A viable mini-ish-mill build, or a hiding to nothing..?

Could I hear your opinions on this mini-mill design I've based on this video I spotted on the tubes:

http://youtu.be/05SpQC6ga-0

Here's what I've come up with - it's very similar, just with a widened stance and with an SHS frame.

Attachment 9180 Attachment 9181

http://youtu.be/q9pENBoOuYQ

(The Z axis isn't placed correctly as yet, need to work it out properly...)

The footprint stands at 600x430mm and the cutting area is around 150x200mm (it would be 200x200 if I could hang the spindle out directly over the centre).

Specs as follows:

20mm Ecocast plates.
Nema 23 motors all around.
20mm TBR supported rails.
16mm ballscrews (5mm lead).
Spindle would be one of those neat little Makita RT0700 things.

The heaviest task I'd want to throw at it would be to cut profiles in aluminium up to 20mm thick. Not fussed about shallow cuts.

Of course, I've got another build in the pipe-line but this one's appealing for a number of reasons, the main one being that the gantries are quite self-contained and fairly straightforward to put together. What I'll probably do is laser cut a couple of drilling templates in 6mm acrylic and then transfer punch into the ali plate before drilling out/tapping and fitting the ready made mounts/bearings - in other words, there won't be any expensive plate milling to do.

So, the question is this: provided I do a good job making it, is this a viable build, or an expensive hiding to nothing...?

Cheers!

Give Tweakie a shout as he has a similar build. I think he frequents here?

Tweakie, Tweakie.CNC, CNC, router, mill, engraver, vinyl cutter, laser.

An excellent link,

Cheers Swarfing!

Wal.

I prefer Tweakie's build myself even if it does involve a bit more welding.