Well, I think it's high-time I finished this series - don't you?
*** Cross References to the other two supporting threads:
Drillium How-To Guide Part One (Stripping Anodizing)
Drillium How-To Guide Part Two (Filing and Sanding)
I use a muti-speed Dremel, currently a model 300. I've tried singe-speed versions and left myself with lots of clean-up after drill bits wandered on me at high RPM! It's nice - and imperative if you're just starting out - to have low speed for more control. Higher speed is great for boring straight through quickly and easily, however, the layout/pilot hole work is best done at low speed.
A phrase I've heard since day one in the Navy applies here: "Pre-Prior-Planning Prevents Piss-Poor Performance" (referred to as the 7 P's). After all, you can't put material back once it's been removed, right?
So, I take a Sharpie and experiment with different ideas before deciding upon a pattern and then drawing it directly onto the part in question. Today we're doing a pair of Campagnolo gear levers to add a further little bit of bling to Shnibop's Colnago Super.
Pattern drawn and ready for drilling:
Next, we simply chuck in a fairly small-diameter drill bit (I use a 3/64) at low speed to drill our pilot holes for the larger diameter drill bits at high speed. Then, simply drill a series of pilot holes into the stock you're using - I only drill in about 5mm or so - I've broken off drill bits here and there and it's no picnic getting them out, let me tell you!
Pilot holes drilled:
Now, I simply go up a couple drill bit sizes and bore completely through with each successive size. Yeah, a drill press would do this in one go - and I'd have the option of larger drill bits, too - but where's the fun in that?
Successive drillings completely through:
Note how I get the drillings as close as I can to each other; in this case, it's to ensure I don't have too much material left over that I'll have to get rid of using my "Dremel as router" technique.
We're almost ready to finish the rough opening:
Okay, now we have our basic cut-out ready for a rough-finish. How do we get that extra crap out of there?
On to Post #2 for the answer