Drill press mortiser attachment setup

[Ed Beers]

I couple years ago I aquired a Jet drill press mortise adapter with along with a box of "stuff". From what I could tell it was never used.

This past weekend I finally got around to fabricating an adapter sleeve so can mount it on my bench top drill press. This seems to have been successful and I was able to cut some square holes in a 2x4.

However, the attachment came with no advise on use. Basically nothing but a mostly correct exploded diagram. So what do I need to know to use it effectively?

What speed should I run the bits at?

Do I need to lubricate the bit or chisel?

Anything else I can avoid learning the hard way?

Ed

[Gary Keedwell]

Ed, I had one years ago and threw it away. It was too aggravating. You said you tried it out with a 2X4? Well, I'm sure a few guys here might be able to help you. I bought a dedicated mortiser quite a few years ago and really like it. IMHO it is the only way to go.

Gary K.

[Jim DeLaney]

Ed,
Most of the dedicated mortisers - the small ones, at least - run at about 1750 rpm, and they work pretty well at that speed. So, run your drill at or just below that speed and you'll be okay.

As for the lubrication of the chisel and bit, there are many opinions on hwo and or whether to lubricate. Personally, I give the spinning bit a little spritz of Pam (the kitchen oil spray) if it starts to make noise. Otherwise, I don't lubricate.

Setting up the chisel and bit can be a bit frustrating, but here's the way I do it: I put the chisel in the mortiser, with a nickel under the flange at the top - that way, the chisel isn't fully seated in the mortiser. Then, I insert the drill bit and push it up snugly into the chisel till it 'bottoms out.' Lastly, I remove the nickel and seat the chisel fully into the mortiser. This gives the proper clearance between chisel and bit to prevent burning. It also minimizes the need for lubrication.

BTW, the chisel probably needs sharpening before use. I have a cone-shaped stone that I use to hone the inside, and I use progressive grits of sandpaper on glass to de-burr and polish the outside. I go up to about 1000 grit on the outside, but it's probably a bit of overkill. 400 or 600 would probably be plenty.

Hope this helps.