Accurately placing holes?

[Luke Dupont]

I guess this is a very elementary question, but it's not one that I've found any good advice on;

How does one drill very accurately placed holes? I find that no matter how I attempt to start or mark a hole (awl, drill bit, gimlet, auger), the grain tends to move my tool slightly. In many cases, this doesn't matter at all. But in some cases, where millimeters matter, I really struggle with this. And, of course, once this happens, there's no way to really correct it.

I almost want to just sharpen a piece of wire, heat it up, and burn a pilot hole :D

But, seriously -- are there any techniques to accomplishing more accurate hole placement that I'm just not aware of?

[Jim Belair]

Brad point bits are a big help.

[Matt Kjolsrud]

Once your bit is positioned, take a couple of turns backwards/reverse. Then drill normally.

[Walter Barbier]

Read somewhere about using a nail set. I've tried it and it does work for me.

[Robin Frierson]

I use a very fine nailset or a sharpened thin finish nail which I give one tap with a hammer....then put the brad point in the hole.

[Doug Hepler]

Luke,

My solution is a bird cage awl and a brad point bit. But despite the name of this forum, I use a drill press. I have an auxiliary drill press table and can clamp the work piece in place when necessary.

I use an electric hand drill and a "portable drill guide" for dog holes and such that won't go to the drill press. I have never learned to drill a perfectly square hole with an eggbeater drill or brace and I feel no shame about it.

Doug

[Bill Houghton]

If you're using regular twist bits for your holes, start with a small hole - 1/8" or so, even smaller sometimes. And use an eggbeater drill or a push drill. Then step up in size.

For accurate placement, always mark the hole with an awl or similar.

[Eric Schmid]

What diameter bit are you using and how long? Small diameter bits, especially low quality bits, can flex and wander. Larger diameter benefit from a pilot hole. A center or nail punch will help establish the path. An awl will do as well.

I suspect it's the bit you are using. Good quality bits make a world of difference.

You can correct hole placement, but this usually requires doweling the misaligned hole and starting again.

[Alan Schwabacher]

One way to control that holes bored by hand are square to the surface is to control the angle you can't see by another means. If you clamp the work vertically in the vise, holding the work square to the surface in one axis means placing the handle of the brace at a particular height. Holding it to your hip at that height controls this angle, and you can easily see that the bit is square side to side.

Hole position is best marked with an awl, for the same reason lines are best marked with a knife: your tool fits in the mark, and you can feel that it's in place.

The trick mentioned works well of starting with a carefully located smaller hole, following by a larger one guided by the first. If you are using twist bits, the cleanest, roundest and most consistent sized holes will result from drilling sequentially with three sizes of bit: first a small pilot, then one smaller than the desired size by 1/64", and finally the precise desired size. It may not be worth the bother in wood, but it does improve precision.

[Luke Dupont]

Thanks guys - various things to think about here.

I think what I might do is fashion a very thinly tapering square awl (brad? birdcage? not sure the correct terminology here.) The awl I have now has somewhat of an obtuse point and is round, and I think that's allowing it to wander with the grain way more than I'd like.

This is mostly only a problem when accurately mounting hardware. For example, I was making a home-made wooden spokeshave, carved fitted recesses for the blade, and mounted it with screws. It worked in the end, but because the screws I used were the same diameter as the holes in the blade, there was no play, and I couldn't get the holes themselves accurately drilled, so things didn't quite line up correctly and required some "fudging."

I haven't made any boxes with flushed hardware, but I imagine I'll encounter similar problems with screw holes when I do.

PS. Just to clarify, my problem is just hole positioning, and not drilling straight or anything like that. I usually use an egg-beater drill or brace, and I find I can drill quite straight with either by using a small square as a visual reference for the angle that I can't see.

[Jim Koepke]

This is mostly only a problem when accurately mounting hardware.

This is where a gimlet can help. I will hold the hardware in place and use a gimlet until it hits the sides of the screw holes in the hinge or other item being mounted. The hole is centered and the drilling for the shaft and threads after this are right on.

jtk

[Robert Hazelwood]

A set of transfer punches can be pretty helpful for hardware installation. The punch will fit the existing hole and should leave a dead-centered mark in your work piece. The hardware has to have a little bit of thickness for the punch to work, however.

I like brad point or forstner bits for drilling wood generally, but especially for hitting a mark like this.

As for using an awl, sharpness helps, so grinding down the tip some sounds like a good idea. The other thing that helps is to make a light mark first, and see if its wanting to pull the mark off the line. If it is, then lean the awl back towards where you need the mark and increase the pressure. You can manipulate it a little bit.

[Bruce Haugen]

Wrong place for this answer, but if the piece fits on my DP, I'd use that with a centering bit.