Originally Posted by
aarggh
If you have any ambitions or aspirations towards CNC or producing any sorts of products, I would consider the 3040 a fairly useless machine. It's cheap for a reason, most of the ones I've seen are quite reasonably made but usually have vastly inferior components, such as ACME (in well designed, quality machines ACME screws are good, just not in these units) or even trapezoidal screws, unsupported round rails, a woefully underpowered and crappy DC brushed spindle, etc, etc.
What happens at first with these machines as you have pointed out, is most people buy them with the expectation of easing into the cnc world, but what ends up happening in the real world is that when bought, the users very quickly find out they've spent an awful lot of money for an underpowered machine with bad tolerances, and end up forking out an even larger amount to get a more appropriate machine. Rendering the smaller one a paperweight, albeit an expensive paperweight.
The resale value is next to nothing, so you'd have to ask yourself if it's at all likely you'd be getting serious about cnc, and if so, are you prepared to write off the 3040 if you end up deeming it not suitable, or you'd still have a use for it?
Personally, I don't see any benefit whatsoever of the 3040's over the 6040's, they are cheaper, but the 6040's are a completely different beast. Most come with VFD/spindles, supported round rails or even ,linear rails on some, far more robust construction, and proper ballscrews. But thats my opinion.
cheers, Ian