With the small section of 4mm thick copper cut loose from the old printing plate a 4mm grid was marked over its entire surface. A ruler and an indelible marker were used to layout the pattern of points which were then marked with an automatic center punch. Considering all the work that would be going on with this little bit of copper, any markings that could come off, would have. The punched points also served as starting points for drilling.

The coping saw cut the copper section away, the ruler and marker marked the points where pins would eventually go, and the hole punch ensured those markings stayed put as we set to work.

The 40mm X 50mm piece of copper with all 110 pin positions marked on it was then clamped to the work bench. Drilling the holes in the copper caused the block to reach a really high temperature. After a few minutes of drilling it was literally too hot to handle, this despite the fact that we were only drilling less then 3mm into it!

For this heatsink we used a Fordom drill to bore the holes. It's a lightweight drill which is a similar to, but a big step up from the Dremel. The big plus with the Fordom is better control over the drill bit and the speed at which the bit rotates (via a foot peddle).

Masking tape marked a point 3mm up from the tip of a 1/8" HSS bit. Since the copper plate was only about 4mm thick, the last thing we wanted was to accidentally drill through to the other side. With the tape on the bit it served as a visual point from which to stop drilling.

A small canister of felt, saturated with oil, helped to lubricate the tip of the drill bit at regular intervals in the drilling process. Proper lubrication not only prolongs the bits' life span but yields cleaner holes. The markings with center punch proved invaluable to keeping the drill bit where it was supposed to be instead of having it stray off to one side.

Drill, oil and clamped down copper slug as we pause half-way through the procedure.