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Sanding is easily
the most tedious woodworking operation. It can sometimes take as
long to hand sand a project as it takes to build it. Fortunately,
you have four sanding choices with the Shopsmith Woodworking System:
disc sander, drum sander, strip sander and belt sander.
In this tip,
we will concern ourselves with the disc sander. A disc sander can
help eliminate some of the sanding tedium. It can't be used to fine
sand, but it will remove saw marks from a ripped edge and smooth
end grains. It can also be used to bring a workpiece to its final
dimension, true-up joints and grind tools.
Sander Mode - Setup & Features
The acessories that are used for disc sanding operations are
the: (A) sanding disc and sandpaper, (B) worktable, (C) miter
gauge, (D) rip fence,and (E) extension table. The Model 510
Use the accessories
shown in Figure 17-1
for disc sanding operations. To set up your Mark V in the disc sander
mode, follow the instructions in the Owners Manual that came with
As you work
in the disc sanding mode, you'll find that the Mark V is an extremely
capable disc sander with several special features:
- The 12" disc
has a sanding surface of 113.04 sq. in.
- The rip fence
functions as a backstop when sanding long or wide stock.
- Without a
backstop, you can sand as big a workpiece as you can safely handle.
- The miter
gauge can be used to hold stock at the proper angle to the disc.
- The table
tilts from "0" to 45° right and the miter gauge can be adjusted
from 30° left to 30° right to sand at a variety of angles.
- The rip fence
can be offset to sand boards to a specific width.
- The quill
feed and feed stop can be used to sand boards precisely to a specific
- You can sand
without the rip fence or a miter gauge. This is particularly useful
when sanding convex curves.
A very practical
setup is shown in Figure
17-2. By mounting a second disc on the upper auxiliary spindle,
you can have two different abrasive grits available at the same
Mount a seond disc on the upper auxiliary spindle and
you'll have two different abrasives available. The extension
table supports the stock.
- The Model
510 lower saw guard accommodates the sanding disc. Connect the
hose from your dust collection system to the dust chute in the
guard for virtually dust-free sanding. For dust collection on
the Model 500, a special disc sander dust chute is available.
discs are available in three garnet grits: coarse, medium, and fine.
All three grits are open coat-only 40 to 60 percent
of the disc surface is cov-ered with abrasive material. This helps
minimize loading at high speeds and extends the life
of the disc.
The grit you
choose depends on the work you have to do:
grit will remove large amounts of stock quickly. It can be
used to bring workpieces to their approximate dimensions; however,
it leaves a rough surface. If you want a smooth finish, you must
follow up a coarse grit with a medium or fine grit before hand
grit will remove small amounts of stock and can be used to
bring workpieces to their final dimensions. It leaves a fairly
smooth surface. From a medium grit, you can go straight to hand
- Fine grit
leaves a smooth surface. It greatly reduces the time you need
to spend hand sanding, though some hand sanding will still be
required to remove swirl marks and obtain a perfectly smooth finish.Fine
grit can also be used to grind and sharpen tools. Caution:
When using the sanding disc on the Model 500 that's not equipped
with the special disc sander dust chute, place a wide scrap board
on the way tubes directly under the disc. Sandpaper continually
loses grit, and the board will keep this grit off the way tubes
where it could scratch them. If you don't use a board to protect
the tubes, be sure to clean the tubes thoroughly after you finish
your sanding operations.
Before using the disc sander, read and understand these Important
danger zone on the Mark V when it is in the disc sander mode extends
3" on all sides of the disc, plus 3' in front and back of the disc.
The reason for the extended danger zone in the front and back of
the machine is the possibility of kickback.
your fingers, hands, and other parts of your body out of the danger
zone. Once inside the danger zone, the slight-est mistake can result
in an injury.
When you work
at the disc sander, always stand to one side of the disc, never
directly in line with the plane of rotation. Use push sticks and
other safety tools to help guide the workpieces close to the disc.
This keeps your fingers out of danger. Never reach under the table
while the sanding disc is running to tighten the locks or make adjustments.
Remember, the danger zone extends under the table, too. Turn off
the machine and let it come to a complete stop before making adjustments.
- Always wear
proper eye and ear protection, and a dust mask. If you're doing
a large amount of sanding, you should wear a respirator.
- Turn on the
Mark V, let the disc get up to speed, then feed the workpiece.
Don't turn on the power with the stock laying on the worktable
or already in contact with the disc.
- Never reach
over the disc or behind it while it's running.
on the downward motion side of the disc (Figure
17-3). The rotation helps to hold the workpiece against the
table. If you sand on the upward motion side, the disc will lift
the piece off the table and cause a kickback.
Always work on the downward motion side of the disc. Click
on image for larger view.
a 1/16" maximum clearance between the worktable and the disc.
The one exception is when you use the quill to advance the disc.
Then maintain a 1/2" maximum clearance.
- Do not sand
the end grain of 3/4" stock that is wider than 5-1/2". The rotation
of the disc may lift wider boards off the table.
- When you
use the quill feed to advance the disc, attach the quill feed
lever to the side of the power plant where you can reach it most
- Always use
the worktable; add the extension table if necessary.
- Never sand
without a table supporting the stock.
- When using
the quill feed to advance the disc, back up the stock with the
rip fence. If the stock is too long to backstop, clamp the stock
to the worktable or extension table.
Before you begin
any disc sanding operation, set the Mark V to run at the correct
speed. To do this: turn the machine on, turn the speed dial to the
correct speed and let the disc come up to speed.
speeds for disc sanding are determined by the grit you're using
and the material you're sanding. Generally, you can use faster speeds
on softer woods. Faster speeds will also give you a smoother finish.
Slower speeds reduce the risk of burning the workpiece
and are better for sanding away large amounts of stock.
To help determine
the right speed for the job, use Table 17-1. A good rule of thumb
is: The softer the material or the finer the grit, the faster you
can run the sander. However, don't run the sanding disc too fast
or the wood may heat up and burn.
17-1: Disc Sander Speed Chart
or Sharpening Metal Tools - Slow (700 RPM)
These speeds are for 60 hz operations.
End grain is
harder to sand than any other surface, but the Mark V in the disc
sander mode makes short work of this chore. You can also use the
disc sander to sand workpieces to precisely the same length.
To sand end grain, position the worktable no farther than 1/16"
away from the disc (if you're not using the quill feed) or 1/2"
(if you are using the quill feed). Adjust the table height so that
the under-side of the table just clears the dust chute and the table
is slightly above the center of the disc. When selecting the speed,
keep in mind that you want to run the sanding disc a little slower
than you would for other types of sanding because end grain will
Use the miter
gauge to align the workpiece with the disc. Check that the miter
gauge is square to the disc, and mount it in the left table slot,
closest to the disc. Position the gauge so it will guide the workpiece
against the down-ward motion side of the disc; then lock the miter
gauge in the slot.
Make a five-point
check. If you plan to feed the stock into the disc, all five locks--power
plant, carriage, table height, table tilt and quill--should be secure.
If you want to use the quill to feed the disc into the stock, the
quill lock should be loose. Stand to the right or left of the sanding
disc. Turn on the Mark V and let the disc get up to speed.
If you're feeding
the workpiece into the disc, place it against the face of the miter
gauge and carefully feed it toward the disc until it lightly contacts
the abrasive. Hold it there a few seconds, back it out, then feed
it forward again. This back-and-forth motion will keep the end grain
from heating up and burning. Repeat until the end grain is completely
When using the quill feed, move the disc in and out as shown.
Don't let the stock contact the abrasive for more than a few
seconds at a time.
If you feed
the disc into the workpiece, use the quill feed to advance the disc
until it lightly contacts the workpiece (Figure
17-4). Let it stay there a few seconds, back it off, and feed
it forward again. Once again, a back-and-forth motion helps prevent
burning. Repeat until the end grain is smooth. As you work, don't
press the workpiece and abrasive together too hard. Heavy pressure
will cause the sandpaper to load up with sawdust and
pitch. It will also increase the likelihood of burning. A light,
momentary pressure is all that's needed.
If you need to sand a number of boards to precisely the same length,
use the rip fence mounted to the worktable or the extension table
as a backstop. Position the backstop so that it will hold the end
of the workpiece about 1/4" away from the sanding disc when the
quill is completely retracted.
To sand boards to exact lengths, use the quill feed and set
the feed sop to stop the disc where you want to finish sanding.
Set the depth
control to halt the disc where you want to stop sanding. To do this
easily, use a board that you've already sanded or scrap wood that
you've cut off at the desired length (Figure
workpiece on the table, against the miter gauge and the rip fence,
so that it overhangs the table slightly. Be sure the workpiece doesn't
contact the sanding disc. Then make a five-point check. Four of
the locks--power plant, carriage, table height, table tilt--should
be secure. The quill lock should be loose. If the workpiece is long,
use a miter gauge extension for more support.
Stand to one
side or the other of the sanding disc. Squeeze the safety grip with
one hand and turn on the Mark V. Let the disc get up to running
speed; then, with the other hand, feed the disc forward slowly with
the quill until it just contacts the workpiece.
Sand one end of the board until it's smooth; then turn the
board as shown and sand the other end until the depth control
stops the sanding disc.
disc, back it off, then advance it again, lightly sanding the workpiece.
Once again, light pressure is all that's needed. Don't extend the
quill all the way at this time; just sand until the first end is
smooth. When it is smooth, turn the board and sand the other end
This time, advance the disc until the depth control stops it.
procedure as needed with the other boards you have to sand. When
finished, they will all be exactly the same length.
To remove saw
marks from the edge of a board after ripping it or to true it up
so that it's exactly the same width from one end to the other, sand
Offsetting the rip fence for edge sanding.
Mount a sanding
disc and adjust the worktable height. Position the worktable so
it is no farther than 1/16" away from the disc. Mount the rip fence
on the table, but don't lock it yet. Adjust the right-hand setscrew
in the base to offset the fence (Figure
17-7). When properly adjusted, the rip fence should be 1/16"-l/8"
closer to the disc at the front of the table than at the back.
rip fence so that the edge of the stock just touches the downward
side of the disc. Make fine adjustments with the quill feed.
When edge sanding, feed the stock slowly form the back of
the worktable to the front. Use a push stick and/or push blocks.
Turn on the
machine, set the speed dial and let the machine come up to speed.
Feed the stock slowly from the back of the work-table toward the
front (Figure 17-8).
Repeat this procedure as Model 510 118" MAX. Figure 17-7. Offsetting
the rip fence for edge sanding. needed until the board is the proper
uniform width and all saw marks have been removed from the edge.
This is the first step when sanding to an inside corner. Make
the pass to the point where the disc's rim just misses touching
Although a disc
won't sand perfectly to the inside of a right angle cut, you can
get close enough so only a slight touch-up by hand will be needed.
Make the first pass by starting at one end of the work and moving
from the edge of the disc toward its center. Hold the work flat
on the table and pass it slowly across the disc (Figure
Smooth the second
edge by following the same procedure or, if the edge is short enough,
by mov-ing the work directly forward against the disc (Figure
17-10). Work so the disc's rim will just miss touching the inside
edges of the cut. If you force the work, the rim will mar it.
The second pass can be across the disc or directly into it,
depending on the length of the work. The corner will require
a bit of hand finishing.
Miters & Bevels
When sanding angles on the Model 500 use the quill to move
the disc toward the stock.
You can sand
bevels and miters by tilting the table or adjusting the angle of
the miter gauge, just as you do when sawing bevels and miters. Use
the quill feed to move the disc toward the stock on the Model 500
When sanding angles on the Model 510, position the disc through
the table saw insert (Figure
When sanding angles on the Model 510, position the sanding
disc through the table saw insert.
Miters & Bevels
difficult to accurately measure and cut mitered or beveled boards
to precisely the same length, it's best to saw them slightly oversize;
then sand them to the desired length. Sanded miter and bevel joints
To sand a miter or bevel, use the same setup you used to saw
it: (A) miter gauge angled or (B) worktable tilted. On the
Model 510 the disc is mounted through the insert.
To smooth an
angled cut, don't change the tilt of the worktable or the angle
of the miter gauge once you finish sawing. Instead, borrow
the angles from the sawing setup. Raise the worktable and remove
the saw blade and upper saw guard. On the Model 500 remove the lower
saw guard also. On the Model 510, exchange the table saw insert
for the disc sander insert. Mount a sanding disc; then readjust
the table height and position the worktable for sanding. Clamp the
workpiece in the miter gauge (Figure
17-13), and sand it at the same angle you cut it. The rip fence
can also be used to back up the workpiece (Figure
The rip fence can also be used to back up the workpiece.
When sanding compund miters, keep the miter gauge and the
worktable tilt at the same angles used when making the saw
does not change if you are sanding a compound angle cut. Just keep
the miter gauge and the worktable tilt at the same angles used to
make the original saw cut (Figure
Use the sanding-to-width
technique when you need to sand a beveled edge (Figure
17-16). Remember that the fence is offset enough to provide
clearance for the workpiece in the area indicated by the small arrow
in the photograph.
Boards can be sanded to width using this setup. In this case
the worktable is tilted to sand a bevel. The large arrow indicates
feed direction; the small one indicates the gap needed between
the workpiece and the "rear" half of the disc.
bevels and miters, and especially if the angle is extreme, position
the worktable and power plant at the right end of the machine. Length-of-work
capacity will then be from the disc to the floor.
To sand a chamfer in the edge of a board, tilt the worktable
and proceed as you would when edge sanding. Don't take off
too much stock in one pass.
By tilting the
worktable, you can also sand a chamfer on the edge of a board.
Tilt the worktable
to the right. Offset the rip fence as you would for edge sanding
and position the rip fence so that the edge of the board to be sanded
will contact the downward motion side of the disc. Make fine adjustments
with the quill feed.
Make a five-point
check--all locks should be secure--then proceed as you would when
edge sanding (Figure
17-17). Be careful not to take off too much stock in one pass.
(A) Perfect end chamfers are sanded by using a setup as shown
and feeding the disc into the workpiece. (B) End chamfering
can also be done (Model 500 only) by tilting the worktable
and using the miter gauge stop rod and the miter gauge with
using the miter gauge and a miter gauge stop rod, or by setting
up the miter gauge and the rip fence, you can end chamfer any number
of pieces so they will be exactly alike. The workpieces shown (Figure
17-18) are small, but there is no reason why the techniques
can't be used on larger projects such as fence pickets or corner
posts for box constructions.
Curves and Circles
Use a light, sweeping motion when smoothing outside curves.
Don't hesitate at any point or the disc will sand a "flat".
To sand curves,
move the work-piece in to contact the disc and then use a sweeping
motion to maintain the work-to-disc contact throughout the pass
Feed should be light and smooth even when a great deal of material
must be removed. Several light passes are always better than a single
heavy one. The disc has a fast cutting action, so excessive pressure
can cause burn marks and will lead to premature clogging of the
Use a guide to sand curved workpieces to a uniform width.
The edge that bears against the dowel must be smooth and true.
You can guarantee that curved workpieces will be of uniform width
throughout their length if you follow the procedure demonstrated
in Figure 17-20.
The guide is
clamped in place so the distance from the dowel to the disc will
equal the width of the workpiece. The stock is then slowly passed
between the dowel and the disc. There are two important factors:
(1) The curve of the workpiece where it bears against the dowel
must always be tangent to the disc; and (2) the inside edge of the
workpiece must be smooth and parallel to the outside edge, something
you can accomplish with a drum sander. If there are bumps or hollows
in the bearing edge of the workpiece, you will not get good results.
The construction details of a guide you can make are shown in Figure
Construction details of a guide for sanding curved workpieces
to a uniform width.
A special pivot fixture that you can make to sand perfect
Circular workpieces can be sanded freehand. But you will be more
accurate, especially if you need duplicates, by using the pivot
method of guiding the workpiece. The miter gauge, locked in place
and with a pin threaded in the hole that is at the end of the bar,
can be used as the pivot. You can also make a special fixture, like
the one shown in Figure
up, place the workpiece on the fixture and posi-tion the worktable
so the edge of the workpiece will be about 1/4" away from the disc.
Advance the disc so it will start sanding the workpiece; then secure
the disc's position by using the quill lock. The workpiece is then
slowly rotated a full 360° (Figure
The workpiece is mounted on the pivot post and slowly rotated
agains the disc.
Use the same
procedure, but with the worktable tilted to the right, when you
need to bevel the edge of a circular workpiece.
The pivot guide method can also be used to round off the ends
of straight pieces.
The same arrangement
is useful when you need to round off the ends of straight pieces
Drill a pivot hole at the center of the workpiece; then proceed
to sand as if the work-piece were fully circular.
details of the pivot fixture are shown in Figure
17-25. Notice that you can make pivots that are straight posts
or are pointed.
Construction details of the pivot fixture. Notice the two
types of pivot posts; one has a point to be used when the
workpiece does not have a center hole.
pointed one can be used when the workpiece does not have a center
hole. The L-shaped lock can be used to secure the sliding bar if
you remove the table insert before putting the fixture in place.
The pivots, if threaded deeply enough, will also serve to secure
the bar in a particular position.
To pivot sand extra-large circular workpieces, mount the lathe
cup center to: (A) the rip fence of the Model 500 or (B) a
rip fence extension on the Model 510. Click on image for larger
You can pivot
sand exceptionally large circles using the following setup. For
Model 500, place the rip fence on the extension table and mount
the lathe cup center in the hole used for the mortising hold-down.
For the Model 510, drill a 5/8" dia. hole in the top of a rip fence
extension. Mount the extension to the rip fence and mount the lathe
cup center in the hole. Set the height of the extension table so
the point of the cup center will be slightly above the surface of
the worktable (Figure 17-26).
Extend the quill so the distance from the disc to the point will
equal the radius of the workpiece. Set and lock the depth control
dial at 0.
After the workpiece
is in position, advance and lock the quill (the amount of extension
will be controlled by the depth control); then slowly rotate the
workpiece until its entire circumference is sanded. Remember that
the cup center point is just a pivot guide; the workpiece must rest
solidly on the worktable.
Corners can be rounded off by sanding to a line. The bulk
of the wast should be removed with saw cuts before you begin.
One method of sanding round corners is shown in Figure
17-27. Prepare the stock by sawing off the bulk of the waste
material and then finish the shaping by using the disc sander. When
the radius of the corner isn't very large, the entire job can be
done by sanding, a procedure that is especially applicable when
you need many similar pieces. Set the miter gauge at 45° and use
the miter gauge stop rod as a backup for the workpiece. Secure the
workpiece by holding the safety grip and, with the depth control
set to limit the disc's extension, feed the disc forward to sand
to a line that is tangent to the curve (Figure
This is a setup that can be used if the corners are not too
large. First sand to a line that is tangent to the curve.
Finish rounding off by working freehand.
After all corners
have been sanded in this manner, finish the job freehand. There
will be very little material left to remove.
The ends of dowls or larger rounds can be pointed or chamfered
freehand by angling the miter gauge.
or Chamfering Rounds
Pointing or chamfering dowels or rounds can be done freehand by
setting the miter gauge to the angle you need and then using it
as a guide as you rotate the workpiece against the disc (Figure
17-29). If you want more precise results or need to shape duplicate
pieces, work as follows.
Use the miter
gauge stop rod or a long extension with a stop block to back up
the workpiece. Advance the disc to the point where it will form
the chamfer or point you need while rotating the stock against the
The pattern sanding procedure shown here is useful when many
identical pieces are needed.
sanding is useful for sanding duplicate pieces, especially if they
have an odd shape. The procedure is shown in Figure
The guide, preferably
metal, is attached to the edge of an auxiliary platform which is
clamped to the worktable so the guide will be about 1/8" from the
attached to the pattern, projects over the guide to contact the
disc. Therefore, the distance from the guide to the disc and the
thickness of the guide must be considered when shaping the pattern.
The pattern must be smaller than the actual workpiece.
is attached to the pattern by tack-nailing or using nail points
projecting from the pattern. When you rough-cut the workpieces,
try to leave the least amount of material for the disc sander to