So I've seen drillings in chain rings plenty, both for weight and aesthetics. Seen it in lots of hubs too. When I took a look around though there was only one crank I found:
I just picked up a pair of similar Sugino Mighty Competition cranks below:
I'd like to replicate the drilling down the flute of the arms, and a few holes in the flutes of the spider too. I think small holes like that just in those fluted areas should be safe. I know later models of the Sugino Mighty cranks had those spiders bored completely out, so some holes should be nothing compared to that, and as far as this design goes, I found nothing about these cranks breaking or having weakness in the arms, so I'm having trouble imaging I'd be in any trouble there. I'm only 150lbs, and although I'm strong I'm no 200lb 6'4 racer, nor am I racing the bike at all.
I'm just kind of looking for opinions. I know most people will say it's a bad idea and what's the point and bla bla bla, but I like how it looks, the detail of it, and would like somebody to either affirm that it's not significant enough to harm the integrity of the cranks, or that for sure I'd end up breaking them because here are 10 pictures of vintage fluted cranks that all broke down the arm.
Just to make sure it's clear, I wouldn't be drilling around the pedal holes at all, nor anywhere that isn't already fluted. And the holes would be small, just like in that Campy crank