Sherline 5000 Mill Assembly Instructions

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Remember that unless you drill very small holes (less than
1/64") or turn a lot of long shafts, you are giving up a very
useful feature to solve a problem which can usually be
handled with a few passes of a good mill file. The inaccuracy
inherent in any drill chuck is such that perfect machine
alignment is meaningless unless you use adjustable tailstock
tool holders.
SQUARING UP YOUR MILL
The following tips are taken from the Model 2000 mill
instructions. Though the 8-direction mill is shown in the
examples, the same procedures would be used for aligning
the 5000-series mills, or any mill for that matter.
FIGURE 16—The axes of movement of a Sherline 8-
direction mill. Table left/right movement is referred to
as the X axis. Table in/out movement is the Y axis.
Headstock up/down
movement is referred
to as the Z axis. The
headstock can also
be rotated on its
saddle on Sherline
mills. The four
additional move-
ments available on
the model 2000 mill
are also shown
above.
Determining the level of accuracy you really need
Squaring up a multi-direction mill can be a chore if you
want “perfection.” It is best to determine how accurate
the setup must be before you start. The larger a close
tolerance part is the better the setup required. An error of
.001" (.025 mm) per inch (25.4 mm) would be a very small
error on a part .4" (10 mm) long. However, a part that is 5"
long would have an error of .005". The type of machining
that is going to be performed also has a bearing on the
quality of the setup. As an example, a drilled hole doesn't
usually require the quality of setup that would be used for a
bored hole, (assuming the hole is being bored for accuracy
rather than for lack of a drill of the proper size). The amount
of work that will be done with the setup should be
considered too. If your setup is just to do one particular job
you only have to set it up close enough to do that job. If the
setup will accommodate future operations as well, it should
be adjusted to the tolerances of the most critical job. For
example, squaring up a mill and vise to work on a number
of precise parts is worth more of your attention than setting
up to drill one clearance hole in a non-critical part.
Limitations of the production process
Before starting you should realize that these mills are
relatively inexpensive machine tools. They have accurately
milled slides but the surfaces are not ground. To increase
the accuracy of a Sherline tool only a percentage point
would dramatically increase the price. We try to give a
customer what we consider "the most bang for the buck."
Why aren't there alignment pins to square up the machine?
If you are a novice to machining, you probably believe a
machine should be designed so that a couple of pins could
be dropped into holes, squaring up the machine and
eliminating this whole process. After all, that is the way
they do it with woodworking machinery. The truth is the
tolerances that work well for wood cutting tools simply
aren't accurate enough for most metalworking tools. You
just can't hold the tolerances required with "pins." When
they fit tight enough to lock the head square to the table
you can't remove them to do work that isn't square. They
become more of a problem than the problem they were
installed to eliminate. For example, an alignment or assembly
error of .010" in a wooden kitchen table will never be
noticed. Usually the floor it sits on is not even flat. It would
be a waste of time and effort to make it more accurate
than it has to be. On the other hand, a cylinder that has
been bored out of square with the crankshaft in an
automobile engine could wear the entire engine at an
alarming rate. The piston goes up and down a million times
in a normal day's use. The additional cost in fuel and
shortened life demands accuracy. Your Sherline mill should
be adjusted and aligned to the degree of accuracy demanded
by the particular job you are attempting to do.
Start by getting the column
close to square with the table
ALL SHERLINE MILLS...The first place to start is to get
the column approximately square with the table using the
pointers and laser engraved scales on the machine. The
first time you set it up you will have to use a machinist's
square on the side-to-side column rotary adjustment as the
pointer will not have been “zeroed in” yet. None of these
adjustments must be extremely precise at this point because
a finger type dial indicator will be used to make the final
adjustments later. Remove the headstock/motor/speed
control unit from the saddle. Place a machinist's square on
the table and line up the front of the saddle to get the column
approximately square front to back. Then line up on the
right side of the saddle to get the column approximately
square side to side. Reinstall the headstock assembly.
Check for any built-in error in your machine
ALL SHERLINE MILLS...(See Figure 17.) To check the
built-in error of the machine use a dial indicator mounted in
the spindle. Move the table under spindle with the Y-axis
handwheel and note the error. This error will usually be
around .001" to .002" (.05 mm) in 3" (76 mm). (Remember
the components are not precision ground, they are precision
milled.) When squaring the head later on this error should
be accounted for. Remember you are squaring the head
and spindle to the base of the machine where the saddle
travels, not the surface of the table itself. The head doesn't
have to be square for this operation as long as you don't
rotate the spindle since you are only checking for square in
one direction.
X
Y
Z
4
5
6
7
8
Questions? See our “Frequently asked questions”
section on the web site: www.sherline.com/faq.htm.