On 2008-12-22, Michael Koblic wrote:
DoN. Nichols wrote:
Well ... the motor on mine is an inexpensive motor, and you
should be able to pick up a used motor with half the speed for not too
much. The main thing is that you want one with the same diameter
shaft, since you can't bore the motor pulley out to a larger size
with the lathe without a motor. :-)
If the lowest spindle speed with a 1750 rpm motor is 525 rpm then half-speed
motor (875 rpm - 8 pole) will still get me 260 rpm (give or take) - still
pretty swift. BTW quick search shows that such motors are a) rare as hen's
teeth and b) expensive. To me it would make more sense to strip a treadmill
or something and use the DC motor with speed control. Or buy the mini in the
first place :-)
The use of treadmill motors is fairly common. There used to be
a treadmill motor and controller offered by a surplus house, and one
common modification was to eliminate the safety feature (for a
treadmill) of requiring the speed pot to be turned down to zero before
it would start. Obviously a pain with a lathe. :-)
Right now it is 3.5 degrees C in my "workshop" and I do not really
want to be there :-).
I can understand that. About 38.2 D -- kind of nippy, though
better than -40. :-)
But that is still better than -80. Everything is relative.
Agreed. The reason that I mentioned -40 -- without telling
which measurement system -- is that -40 is the only temperature at which
it does not *matter* which system you use. K and R are eliminated,
because they both start at absolute zero, so negative values don't
exist. C and F are the same temperature at -40. :-)
Do you know many
workshops with ambient temperature of -40? I know that when Russians
evacuated all their heavy industry during WW2 to the Urals some of the
factories operated without roofs. But that is probably extreme and a major
difference between a hobby and getting shot by the KGB (sorry, NKVD then)
for refusing to work on the thin pretext of being frost-bitten.
:-)
[ ... ]
I wonder what there is in the gagage that is going to freeze...
At 3.5 C? Nothing likely. But get colder and ...
Anti-freeze*? :-) Glues? The epoxy itself? Oil should have no
problems, though grease can get thick enough to do no lubrication for
a while. :-)
When I was young and living in a bed-sitter one way of telling room
temperature first thing in the morning was to observe natural phenomena.
Breath begins to condense at about 12C. Below 4C the cooking oil (at least
the English cooking oil of yesteryear) is reluctant to flow out of the
bottle.
Hmm ... I was in the shop this afternoon -- and my breath was
not condensing. I had an electric heater by my feet running to keep the
feet a bit warm at least -- and presumably the somewhat warmed air did
come up past my face, but I did not notice that. :-)
But the waylube was noticeably stiff in the surface grinder
table. I was working to thin down some open-end wrenches so they would
fit the tap chucks on a couple of TapMatic tapping heads. I now finally
have a full set of wrenches for the two sizes. (Of course, they should
have come with the heads -- if I had bought them new. -- But those would
be cheap stamped steel wrenches anyway. These were forged steel ones
which simply had too thick a head to fit in to the milled flats.
Enjoy,
DoN.
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