Drilling extruded enclosures with no removable baseplate

[fuzzmonger]

Howdy,

I've got myself some gorgeous extruded enclosures from china for fuzzmongery and a thought just occurred to me - as these are four-sided with no removable top / bottom piece, how on earth do I use my long stepped drill bit without drilling through to the other side?

Are there any 12mm drill bits that'll go through 2mm aluminium without the long taper / steps?

-Fuzzmonger

[EATyourGuitar]

this seems pretty obvious but have you tried a 12mm drill bit?

http://www.amazon.com/Speed-Metric-Jobber-Length-Drill/dp/B0006FIAMY/ref=sr_1_1?ie=UTF8&qid=1360177916&sr=8-1&keywords=12mm+drill+bit

[scuzzphut]

Any link or photos ? I'm having a hard time imagining how you'll get the PCB, pots and switch in there without a removeable lid 

[fuzzmonger]

Bit like these things - an extruded box-section with removable sideplates. Little harder to work with but it was good enough for Carlsbro pedals and the Fender Blender.
http://www.aliexpress.com/snapshot/215046605.html

Yeah, seemed like the obvious answer to me but I wanted to find out if you could drill a 12mm hole without drilling a series of smaller holes first. Any thoughts?

-Fuzzmonger

[slacker]

I use an ordinary 12mm drill bit, works fine just drill a small pilot hole first to centre it.

[samhay]

I use a 10mm and 12mm drill bit all the time. It is advisable to drill a pilot hole first - perhaps 2.5mm - but otherwise I don't drill the hole out in increments.

Edit: Slacker beat me to it.

[senko]

Your drill press should have a depth limit guard that allows you to drill at maximum only one layer

If you're not using a drill press (highly recommended), I'd suggest doing the pilot hole technique. 

[boogietone]

Pilot hole even with a drill press helps.

[senko]

Also, using an expander step bit (not sure of the exact nomenclature) works great with pilot holes.  Absolutely magical!