I often use a proto board as a template for drilling equally spaced holes.
Conveniently, the proto board has holes drilled at .1-inch spacing.
Use a bulldog clip to clamp the proto board to your work.
On the back of the proto board, mark the location where each required hole is to be drilled.
Drill a 1 or 2 mm pilot hole at each location.
Remove the drilling template (proto board).
Enlarge the pilot holes to their final size.
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