Hi Everyone.
I'm working on a little project that will require threading together ten 1/4" x 1-1/2" x 12" New Zealand pine boards to form a flexible shelf. Since I'm using natural hemp string, I need to literally drill 1/16" holes all the way through the 1-1/2" boards. That gives me just about 3/32" of clearance on either side, so precision is really important.
I don't have a top-of-the-line drill press; it's a Wen 4214 with the Wen Drill Press Table attached. I have confirmed using the 135 degree bent rod sweep technique (actually, I found it best to use a Staedtler compass with a piece of paper on the DP table). In terms of calibration, I think my biggest problem is the angular "play" which appears to be increased significantly when using a 1/16" bit. To be specific, if I chuck a 1/2" steel rod, I get right around 0.004" of play, but with the 1/16" bit, it increases by 3x to 0.012.
To guarantee right-angle, I created a simple jig using two machined steel right-angles held together by M5 machine screws, and mounted to a flat piece of 3/4" MDF to reduce tearout. I then use an Incra Rules to poke tiny holes dead center and 1/2" in on both sides of the board. When drilling, I go half-way through on one side and half-way on the other, then test my success using a straightened-out jumbo paper clip.
Even with all my best care for accuracy, I still only have a 50/50 chance of having the two holes meet. For the ones that don't create a through hole, if I pick a side and drill all the way through, the bit will come out off center or worse on the corner edge.
At this point, I'm really considering a higher end DP, but since I only do woodworking as a hobby, it just doesn't make sense for me to spend big $$$ to solve this before I know what's really wrong.
Any insights from the SC community would be greatly appreciated.
Tony Gardner
Ruckersville, VA