Re: [CAD_CAM_EDM_DRO] Asian Import mills, EMCO, PRAZI, Myford, MOTORS

> Hi to the List,
>
> I've received some money, and I'm looking to buy a "big brother" to the
> Sherline mill. The ENCO, RongFu, Grizzly and Jet import mills are a
> possibly, however what I'm really looking for is a EMCO FB-2 mill. The
> EMCO's don't seem to be imported to the US any more. :>(
>
> I appreciate hardware like EMCO, Myford and Sherline (shows my limited
> knowledge), so I'm still leery of the Asian imports. What is the
> principle problem with the imports? Does replacing the lead screws and
> bearings, and doing a good alignment bring them up to spec?
>

My exprience is limited to sherline, the bridgports at work, and my
smaller Rockwell knee mill, however here's what I would look for in a
mill, in order of importance:

0) rigid setup... if the machine flexes when you cut, nothing else
matters.

1) A mechanism to change the head-table distance while maintaining
registration. Traditionally this was accomplished by putting the table
on a movable knee, but it can also be done by having a head that moves
up and down. What is important is that the head moves on ways that
can't rotate, so alignment is preserved. This is the principal
failing of the mills that look like overbuilt drill presses. If you
switch between an end mill in a collet and a drill in a chuck, you
will have to move the head or table to make up the difference in
length - and you may also have to do so to get clearence to install
and remove tools from the spindle.

2) A spindle quill stroke of 5" or so. Cranking the knee up and down
to drill deep holes (my Rockwell's quill only moves about 2") is
really annoying.

3) Large table travels - it's real annoying if you want to make
something and it won't fit on the table. Also, with a large table you
can keep a vise on the machine but clamp the occasional project that
won't fit in the jaws down next to it.

If you are thinking 3-axis CNC, then you need a machine without much
play in the quill fine-feed handle, or a knee that you can put a motor
on.

Chris

--
Christopher C. Stratton, stratton@...
Instrument Maker, Horn Player & Engineer
22 Adrian Street, Somerville, MA 02143
http://www.mdc.net/~stratton
NEW PHONE NUMBER: (617) 628-1062 home, 253-2606 MIT