@Dberndt:
1. The slides should be fine until they start to wear, then you may not be able to adjust out the slop without binding at the extremes of the movement. The backlash in the screws can be adjusted on some mills, but the same as with the ways apply.
2. I don't agree that milling aluminum requires less power and a less sturdy machine than steel. SS is a *****, depending on what kind it is. Some of them work harden so you just cannot take fine cuts. PCB engraving does not need much power, but high RPM and speed of movement is absolutely high on the wish list. I suggest you etch the board using laser transfer, and use the mill to drill the holes.
3. For a small mill, I'd drop the flycutter, it needs a beefier machine or it will very easily chatter. But you should not mount your cutters in a drill chuck! It will creep out of it as you work. I suggest a collet chuck.
4. Browse the forums here. This can't be answered easily, and it depends so much on your needs, preferences, budget and lots of other factors. My suggestion is you start out learning G-code basics first while you look around. It will not be a waste whatever program you choose. Since you're a programmer, I think you would be able to do many simple tasks by just feeding Mach2 the codes as you go instead of turning the handwheels.
@Alpay: You don't say what you will do to those 12"x12"x1" plates.
Since you use 1" plate, I suppose you want to remove quite a bit of aluminum, at least on parts of it?
If that is the case, you will need quite a bit of patience using a Taig or similar size! Unless you just want to round the edges it seems to me you will be carrying out many buckets of swarf, and need a lot more grunt to make it.
Other options are casting it, pressing it or hydraulic shaping from sheet metal. A friend showed me a prototype aluminum cover cast in plaster, and it looked like it was die cast. Very straight, smooth and with fine details. For casting you could mill your master from CibaTool or a similar plastic. Then you can go really fast even if you don't have a powerful machine.  |