Sherline 5000 Mill Assembly Instructions

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finish due to the small length of tool edge in contact with
the work. This ridging becomes more pronounced with rapid
feed. To provide a smooth finish, the sharp cutting point
may be slightly rounded with an oilstone, taking care to
preserve the side clearance underneath this corner.
This type of tool should not be advanced directly endwise
into the work. The depth of cut is set while the tool is clear
of the end of the work. The starting procedure is to advance
the tool until the point just touches the work. Note the reading
on the crosslide handwheel, withdraw the tool slightly and
move along until clear of the end of the work. Now advance
the crosslide to the above reading, add desired depth of cut
and then feed the tool along the work piece the desired
distance. Withdraw the tool clear of the work, having noted
the reading on the crosslide handwheel. Mentally note the
reading on the leadscrew handwheel, return the tool to
starting position and advance to the previous reading plus
the desired cut.
NOTE: Sherline offers optional adjustable “zero”
handwheels that allow you to reset the handwheel to zero
at any time...a handy feature normally found only on larger,
more expensive machine tools. New tools may be ordered
with them already installed, and existing tools can be
retrofitted with them on any axis.
The second feed is now commenced, stopping at the same
reading on the leadscrew handwheel as before. This
procedure enables turning to accurate length.
Repeat the procedure until the work has been reduced to
within about .010" (0.25 mm) of desired diameter, noting
that each .015" (0.4 mm) increase in depth of cut will reduce
the work diameter by twice this amount; that is, .030" (0.8
mm). For the finishing pass, advance the tool by the required
amount and feed along the work just far enough to gage
the finished diameter. Adjust depth of cut if necessary and
complete the final pass using a SLOW feed to obtain a
smooth finish and exact size.
USING THE CUTOFF OR PARTING TOOL
(See Figure 37.) After completing a part in the lathe, it is
frequently necessary to separate the part from the excess
material used for chucking. This operation is best
accomplished with the use of a cutoff tool or “parting tool”
as it is sometimes called. The Sherline cutoff tool and holder
utilizes a very slender, high-speed tool steel cutting blade
mounted in a special tool holder. The thinness of the blade
(.040") enables it to feed into the part quite easily and at
the same time minimizes the amount of waste material. A
word of caution: Never use a parting tool on a part
mounted between centers. The part may bind on the
cutter, resulting in a scrapped part or a broken cutting tool.
Always try to lay work out so the cutoff tool is used as
close to the spindle as possible. Set blade height by sliding
the blade back and forth in the slightly angled slot in the
tool holder. It should be set so the tip is aligned with the
centerline of the part being cut. An unusual diameter may
require a shim under the front or rear of the holder to
accomplish this. The tool can also be mounted on the back
side of the table by using the rear mounting block, P/N 3016.
IMPORTANT!
Always use cutting oil when using the cutoff tool. The
cut will be made much smoother, easier and cooler.
The turning speed for parting should be about one-half the
normal turning speed, and feed rate should be a little heavy
so the chip will not break up in the slot. If speed and feed
are correct, there will not be any chatter, and the chip will
come out as if it were being unrolled. Cutting oil plays a
major roll in this occurring properly.
If the tool chatters, first check to see if the work is being
held properly. Then decrease speed (RPM) or increase
feed rate or both. Once the blade has chattered, it leaves a
serrated finish that causes more chatter. Sometimes a
serrated finish can be eliminated by stopping the spindle,
adding a liberal amount of cutting oil, bringing the blade up
so there is a slight pressure on it without the spindle turning,
and then turning the spindle by hand or as slowly as possible
with the speed control.
Very small work may be completely cut off when held in a
chuck and allowed to fall onto the crosslide. It is too small
and light to cause any damage. Hollow articles, such as
rings, may be caught on a piece of wire whose end is held
in a suitable position.
SIDE TOOLS
While these may be, and often are, used as general purpose
turning tools, their specific use is for facing the sides of
collars and shoulders; that is, finishing these to correct
dimension and with a smooth, flat surface. They are also
for facing work held on a faceplate or in a chuck. The
facing of work in this manner is very useful for the
production of truly flat surfaces and for producing articles
to an exact thickness. The uses of side tools are illustrated
in Figures 33 and 36. The sharp corner at the cutting point
should not be slightly rounded, as may be done with the
normal turning tool, as knife tools may be required to produce
sharp corners.
FIGURE 37—A parting tool used to separate a part
from it’s bar stock.