Curved cove cut

[Greg Jurrens]

I'm designing a piece of furniture that will have a table sawn cove that would follow a curve. Does anybody have any suggestions or experience in doing such a cut?
Greg Jurrens

[Joe Jensen]

If the curve is a fixed radius, then I think you could just create a pivot point and rotate the stock around the pivot point over the blade. You would need to have the pivot point offset so the blade path does not point towards the pivot point.

If the curve is not a fixes radius I think it would be VERY challenging, the kind of challenge I like...joe

[Michael Schwartz]

You are going to need a well designed jig to do this if it can be done.

I have cut coves on the Table-saw and it is a legitimate thing to do. I am not really sure about the possibilities of adding a radius to that. I hate saying thigns can't be done, and I am sure somebody has at the very least tried this before.

It sounds like this could be potentialy dangerous. Whatever you do make a jig that holds the work piece dead secure to prevent any possibility of any kind of kickback.

Hog out as much as you can before hand with a plunge router or whatever works.

A possibiliy might be to make a jig for a handheld circular saw.

I suppose there is some way to do this with a shaper as well.

Worst case scenario, Find someone with a CNC router.

[Craig Feuerzeig]

This was recently the subject of one of our woodworking guild meetings. Stephen Proctor was the featured speaker. Fascinating stuff, and this crowd doesn't easily impress.

You'll need to make a dedicated jig for each different radius... to slide the workpiece over the table saw blade...the angle of the feed and the tilt of the blade already figured out in advance, depending on your profile. Safety wise is not a huge problem as long as the jig is clamped in place securely, as most of the blade is hidden under the jig. Use an old blade and raise it into the workpiece no more than 1/8" at a time until you reach the desired depth.

He sure made it look easy.:rolleyes:

[Jamie Buxton]

There are also router bits which cut a cove. For instance http://www.eagleamerica.com/product.asp?pn=130-2815 In my experience, the router bit requires less sanding than the table-saw method. Despending on the size of your molding, you might find that edge-guiding a router is easier for you. Or course, with the router bit you only get the radius which the bit supplies, which is less flexible than the table saw.

[David DeCristoforo]

"...I suppose there is some way to do this with a shaper as well..."

That's what a shaper is for! Limited by the size of the cove and the capacity of the machine. If you need an 4" radius cove, that's a pretty big cutter.

Doing this on a TS should be OK as long as the forgoing advice is followed...solid jigs, proper feed direction, etc. plus multiple passes, very small cuts and as heavy (thick) a blade as you can find.

[Justin Bukoski]

Does anyone know of a good source for a shaper cutter that will cut a cove in the piece without making the back cuts for cove moulding? I can't seem to find one anywhere.

[Greg Funk]

Does anyone know of a good source for a shaper cutter that will cut a cove in the piece without making the back cuts for cove moulding? I can't seem to find one anywhere.
You could get a molding head that accepts custom ground knives like this. The initial head is a little pricey but after that the knives themselves are reasonable. It's a scary beast to run though...

Greg

[Bill Wyko]

Rockler has a fence for making cove cuts on the tablesaw. I built my crown molding by making my own diagonal fence to the blade and raising it 1/8 of an inch at a time to get the curve to the right depth.

[David DeCristoforo]

"...Does anyone know of a good source for a shaper cutter..."

If these guys don't have it, they will make it for you:
http://www.nordicsaw.com/

"...molding head that accepts custom ground knives like this. The initial head is a little pricey but after that the knives themselves are reasonable. It's a scary beast to run though..."

Ditto that. High speed steel cutters for these can be ground by and decent local saw shop. For small runs, I like HSS better than carbide because it can take a sharper edge yielding cleaner cuts. As to the scary part, a head like that with knives that size should not be run on a spindle smaller than 1.25" Bushing this setup down to run on a 3/4" spindle would really be asking for it.....

[Greg Funk]

Ditto that. High speed steel cutters for these can be ground by and decent local saw shop. For small runs, I like HSS better than carbide because it can take a sharper edge yielding cleaner cuts. As to the scary part, a head like that with knives that size should not be run on a spindle smaller than 1.25" Bushing this setup down to run on a 3/4" spindle would really be asking for it.....
I ran it on a 1" spindle. Regardless of what spindle you run it on it still sounds and feels like a jet engine.

Greg

[Joe Jensen]

You could get a molding head that accepts custom ground knives like this. The initial head is a little pricey but after that the knives themselves are reasonable. It's a scary beast to run though...

Greg

How would you run the stock with that? Vertically?

[Greg Funk]

How would you run the stock with that? Vertically?
Yes, with a power feeder.

Greg