In a separate thread, Turning Small Diameters, I asked about the capabilities and characteristics of lathes for small scale (2mm railway) model making, and received excellent guidance. At the end of that thread the topic got on to milling machines, and as it was already quite large, I have started a new one to ask similar questions.
So, materials at small scale will often be quite thin. 5 thou to 40 thou (0.12mm to 1mm) brass would be quite common. There's probably little need for a milling machine for very thin material, and if I get a mill it would most probably really be for thicker stuff, but anyway I am intrigued to understand what is realistic on the sort of mill that I might get - around
50Kg weight or less (important to me), and probably £500 or less. I wonder if I would ever use the mill on these sort of materials.What is the thinnest material I can realistically expect to mill?
It may seem impossible, but I know even less about milling than about turning. But I suppose the operations to consider are edge-milling a shape on thin sheet, and surface milling thinner areas. I guess there may be techniques for handling thinner materials like laminating with something thicker?
To get slightly off t>BTW, and back to your original question, I think you would find a
Mills in my size range seem not to have a knee at all - which I assume is the component that moves vertically on the column and supports the milling table. The table just rests on the base, and all the Z-axis movement is achieved from the milling head movement. Any mill I would consider would have a square column. The mill I have looked at most is the Sieg X2, basically because that's the one covered in depth on the excellent mini lathe site that is my main source of info (minilathe.com).
But I don't really understand your point. I assume you are talking about maintaining X-Y position after Z-axis head movements - unclamping a head on a round column would allow the head to rotate and lose position? But even the little Sieg X0 type micro mills, with a round column, use some sort of racked arrangement for Z-axis movement that I assume retains X-Y position? I must be getting the wrong end of the stick, as usual.
Chas