I posted the answer on the Yahoo group because I saw it there first. Sorry about that Scott. I am repeating it here because I think it is worth having in the archives of this group. I also had a chance to edit in posting it here.
After all of the vise and vertical alignments of the drill press, table and fixtures have been taken care of, we are still not guaranteed a straight hole in a peece of wood. Many dilling problems can start at the initial entry of the drill bit into the wood. We are drilling onto end grain, and because of the varying density of the wood, the drill bit will want to take the path of least resistance, which is not always the one that we want it to start on. If the bit moves off of center at the start of the hole, chances are that it will continue to follow that path that is at an angle to the centerline of the drill press or lathe. The 7mm drill is flexible enough that it can be off as much as 1/8" or 3/16" in the length of a 2" long piece of wood.
There are three ways to prevent this from happening, and none of them
have anything to with how the wood is held in vertical alighment with
the drill bit........
Cut the end of the pen blank square to its length, and as smooth as possible. When this surface is square to the drill bit as it enters the wood, both sides of the bit will start cutting at the same time.
The smoother surface prevents surface ridges from influencing the drill bit at entry.
Once the hole has started, and IF the drill bit has pulled off-center enough that you can see it (Watch the tip of the drill as it enters the wood) - move the piece of wood around until everything is lined back up again before drilling on through the wood. Otherwise, the drill bit will continue to follow the line that is at an angle to the one you want. It may still want to wander as it goes down through the wood, but you will have at least started it straight. Being able to move the wood around is an advantage of the drill press. Not being able to re-orient the wood is a disadvantage of drilling in the lathe or having a fixed fixture for holding the wood in the drill press.
Use a drill bit that is the less suseptable to following the path of
least resistance as it goes into and down through the wood. I know
not everyone will agree with my opinion, but...
The standard twist drill is the most influenced by the wood grain, the most likely to get started off-center, and the most likely to follow the wood grain as it goes through end-grain wood. An advantage of these drills is that they are easily sharpened, but unless you use some type of jig that ensures that both sides are equal, the unequal
cutting edges from a "free hand" sharpening can make it worse than a new drill.
The "Bullet Point" drill is the least likely to be influenced by the wood grain at entry, and the least likely to be influenced by the grain as it goes through the wood. That little pilot hole in front of the main drill was a wonderful invention. I haven't figured how to sharpen one of them yet.
The brad point drill can be somewhere in between, but depending on the
wood can be worse than the standard twist drill at entry and as it goes down into the wood. If the wood has a strong grain, the sharp point on the center spur will skid to the side when you try entering the wood along a hard grain boundary. If a sharp nail driven into the end-grain will move to the side to find softer wood, the sharp point of the drill will do the same. Once started into the hole, the spurs at the OD of the bit are supposed to keep the point from following the grain. However, in end-grain wood that has a strong grain or in laminated wood, the sharp knife-like and unequal angles of the cutters will make them also want to follow the grain, and the result can be the worst of all drill bits.
Now, you will have to hold the wood in vertical alignment with the
drill bit, and that is a problem with the vise or whatever else you
are using and the table being square to the quill.
None of this will guarantee a perfect hole, but it will eliminate a
lot of the drilling problems.
Russ Fairfield