Looking for a tip to center my forster bit in my mortise

[Dick Snyder]

I have to drill out some mortises that are NOT centered in table leg I am working on. That means I can't press the bit down to make a hole and flip the piece to see if the point goes into the hole I just made. I have been experimenting on some scrap but I am always a little off. Why do I care? Before I start I cut a line with a utility knife on the sides of the mortise to "catch" my chisel blade but if I am a little off, I lose one of the lines. Am I just being too picky or is there some tip one of you can give me to get it dead center? BTW, the mortise is 1/4" wide.

TIA.

Dick Snyder

[dpb]

... Use a fence that can be adjusted.

When get close, if don't want to make a precise fence, use shims to "sneak up" on it.

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[Dick Snyder]

I have a fence but even when I place the piece against the fence, drop the tip of the drill bit down to just tap the wood and then snug the fence up to the wood, I am still not getting the cut perfect. Maybe I should make fewer holes with my drill press thereby leaving a bit of my scribe line to catch the chisel blade.

[sweet sawdust]

Try using your scribe knife to cut a line in the center of the mortise. use the cut to help guide the fostner bit point in to the exact place you wish to drill.

[MikeWhy]

That sounds complicated. s

[dpb]

I'm saying set the fence and test. If it's proud, adjust it back a squinch. If it's now not perfect, it should be a little too far back. If so, use a shim rather than fiddle w/ it unless have one of the adjustable jobbies w/ the threaded positioner or have made something similar yourself.

There is, of course, the alternative of locking the quill down and measuring from the near side of the bit face to the fence w/ dial calipers, but that would seem over kill...

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[Dick Snyder]

OK. I will try fiddling with the fence to see if I can nail this thing. Thx.

[Jeff Gorman]

"sweet sawdust" wrote

When this has been done, put a centre punch in the drill chuck and align the job until the punch's point registers in the line.

Jeff

[Upscale]

Would a centre punch help with your alignment?

[Dick Snyder]

That sounds like a *very* good idea! Thanks to you and to upscale for the idea for the center punch

[Han]

"Upscale" wrote in news:952f4$495c8155$cef88bc5 $ [e-mail]:

Could it be a problem with the drill not going in exactly perpendicular to the wood?

[Dick Snyder]

I don't think so. My drill press is perpendicular to the table. I think my problem is simple one of alignment but I have gotten some good tips about how to do that now.

[Lew Hodgett]

Classic application for a plunge router and a simple jig.

Lew

[Dick Snyder]

I made a jig for my router but I am doing 1/4" wide mortises in a piece of wood that is 7/8" wide. I like the idea of seeing what I am actually doing with the drill press.

[Lew Hodgett]

Guess I'm not following.

Router bit is visible as it penetrates wood.

Jig lets you maintain registration form piece to piece such as table legs, which will be more difficult trying to do on a drill press.

Lew

[Dick Snyder]

What I meant was that I can see the forstner bit as it enters the narrow piece of wood. I have a good fence that I made for my drill press so I can get repeatable results. This might just be psychological but it is hard to see through the router base to see what is really happening. I supposed if I used a router a lot for mortises there would be no issue. Clearly there is much less chiseling required with a router and jig and maybe none if I round the ends of the tenons to match the radius of the router bit.

Dick

[whit3rd]

Unless this is a rather small item, consider making your mortises wider than your Forstner bit. As far as straight drilling goes, do you have a drill press that swivels to drill next to a good wood vise? It's hard to beat the accuracy of a well-mounted vise, and a little shimming will keep the wood in the right place for through drilling. If there are lots of pieces to be pierced, replace the stationary wood jaw with a customized one of the correct thickness.

For deep holes, an auger bit is nearly as accurate as a Forstner, and the chips clear easier. If you really want

1/4" mortise, consider an undersized (7/32"? ) brad point drill bit.

[Pat Barber]

Look at this device for that problem.

would also look into making my mortise with a router and a jig.

Dick Snyder wrote:

[Lew Hodgett]

I was going to say, "Sounds like a personal problem"' ,but you beat me to it.

BTW, any router I've used provides a direct line of sight to see the bit as it enters the wood.

Once you start using a router for mortises, you will want to kick yourself for waiting so long.

Lew

[Dick Snyder]

Lew, would you mind telling me what jig you are using? I made one based on a posting some time ago in this group. Did you make your own, and if so, is there a link to it so I can see what you are using?

Dick