In article ,
Paul Farber wrote:
I'm a hobbiest just starting out, so I really don't want to throw a lot of
money into a mill for a few years.
I've been looking at low end mills (some import, some domestic) and one
thing that I've read about is freeplay on the shafts. Most that i've
fiddled with seem to have almost 1/4 turn of the shaft before the gears will
start moving the table. Is that normal?
What gears? Normally the handcranks turn long screws in the
tables, with a nut mounted to the saddle for both the X and Y axis. No
gears involved on a vertical spindle mill -- unless you have an electric
power feed between the handcrank and the end of the table. For some
horizontal mills, there is a power takeoff from the spindle motor or from
a secondary motor run through a telescoping shaft and universal joints to
turn the leadscrew.
As for the backlash -- that is attributable to wear in the
threads -- but there are often adjustments for that -- and some amount
of backlash is inevitable unless it is so tight that it is difficult to
use (unless you have ball screws and nuts, as is common in CNC
machines), so normally people simply learn to compensate for that by
alway approaching from the same direction, so the backlash doesn't
count.
For less than $1000-$1500 what low end mills are 'pretty good'?
Hmm ... it depends on luck, but I got my Nichols horizontal
spindle mill for about $200.00 from eBay -- and nearly as much more for
shipping. (It weighs about 1100 pounds.) I later got a vertical head
for it, so I can use both formats.
If you want to see what it is like -- and what is involved in
bringing a really old one up to use more recent accessories (such as the
vertical head), you can visit my web page dealing with it.
http://www.d-and-d.com/NICHOLS-mill
Note that the company is long gone, but the equipment is sturdy and well
worthwhile.
There are others which will probably be as good, though I like
several of the features of the Nichols -- especially including the fact
that the horizontal spindle moves on vertical ways on the side of the
column (using a long lever connected to a sector gear).
Good Luck,
DoN.
--
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