Safest way to route rabbets on curved profile?

[Thomas Colson]

Getting ready to make a bunch of zero clearance inserts for my Delta 36-725, which calls for curves. Cutting the insert to fit the hole isn't the challenge: it's rabbeting that edge profile so I can use the set screws. My options are a 1/2 shank rabbeting kit with the different size bearings that I can use in the table, or a 1/4 inch shank version I can use freehand in the palm router. In considering which way to go, I'd like to, in the future, be able to rabbet other things (e.g long pieces), so the 1/2 " in the table seems obvious. But freehanding those radius ends on the table scares the heck out of me, whereas I'm pretty comfortable doing it with the palm router. What's the best option here, where I don't route my fingers off? Another consideration is this won't be the only curved work I'll want to rabbet, either. https://www.youtube.com/watch?v=lDzyKPEO8ME makes it look TOO easy with the palm router. I'm skeptical!

[Marc Fenneuff]

Have you considered holding the piece with a couple push blocks?

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[Matt Day]

Here’s an LJ’s thread on it:
https://www.lumberjocks.com/projects/133305

And here’s a YouTube video on it.

https://youtu.be/lDzyKPEO8ME

[Steve Demuth]

It can be done quite safely on the table. Start by having a true zero-clearance fence for the exposed bit profile. Literally, the only part of the bit that should be exposed on your side of the fence is the height and depth that you are cutting to. That way you can always have the piece supported on three sides of the bit as you move it through the cut. On the radiuses in particular, you can support the cut side fully by controlling the way you rotate through the cut. (This will be true for any convex cut you want to make in the future. Concave curves are a different thing. Second, use a proper bit shield over the top of the bit. If you lose control of your piece (you won't, but safety is in the margins), that will keep your hands in the clear. Third, if the piece you are cutting is not large and lacks mass, make it bigger and more massive with some combination of jigs and technique. Good high-grip push blocks can help, but if that leaves you still feeling not quite in control, use a jig. I have one that allows me to hold small pieces (way smaller than your insert) for this purpose. Lastly, if you're still nervous, don't cut the whole depth in one pass - smaller engagement makes for better control.

All of that makes this sound harder than it really is. For something as big as a zero-clearance insert for a table saw, I'd bang the bit into my table, adjust the router zero-clearance, and route it using high-grip push blocks without a second thought.

[glenn bradley]

Yep, router table with a bearing guided bit. Easy-Peasy.

[Steve Rozmiarek]

Safest, also probably the most expensive and interesting.


https://cdn.shopify.com/s/files/1/0978/7942/products/78840a_1000x.jpg?v=1519100024

[Curt Harms]

Safest, also probably the most expensive and interesting.


https://cdn.shopify.com/s/files/1/0978/7942/products/78840a_1000x.jpg?v=1519100024

But how do you plug it in? :D

[Lee Schierer]

When routing curves you need to watch the grain closely. The diagram below shows the proper way to go around a curve. If you cut the curve all the way using normal cutting action you can get some serious blow out when the cutting edge hits directly on the end fibers of the grain.
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[Bill Dufour]

I forget the name but it is a simple steel rod sticking up out of the table. The work bears against it at all times as it rotates around the rod until it contacts the cutter.
Bil lD

[Andy D Jones]

But how do you plug it in? :D

It's cordless... You recharge it at the dinner table.

-- Andy - Arlington TX