Small Mill very early design stage

[Robin Hewitt]

Hmmm

Perhaps confidence is that feeling you get just before you understand the problem? :whistling:

I don't think you have to worry about heat quite yet. I suspect you are losing the plot and zooming off on a tangent.

You need a lot of iron and the cheapest way to get it is an older machine that you tart up. Scrape the slides, add ball screws etc.

It may seem a good idea to buy a shiny new wonder mill aimed at the CNC hobby market, but an older industrial or (better) ex-school machine is probably a much better bet, not so pretty but considerably cheaper and with more possibility for improvement.

I suggest you aim for 5 micron accuracy, the resolution of your everyday digi-caliper. You will then get 25 microns fairly easily. You will then realise 25um it isn't enough.

If you shopped with 5um in mind you don't wind up replacing the whole works like I had to.

Robin

[leadinglights]

Hmmm
...
I suggest you aim for 5 micron accuracy, the resolution of your everyday digi-caliper. You will then get 25 microns fairly easily. You will then realise 25um it isn't enough.
...
Robin

Hi Robin,

1 thou , 0.001 inch, 25 microns for the youngsters, is quite easy over a small distance with a well adjusted machine, but gets progressively harder over long distances. I have aimed at this over the 200mm by 200mm by 100 mm range, quite tight enough - and even if I get close it should be good.

I have rejected converting an old milling machine on a simple basis, space available is of the order of 1000mm by 600mm including access so say 600mm by 600mm.