Drilling Question for floating tenon.

[Raymond Fries]

I am making a Del Cover rocking chair that can be seen here:

http://www.delcoverwoodworking.com/contemporary_slat_back_rocker2.jpg

The chair will be made from hard maple and I am plannning on using floating tenons to assemble the four side pieces. To bore the hole in the end grain of the long piece that meets the rocker, I would like your feedback on the following idea:

I have an incra router table with the nice fence. I plan to clamp the piece to board wiich will be bolted to the router table fence in the T-Slots and raise the router to drill the hole. The mortise is 1 3/8" L 5/8" W x 2" D. I am planning on using a 2" spiral upcut bit. Using stop blocks and the fence, I can easily locate the position of the mortise. Since I only have a 10" bench top drill press, this is my alternative.

Does anyone see a flaw in this logic? I hate to be unsafe or ruin some nice wood. I have never drilled end grain with a 1/2" router bit.

[Jamie Buxton]

I'd do that job with a plunge router, but if what you have is a table-mounted one, that'll have to do. One thing you might check... I have a fixed-base router (a DeWalt). To change the depth of cut, I loosen a clamp and rotate the body in the base. The body is connected to the base with big screw threads, so that rotation changes the depth of cut. However, when the clamp is not clamped, the body is kinda floating loosely in the base. If I were driving the bit into wood in that state, I wouldn't be getting nice walls to the hole. The bit would be rattling around in the hole, because the body is rattling around in the body.


Maybe what you could do is to drill a pilot hole where the mortise will go. The pilot hole is a larger diameter than the router bit. You change the router's depth of cut with the router bit in the pilot hole. You can even change the depth of cut with the router off. A side benefit is that you don't even need to have a plunging router bit, because you'd never be cutting with the tip of the bit.

[Stephen Edwards]

I like your suggested technique IF your RT set up is such that you can accurately and safely raise the spinning bit up and into the work piece. Does your router table have a lift that would allow you to "crank" the router up during this operation?

[glenn bradley]

As Stephen points out doing this with a lift in a 'raise the bit to depth, lower the bit clear of the material, move material, clamp, raise the bit to depth' sort of a method sounds fine. In lieu of a plunge router which would be faster, this method sounds safe enough to me.

Its only a few cuts so I would go ahead unless you are looking for an excuse for a new plunge router ;-) What could be unsafe is having the bit buried in the wood and then unlocking your motor carriage if you have your motor in a standard cam-lock style fixed base and not in a router lift.

[Raymond Fries]

... a plunge router and a nice lift for my table. I have a DW625 router mounted in the Woodpecker's lift that you can just crank up. When the router is mounted in the table, I just keep it locked where it is plunged all the way down.

I thought about the plunge approach but was not sure if I could hold it as steady as having everything secured on the table.

Thanks for the feedback guys!