Vertical holes - exploration
My first step was to try a crude experiment just holding a piece of 20mm dense chipboard and drilling holes from both sides.
Holes 1, 4, b and c where drilled from one side and the others by turning the wood over. To start with the drill stand has a sideways movement of around 0.85mm of travel at the drill bit - so I need to come up with a way of stopping that !
I would have been a good idea to use a sharp drill and I also found if difficult to measure the distance between the holes with my Digital Micrometer as the claws would not fit all the way through the holes. Either bigger holes are needed or I need to insert the drill bit (2 off) to be able to measure more consistently, as I got up to 0.04mm variations between measurements.
The minimum distances were (top to reverse side)
1&4 - 31.45 and 31.72 - giving +0.27 difference
b&c - 19.05 and 19.16 - giving +0.11 difference
2&3 - 8.50 and 8.58 - giving +0.08 difference
a&d - 42.62 and 42.79 - giving +0.17 differencequite a variation. So I need to be more precise.
The experiment needs to be carefully set up and conducted as follows...
The diagram opposite represents these. Starting at "A". Each line shows the exaggerated differences one would get if the drill was non-vertical in both dimensions. Of course only two of these orientations are required to be able to deduce the angles, but I shall drill a cluster of 4 holes on each of the 4 orientations, which will help determine the consistency of the drill.
The three diagrams below show the different results if the drill is not out in both dimensions.
How can I be sure that the drill is parallel to the pillar? I'm not sure how this can be determined!
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