Drill template for fitting things on board
A printed template with a lip that registers against the edge, holding the bolt pattern in place while you drill the console.
The problem
Four holes in a console have to match the pattern on a bracket you cannot hold in place at the same time. Mark it out with a pen and a rule and the last hole is a millimetre out, which leaves the whole bracket on the skew.
The fix
The template is printed with the bolt pattern and a lip that sits against the edge of the console, so there is only one place it can go. The holes print 0.2 mm under nominal and are opened out afterwards, since printed holes come out tight anyway. It is a template for pilot holes. Plastic will not guide a large bit well enough, and the last millimetres are done by hand.
PETG lasts a few dozen holes before they start going oval, and then the template is printed again. It is a consumable, not a tool. The order of work is the same as before a dive: check what is behind the panel first — cables, tank or foam — and take the pilot hole first. A template does not remove the need to look.
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