Finally, turn the entire frame at an angle until the inisde edges of the frame's long sides touch the front and back edges of the blade. Voila. You have your fence angle. HTH.

[Nate Perkins]

Great, thanks to you and the other responders. I had been using a homemade zero clearance insert -- I'll pull that out straight away and put in my dado insert. It gives reasonably smooth cuts on all but end grain. I do have a good saw blade (Forrest), but of course it is nothing like the Ballew blade.

I based the idea off of articles where they cut full coves on the table saw. I thought that was a bit scary because the board rides over the full blade, and it seems like it would be very easy to get it to kick back.

However, in this case only the leading quarter third of the blade is exposed, and it is only about 0.4" above the table at most.

It does make me wish for a better router and a panel cutting bit. Hmm ...

[Nate Perkins]

Ok, panels are made and fingers are all still attached :-) Seriously, no mishaps at all and the operation seemed to be safe with little load on the blade, as long as the depth of cut was kept shallow on every pass.

A curved card scraper (is it called a gooseneck?) took care of the rough surface that would have otherwise been a real bear to sand out.

Cheers, Nate