By way of encouragement(ish) I'm also scratch building a mill (main frame from 180x180x16 steel box section) as shown in its very early stages on the final posts here:

In contrast to the thread title this has morphed into a stand alone CNC mill, approx travels 400X x 200Y x 200Z (yup I know more Z would be good) which is aiming for an accurate, good finish in steel. Linear rail all round and 25mm ballscrews. Will initially be stepper powered but I am building with a view to changing to servos later - have already scrounged some. Spindle probably to be ER32, driven by a 2HP AC motor with VFD, with pulleys to vary speeds if need be.

Note the dates on that thread... but I've been only getting small amounts of time (and money) to go at it. I have also temporarily lost my CAD facilities which is not helping (due to my Alibre version not liking Windows 7 - but I'll be freeing up an XP machine as an offline CAD-only computer in the next few days I hope).

So anyway, I decided not to post further updates until I have some serious progress to show in the metal. That should be soon :-)

Reasons for the scratch build rather than adapting or refurbing were for me:

- I only have a floorspace of approx 1m x 1m where it can go, and that has to include computer and control box. So I wanted to make maximum use of the space. So there will be a (very robust) stand with space under it for computer and electronics, and on top goes the machine, with the column barely clearing the ceiling.

- Refurb projects/machines tend to be a LOT bigger than that unless you're talking a Denford or the like, and even these are usually wider (so won't fit). Often the more serious machines also take more electrical supply than i have available.

- I have recently not had much money at all to spend on this project. DIY lets you scrounge bargains. For example, the metal for the frame and stand has been approx:
GBP 60 for the main beams (approx 2.7m long x 180mm square x 16mm wall) inc. cutting.
GBP 22 for beams for the stand (2 off approx 2.5m, 160x80x6mm rect. section, unfortunately galvanised)
GBP 40 for more beams for the stand (2 off approx 2.5m. 100x50x5mm rect. section)
GBP 15 for apprx 2m of 150x150x10mm steel angle
Plus some bolts, epoxy, welding rods, paint, sand etc. and petrol for collecting.
Still to buy are a few heavy steel plates. For mounting rails on and for closing tube ends.
So maybe GBP 250 for the main 350 kg+ (before sand filling) structure. Plus a lot of time of course, including grinding back that galv before welding the stand. And a few tools e.g. cutters knackered when cleaning up ends...
Still not bad. But it did take some time and luck to find those bargains. And when you count in linear rails, ballscrews, servos etc. gathered so far, even at ebay bargain prices I'm definitely into four figures for cost so far. One day I'll add it all up...

- But it's a challenge! And it will be very cool when finished :-) I'm really looking forward to the 'fun' bits - mounting linear rails and ballscrews, and seeing motion... But there seems to be a LOT of slow progress building the frame first...

As Jazz says further up the thread if you want to get up and running in a sensible time don't do what I'm doing - at least not unless you can dedicate a lot more time to it than I've been able to. Only really worth considering a scratch build if it's just a hobby and there's no real urgency (as in my case). You'll also want some reasonably large and rigid machines already to work on unless you plan on farming things out.

The results are not assured either - will my machine when eventually finished really work any better/faster/more accurately than e.g. a Denford Triac refurb? Could probably just about have bought one of those for all that's gone into it so far...