Measure twice (or more), cut once, use some kinda guide to help keep it straight, go nice and slow, nice and steady, use a blade with lots of teeth … what could possibly go wrong ? Cutting whilst the forks are on the bike is more of a challenge, but still perfectly doable.
(All that said, I feel it’s only fair to confess to having used a disc-cutter in the past, then tidied it up a bit with a couple of files.)
Carbon is weird stuff to cut – I don’t like the lack of resistance, and there’s no feedback in the blade, plus it does that creep self-lubricating thing with it’s own dust too … I keep a very close eye on any cuts in carbon.
Steel on the other hand is lovely, it’s a material that makes perfect sense, decent steel has a grain you can feel when you work it, and it flows in a very predictable way. Much prefer steel as a bicycle material, and for all kinds of reasons.
@ muddydwarf – yeah, I can see how that’d make you feel …