Well Dr Watson, its wobbly metal.
Enough of the Tom Foolery and down to the serious business of an issue that must be fairly common. Drilling larger diameter holes in flexible metal sheet generally found on hobby cases. Just in case you were wondering though Tom Fool (aka Tom Skelton) is apparently a ghost of a Jester at our local castle, Muncaster so here's hoping he's had plenty of opportunity to wander round the house and grounds with odd shaped holes in his thin sheet metal parts.
A lot of trouble I have with when its time to put a project in a case is that the 16mm hole needed for an SO239 for example causes me no end of trouble. I have tried a number of different ways to make the holes without giving a figure of 8 or elongated hole. Step drills tend to give slightly better results that piloting and increasing the bit size. I have found that the latter can easily end up with a poor hole if any vibration is imparted into the case.
So what's the answer, well, I just don't know. Punching would seem to be a better solution as would routing the holes but in the case of pre folded sheet I'm sure this isn't too practical. I'm wondering if people have had better results with other ways of making these holes.
I share your bugbear here. I've got a very similar challenge to make a number of holes for SMA connectors in about eight tin plated enclosures for a receiver I'm building...and I've been holding off on making the holes. I think the punch is the most practical small scale solution; Greenlee make fabulous punches and electric drivers - and they would be perfect! A great example of the capabilities can be found here - http://www.youtube.com/watch?v=9HE-T9yAnhc . However Greenlee are pretty expensive in the UK, so I'm wondering whether Q-Max punches (all available from Lawsons, Farnell, Rapid etc) and a wrench would work - that would be the under 10 quid solution. I'm also hankering after a decent drill press or mini mill, although work holding becomes the problem then.
ReplyDeleteI've just this morning bought a 16mm hole punch and I'll have a go with that and see how I get on. I can't say I'll big review but I'll be reporting back. My metalwork skills are pretty poor at the best of times so if I can make a decent hole then I'm sure anyone can ;-)
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