u/cyrtex

I need a CNC machine to drill holes in long rectangular aluminum tubes (0.8mm wall thickness), up to 8ft / 2400mm long, with 0.7mm accuracy. The profiles are up to 2" / 5cm wide, so I don't need a huge X and Z axis. Is it viable to extend the Y axis to such long size in a low-cost CNC like 3018? I'd imagine I'll have to use something other than a lead screw for Y axis motion because such a long 8mm screw will sag under its own weight? The maximum budget is $3000.

Edit: I need the process to be fully automatic. The tubes have different size and shape, and being able to process multiple tubes by laying them next to each other would also be nice, this is why I want to use a CNC.