need suggestions for improved drilling

[john bateman]

I have this drill press:
http://www.portercable.com/Products/ProductDetail.aspx?ProductID=24037 , not the best, I'm aware, but until now it has done OK.

I am currently trying to drill 3/8" dia holes through the center of 2" dia poplar dowels that are 3-1/2" long. I'm drilling lengthwise, (concentric) and though the brad point bit starts pretty close to dead center at the top end of the dowel, when it comes out the bottom it is off by about 1/16".

I made a jig to clamp the dowel stable. So far, I have checked the dowel, which I am crosscutting on my table saw, to be as perfect as I can tell to 90 degrees to the dowels sides.
I also put a 8" steel rod into the drill chuck, and checked it for perpendicularity to the drill press table. It only looks to be about .010" out of perpendicular...not the .06" error I am getting when drilling.

So am looking for ideas on how to improve things. I need to make 12 of these, and while they don't need to be machine shop perfect, I'd hoped to do better than I have so far...perhaps an error of 1/32" or less.

Thanks for any advice.

[Brian Holcombe]

Drill to center from both sides.

[John Lanciani]

Any chance you have a lathe? Much easier to drill this hole that way. Also, brad points are not the best for end grain, look for a parabolic flute bit like pen turners use.

[David Eisenhauer]

The tip of the drill is probably going to follow the end grain at some point along the way down. I'd try Brian's suggestion to drill halfway from each end if I had to have it dead on. Easy, easy pressure on the "down" handle to help prevent any stress to the drill which can create minute flex.

[Lee Schierer]

A couple of things to do and try. Make sure you clear the chips out of the drill often. Start your hole with the brad point bit and then switch to a regular twist drill bit.

[john bateman]

I was reluctant to drill from both ends, as eventually a 3/8" threaded rod has to pass through the hole. But I just tried it per the advice of Brian and David. The misalignment where the 2 holes met was pretty small. I was able to push the threaded rod through a couple times and it acted like a file, reaming away the small error. Thank for the help!

[Bob Hoffmann]

I would drill a small hole first from both sides -- say about the size of the point on the brad point drill. Then drill thru from one side with the final size -- this will make sure that you will not have a mark in the middle if you use the final size and drill from both sides.

[Sam Puhalovich]

+1 on drilling from both ends ... not with a bradpoint.
Get a center drill ... and use it drill 5/8 - 3/4" into each end.
Switch to a conventional drill bit ... it will follow center drilled hole.