squaring Delta 16" DP to mortise

[Keith Boeheim]

I recently bought a Delta 16" DP and it came with a mortesing set free. Yes I know a dedicated mortiser is better and that the chisel set is not the best but I'm going to give it a go.

What I notice is that when I move the DP table up or down it can also swivel making it out of square with the mortise. How do I square the table to the bit?

Thanks for any help

keith

[BobS]

It would be nice if you had a blank drill rod or a piece of 1/4" or 1/2" rod that you know is straight. Failing that, use the longest "good" drill bit you have and be sure to roll it on a flat surface (TS) to check that it is round and not bent. Chuck that up and use your Engineer square (or equivalent) and adjust the table height so you get the maximum amount of the square against the exposed part of the drill bit. Start with the square at the 270° mark (easier to see) and sight along the blade and drill bit. Adjust table so the square is parallel to the bit. Move the square to the

360° position and do the same. Move to the 90° position and repeat - it should be parallel.

Another old trick is to simply take an old coat hanger or other piece of heavy wire about 12" long and bend it into an L shape with the long vertical section (8" long) being chucked in the drill press. At the end of the short section of the L (make that about 4" long), bend down about a 1/2" length of the wire to act as a scratch nib. Bring the table up until it just touches the wire. Rotate the chuck by hand and adjust the table so it just touches the nib at any position. Don't bend the wire when it's being used - it will be the same length no matter the rotational position of the nib as long as you keep your hands off it and it's not deflected.

You may have to make some adjustments to the table adjustment mechanism if you can't get the table perpendicular to the chuck. Both these methods are rough alignments and for precision alignment, I would use a dial caliper and a known reference (uncut drill rod) that is within a couple of thousandths of being straight and round. That's a whole 'nuther procedure....

I'm sure there are many other innovative methods that will work but essentially - just about any method that aligns the table perpendicular to the centerline of the drill chuck will work - just a matter of how precise you want to be.

Bob S.

[Rumpy]

I don't think his question is squaring the table to the quill, I think he's asking how to get the fence square to the chisel. I have a designated mortising machine, and I just push the fence against the bit until they are square, tighten the bit and readjust the fence. You will need a fence attached to the table to keep your work in line as you make each cut. Since you cannot move the fence without changing the angle, I guess you will need to use an appropriate spacer to get the face of the chisel parallel to the fence. I have never used an attachment, so someone with more experience might have a better idea.