Sherline Lathe User Guide and Specifications

Initial Test Cutting
If you have never operated a lathe before, we suggest that you make a trial cut on a scrap
of material to learn the operation of the machine. In a 3- or 4-jaw chuck, secure a piece of
round aluminum stock approximately 3/4" (19mm) diameter and 1-1/2" (38mm) long.
Secure the presharpened 1/4" square cutting tool supplied with the lathe in the tool post,
making sure that it is properly positioned. Turn the speed control all the way
counterclockwise, and then turn the motor on. Bring the speed up to approximately 1000
RPM (about 1/3 speed). To establish tool position in relation to the work, bring the tool in
slowly until it just starts to scribe a line on the work. Crank the tool towards the tailstock
until it clears the end of the work. Advance the tool .010" (.25mm) using the crosslide
handwheel (10 divisions on the inch handwheel scale). Using the bed handwheel, move
the tool slowly across the work toward the headstock.
Cutting tools used on lathes are designed to remove metal much as paper is removed
from a roll. It takes a positive feed rate to accomplish this. If the feed rate isn't fast
enough, it would be similar to tearing an individual sheet of paper off the roll. The results
when cutting metal would be shorter tool life, a poor finish and tool "chatter". Chatter is a
function of rigidity, but it is controlled by speed (RPM) and feed rate.
Since you already have a piece of aluminum chucked up, experiment with speed and feed
rate. You just took a cut of .010" (.25mm) and probably noticed that the machine didn't
even slow down in the slightest. Now take a 1/2 inch long cut .050" or 1mm deep, which
is 1 revolution of the handwheel. If you used the sharpened cutting tool that came with
your machine it should have made the cut easily. If the tool "squealed", reduce the RPM a
little and take another .050" cut while feeding the tool faster. You will probably be
surprised at how easily your machine takes cuts this heavy.
We will now purposely try to make the machine "chatter". Make sure the stock you are
cutting is sticking out of the chuck no more than 1 inch (25mm). Crank the handwheel
two turns further in from the last setting which will give you a .100" (100 thousandths of
an inch) or 2mm cut. Set the spindle speed to about 1000 RPM (1/3 speed) and feed the
tool slowly into the material. Vary speed and feed until you get a substantial chatter.
Without changing the depth of the cut, drop the speed to about 200 RPM and feed the
tool into the work with more force. The chatter should disappear. Once you have learned
to control chatter by adjusting speed and feed, you will be on your way to becoming a
machinist.
Holding the Workpiece
Work can be held between centers, in three- or four-jaw chucks, on the faceplate or with
a collet. Sometimes it is necessary to use a chuck and center, and, if the work is spinning
fast, a live center should be used. (See Figures 3 and 4.)