Well, the first question should always be....what do you
want to make?
(Yep, you mentioned that...
That'll decide how much $$$ will be needed to accomplish that
How much $$$ is available will determine how 'Good' of components,
materials, quality of parts, etc can be used. It matters.
But....there are a lot of ifs, ands, and buts....
IF...someone is very good with mechanical things then they can
cobble something together from complete junk. How well that works
is decided by how 'Good' someone is with the mechanical aspects, and
it also depends a *Huge* amount of what sort of tools they have
access to. And how well they know how to use them.
Making a design in CAD can often be a bit of a problem. There
are very few real-world materials that are anywhere near as flat,
round and square as the *Perfect* lines and elements that CAD will
draw out for you. So those parts need to be specially machined
very, very often to work correctly....or some type of mechanical
compensation accounted for to make corrections. Experience goes
a long way. But you can't get experience without trying. Failures
should be seen as finding out what Doesn't work....and knowing
what doesn't work can often be as...if not more...important as knowing
what 'Does' work.
(Knowing what does Not work can be directly attributed to the fact
that many of us still have fingers and hands to try something else with..
Getting back to your question....
If you want to actually *Use* a machine to Make Things, you're very likely
much better off to buy one.
It's not likely at all your "first design" will be good enough for you
and it's easy to get to a point of still working on design #2 years
later. You'll see tons of things that should'a-could'a been different
from design #1. You may end up with piles of hardware from Ebay that
are for design #3....when/if you get time.
The "bought" machine has been time tested and is known to work to the
standards it's built to. There are different levels. Basically, what may
be easily recognized as "hobby", "commercial" or "industrial"...just to
simplify for the sake of the discussion. Those levels should obviously
imply very different levels of *Cost* that are involved.
You may not know for sure if your DIY machine even works right with
nothing to make a comparison with. The bought-machine should come with
the very important and valuable....support you'll want...and need.
Well, someone has to make an initial design that works correctly...and
reliably enough to reproduce. And support it. That takes a lot of time
and money. Actually *Much* more than a lot. It's not easy...
DIY is a lot of fun, but it can get as addictive as any other thing.
The quality of whatever it is someone wants to end up making will depend
greatly on how good they are with the mechanics of things, how good
their tools are, their material choices, their design, their funds...($$$!).
A cnc machine implies a thing that's capable of doing very accurate
and precise work, so how accurate and precise it can do the work depends
on how well it's initially built.
If I needed to produce parts, and time was any factor at all, I'd join up
on the support groups the machine makers maintain and ask questions and
look at what others have done with that particular machine.
Many of us here love the challenges involved, though. Perfecting, adjusting,
tuning, upgrading. Those are all things that can take away from actually
Personally, I'm in the middle. I like making machines, but it's much more
sensible to just buy one if someone needs their parts/product anytime soon.
It's good to keep in mind, that it'll also take time to learn to *use* the
machine and make your parts to your desired standard. That's even more time
If you need aluminum parts, You'll need a "better built" machine. You'll
need a good design and some Good tools if you go with DIY. Access to a lathe
and mill and the know-how to use them can't be underestimated. But, then again,
someone who's really good with mechanical things can make something that works
great, from trash bins.
DIY or Buy...?