For a couple of years I have been thinking that a CNC*machine would be a good tool to have. My main tasks for it at the moment would be PCB production, and cutting ribs/formers from balsa/ply for model aircraft. So I reckon that 6" X, and ~2" Z (vertical) would be enough (minimums) for this task?*Their are rare occasions where formers could be larger than this, so I would have to cut these by hand again.
I am making the assumption that the ?spindle? for cutting the material could be the same in these tasks, but possibly would need to be variable speed, and capable of (manually) changing the bit (between wood types and copper metal). I assume that for these 2 tasks, 3 Cartesian axis would be enough?
1) How long should I get the Y axis?
My guess is that you cannot do a partial cut, then turn the piece around to do the other side! Most woods come in either 3' or 4' lengths. Should I get a system to accommodate a 3' length and then move the wood for the rest of the cut, or should I aim for the longest length possible (i.e. 4').
2) For a 3 axis machine above, what else could it do?
If the spindle was variable speed, could it handle doing (what I believe is called 2+1/2) wood carvings, things like picture frames etc. if they fitted within the dimensions?
(hopefully up to this point things are still making sense)
These devices seem to be quite expensive on the whole. I guess that although the materials might be 'relatively' cheap in themselves, they need to be precision made. My metalwork/woodwork skills on this scale are probably not up to the accuracy required, so I would be looking at getting some 'kit's of axis sets [if such a thing exists, a different kit per axis to make the shape you want?] rather than building from scratch scratch, or a completed unit. What worries me, are people who state that it has taken them 3+ years to get them working. If I had a device working, I know that I would use it, but I am concerned that I would get down-hearted after 3 years if it still didn't work! Is this length of time usual?
3) The wishful thinking question
Is it usually possible to add the 4th axis to a machine? What would be required for example to be able to machine pieces suitable for a model helicopter? Would this also require the 5th axis, and would the 'spindle' need to change?
Edit:
One last question. I am in the UK, are there /good/ and /cheap/ places in the UK to obtain materials from, or am I best importing items?