Originally Posted by
ger21
It probably wouldn't be able to drill steel. The drills on those machines are typically pneumatic, and can't apply enough pressure. The RPM is probably much too high as well.
I use a machine like that every day.
I would not use rails that used an 8mm bolt, they would be far too large.
Typically, you'd want a 20mm rail which normally uses a 5mm bolt, and will have a 6mm hole.
I'd make a template from 3/4" MDF, with plastic laminate on both sides. This will keep it from warping, so the holes will stay in line.
I'd drill 1/8" or 3mm holes, and then drill the same size holes in your frame.
Then go back and enlarge them to the proper size for tapping.
Because you have ±0.5mm adjustment, you should be fine.