abbey road d enfer said:
That's how mine is.
That would work but it seems like a awful lot to keep track of and arrange. You still have to clamp, unclamp, clamp,unclamp, unless you have a cross slide. Maybe I’m missing something.
You don't need to clamp. The vice is not fixed to the table, it's free. Due to the added inertia, it never goes spinning. You just need a moderately firm hand.
I agree with Abbey on this in that a good quality drill press is probably the most useful tool you can get if you are doing a lot of metalwork.
I have also been formally trained in metalwork and wood work and there is a technique called 'touch centring' whereby having centre punched the centre of an intended hole, on the drill press you bring the drill tip down gently and slowly to just touch the centre dot: the drill will then self-centre and you can then apply pressure to drill through. It takes some practice so experiment, but it avoids having to clamp the metal sheet down.
I was also trained to use a sacrificial block of wood under the metal when drilling sheet metal as it absorbs vibrations and stops you drilling into the drill plate.
Don't forget that when you have your sheet centre-punched up, write the intended size of the hole near it with a marker - it save tears later when you drill the wrong size hole.
Another tip is to use small drills to start you hole and then work up in increments of 3 to 4 mm ending on a size that is 1 to 2 mm below the final size, then use the end size. This will give you a clean edge if the drill is sharp and prolong the life of your larger drill bits as it is the drill point that takes the most wear and smaller drills are cheaper.
When using a step drill, you can 'step-drill' out a block of wood first and then use that under the work piece. Your next best friend is a de-buring tool to clean up the edges of you holes and a small grinding wheel to keep your drills sharp, although bulk buys of twist drill are so cheap nowadays that they are almost throw-aways.
One of my fonder memories of metal work is using Engineers Blue, which is a kind of blue dye mixed with alcohol. The smell was intoxicating. The idea is that you paint it on the metal and then use a scriber to mark out you work so that it gives a contrasting colour to work with. You can also use it for showing the degree of fit of two fitting metal pieces.
Cheers
Mike