"DoN. Nichols" wrote in message
...
Try to find "Modern Machine Shop Practice" (I forget whether
that last word should have an 's' on the end. :-) Don't confuse it with
"Machine Shop Practice" by Moultrecht which is a two-volume set. It is
a good book set to have, but you won't find it for free.

Who is the author?


Hmm ... check your drill press. Put a round tip piece of stock
in the drill chuck, put a flat piece of metal on the table, and bring
the round end of the rod down on the piece of metal. Look carefully at
the point of contact as you apply pressure. A lot of relatively
inexpensive drill presses flex -- both the arm supporting the table and
the head. This results in the contact point skidding towards you. This
applies lateral force to the point -- and with the skinny point of a
1/8" center drill and it *will* break. A higher speed means that you
are less likely to apply as much force to the spindle feed levers.

I did not know that test. Will do.

Very soft can be a problem -- it gums up the flutes of the bit.
360L brass has lead in it and is a bit harder than normal brass, but the
lead lubricates the cuts, so it is a very nice machining material. Cast
brass is more likely to be too soft to machine well.

But its overwhelming redeeming quality is that it is cheap.

I have a couple of power supplies - one should give steady 5 amps which
as
it turns out may not be enough. The other one should give 20 amps. I have
not tried that one yet.

But with an automotive battery, it would keep the battery
charged, and the battery would handle the current to start the motor.
(Of course, it really needs to be something like 14.4V to fully charge
the battery.

13.7 V both of them. And a charger somewhere in the garage. In the end this
is the way I may have to go: The first PS shuts down at start-up. I haven't
worked out if it is the normal protection kicking itn at 7 Amps or a fault.
I am measuring the current with a clamp meter and it does not even get up to
1 Amp. However, the protection is probably faster than the meter response...

Anyway, that part has been put off for the moment: Today was the day to try
applying a green patina to brass and soldering a brass ball to a candlestick
cup.
It is so easy to get distracted by things that are not immediately relevant
but fun to play with...

--
Michael Koblic,
Campbell River, BC