Lathe Operated Drum Sander

Our thanks to Awilda (Tita) Wilson for creating and offering
this project to fellow woodworkers.
Tita would also
like to thank Bob Hewson of the Yahoo Group's Segmented Project
Planner Group for sharing his idea for a lathe operated drum
sander.
We built the pictured drum sander for about $44 in parts. The unit is
operated by the lathe motor, can be removed easily and is quite compact.
The specifications we give are for a sanding unit to fit a Jet midi lathe.
You will have to modify the dimensions to fit your particular lathe and
the diameter and length of your drum.
The base plate, tilt board, and side plates are all made
from ¾ plywood—Home
Depot sells ¼ sheets at a reasonable price, and one quarter sheet
was enough for our unit. A 9 inch width for the sander frame was about
max for our lathe. The drum sander is secured to the lathe ways using
an appropriate length 3/8 bolt and large top washer. We carefully measured
and mounted a piece of ¾ inch plywood on the bottom of the support
board—that piece falls between the ways, and keeps the frame
at exactly 90 degrees to the lathe ways. The tie-down bolt is fed
between the ways and into a piece of 3/8 thick metal tapped for the
bolt (A heavy washer and appropriate nut will also work). The metal
is just as wide as the hold down washer that came with the lathe
stocks (see pictures).
The drum cylinder can be made by cutting rounds (using
a hole saw of appropriate diameter, or the Ringmaster) out of ¾ or 1” thick
MDF and gluing them together to form a cylinder. A threaded
rod is inserted through the center although a pen mandrel can be used
(this limits the drum length), then the lathe is used to true the cylinder
and allows custom cutting of needed diameter and length.

We were fortunate in that we had a piece of round, very
hard solid plastic cylinder 2 ½ inches in diameter available
(a dump find!), so we drilled and tapped one end for a piece of threaded
bolt stock on the chuck end, and merely dimpled the other end for the
live center.
(Editor note: I've seen a similar setup using PVC pipe
filled with plaster of Paris and the threaded rod)
Once the unit is fastened down, the drum can be inserted into the lathe
chuck and live center. With a piece of sandpaper on the tilt board, sand
the drum smooth and even by pulling the sandpaper back and forth under
the drum. The unit is extremely stable, and run-out on the drum is less
than 1/1000 inch.

As for “Note A” on the attached drawing of the pivot assembly
of the height adjustment unit, we welded two 3/8 nuts to a small metal
plate, after threading a short piece of 3/8 bolt between the two. We
then welded a piece of ¼ inch rod for use as the height adjusting
rod to the aforementioned bolt at right angles, fastening the
plate to the tip board. This allows the height adjusting rod to swivel
the slight amount needed as the tilt board is raised and lowered.
Quarter-20 rod for the height adjustment gives a great adjustment
potential. Turning the knob 1/8th turn is a gradual enough adjustment
to remove small amounts of material at a time. The knob came from
OSH. The saddle we placed below the base keeps the adjustment knob
out of the way of the tilt board.
There are piano hinges attaching the tilt board to the
base and one attaching the dust collection cover to the side panels.
To make sure that the piano hinge we used for the tilt board was perfectly
aligned, we clamped the tilt board and the hinge block tightly together
then used a self-centering-hinge-screw drill bit to drill starter holes—this
insured that the hinge didn’t wander while screwing it down.
The dust collector hood appears to be absolutely necessary,
as the sanding operation generates a lot of dust (obviously), and without
it, dust tends to get under the feed tray and change height settings.
The collector gets most of the dust, and the 1” clearance to
the top of the drum seems the most efficient. The dust collector was
made from 5/16 ply we had on hand, with a Lucite front panel to facilitate
viewing the drum and material while at the same time providing a measure
of safety. The dust hood rear panel is permanently attached to the
rear of the upright side panels, and the top and front of the collector
is hinged in the rear to facilitate changing the roller paper. We used
spray adhesive to attach the sandpaper to the drum and feed tray. Hook
and loop attachment can also be used but was more expensive and difficult
to work with.
CAUTION!! THE LATHE TURNS SO THAT MATERIAL IS PULLED
AWAY FROM YOU. THIS COULD INCLUDE INJURING YOUR FINGERS—SO PAY
ATTENTION. (SEE FEED NOTES FURTHER ON IN THIS SHEET)

The hold down rollers serve a dual purpose: First to
hold the feed tray down firmly against the tilt board—the feed tray is ¼ inch
MDF and it tends to bow very slightly (1/4” ply tended to bow and
twist even more)—the rollers handle this very well; secondly
the rollers keep the feed tray from either raising or dropping as
the sanded board or ring was clearing the sanding drum. (Without
the hold down rollers the back of the tray would tend to tip up causing
the material to be sniped by the drum and damaged.)
We made the spring loaded hold downs using ¼ inch rod running
through 3/8 nuts (a fine fit) with a coil spring around (and anchored
to) the rod to load the rollers. The “wheels” are small bearings
that come with a lip on one side. They came from OSH, and are tack welded
onto a shaft, which in turn is welded to a small plate that slides up
and down against the main bracket—this small plate keeps the
bearings aligned properly so they do not wander off the edge of the
feed board.
We used a 1” wide strip of the ¼ inch MDF
glued to the rear of the feed board as a stop, and also glued 100 grit
sandpaper onto the top of the feed tray. This is fine for keeping the
work piece in position while feeding through the drum.

Feed Note: PLAN ON FEEDING MATERIAL ONLY FROM THE REAR,
AND TAKE LIGHT CUTS. FEEDING MATERIAL FROM THE FRONT WILL CAUSE
LOSS OF CONTROL, AND IS DANGEROUS!!!
Design Documents:

