Build a lathe drum sander for $50

A wood lathe already owns the expensive parts of a thickness sander: a strong motor, a chuck, and a live center. This build adds the cheap parts — a plywood frame, a piano-hinged tilt board, and a shop-made drum — and produces a compact thickness sander for about $50 that mounts to the lathe ways in a minute and stores on a shelf when you are done.

Shop-built sanders are an old tradition. Fine Woodworking was publishing homebuilt thickness-sander plans as far back as issue #21 (1980), for the same reason this design makes sense today: the machine is mostly frame, and the frame is mostly plywood. This version comes from this site's own archives. Awilda (Tita) Wilson contributed it to Woodturning Online in the 2000s, crediting Bob Hewson of the Segmented Project Planner group for the original idea, and the original article is preserved in the Internet Archive. The dimensions below fit a Jet midi lathe — scale them to your machine and drum.

Why would a turner want one? Flattening segmented rings is the classic answer. Glued-up rings need their faces sanded dead flat and parallel before stacking, and doing that by hand is slow and inaccurate. If you turn segmented work, this pairs directly with getting your rings centered. It also thickness-sands small boards, box lids, and resawn stock that a planer would tear out.

The parts list

Everything except the hardware comes from a quarter sheet of 3/4" plywood.

A 9-inch frame width was the practical maximum on the original midi lathe. Wider frames need longer drums, and longer drums flex — the standard failure mode of every stretched shop-built sander.

Mounting to the ways

The frame must sit exactly square to the lathe axis, and the original build solved this simply: a piece of 3/4" plywood screwed to the underside of the base drops between the ways and registers the frame at 90 degrees. A 3/8" bolt passes between the ways into a tapped steel plate — the same width as the hold-down washer your lathe stand uses — and clamps everything down. A heavy washer and nut work if you have no tap.

Making the drum

Cut discs of 3/4" or 1" MDF with a hole saw, glue them into a cylinder over a threaded rod, then mount the assembly between chuck and live center and true it with a gouge. Because the drum is trued in place on the machine that will spin it, concentricity comes free: the original unit measured less than 0.001" of run-out. A pen mandrel can substitute for the threaded rod on short drums, and PVC pipe filled with plaster of Paris around the rod makes a heavier, quieter drum.

The glued-disc drum has history behind it. As T.R. Warbey notes in Fine Woodworking #21 (1980), his dulcimer-shop thickness sander used the same construction — plywood discs glued on a steel shaft — held stock down to 0.040", and cost under $20 in 1980 parts. Two independent builders arriving at the same drum, decades apart, is a good sign the pattern is sound.

Mind the surface speed. A 2.5" drum at a midi lathe's 1,800 RPM moves its abrasive at about 1,180 feet per minute, and every extra inch of drum diameter adds roughly 470 feet per minute at that speed. That is quick enough to burn resinous woods on a stalled feed, which is one more reason the light-pass rule matters.

Surface the finished drum by laying sandpaper on the tilt board and pulling it back and forth under the spinning drum until the face is even. For grit, the builder of the shop stroke sander in Fine Woodworking #3 (1976) settled on 100 grit as best for most work, and that matches my experience on a lathe drum: I recommend 80 grit for hogging segmented rings flat and 120 grit for the final thickness passes. Coarser than 80 leaves scratches the glue line shows forever; finer than 120 loads too fast to be worth it.

Attach the working abrasive with spray adhesive — hook-and-loop works but costs more and is fiddly to align on a shop-made drum. A drum that cuts slowly is usually loaded paper, not a dull abrasive — unlike your gouges, which do need regular sharpening.

The height adjustment

Thickness control comes from tilting the board, not raising the drum. The tilt board rides a piano hinge at one end; at the other, a 1/4"-20 threaded rod through a swiveling nut-plate raises and lowers it. The swivel matters: as the board tilts, the rod angle changes slightly, and a rigidly mounted rod would bind. The original build welded two 3/8" nuts to a small plate with a short bolt between them, letting the whole assembly pivot.

Quarter-20 thread gives fine control — one eighth of a turn is about 0.003" of cut, which is the right order of bite for a sander. To keep the piano hinge from wandering during installation, clamp the board and hinge block together and drill the screw holes with a self-centering hinge bit.

Hold-downs and the feed tray

The work rides through on a 1/4" MDF feed tray with sandpaper glued on top for grip. Thin MDF bows slightly, so the build adds spring-loaded hold-down rollers: 1/4" rod running through 3/8" nuts, wrapped with coil springs, carrying small wheels. They do two jobs — pressing the tray flat against the tilt board, and stopping the tray from tipping up as the trailing end of a board or ring clears the drum. Without them, the work lifts into the drum at the end of the pass and gets sniped.

The dust hood is not optional

Sanding throws far more dust than cutting, and this machine concentrates it. The original hood used 5/16" plywood sides with an acrylic front panel so you can watch the cut, hinged at the rear for paper changes, with about 1" of clearance over the drum — the spacing that collected dust most efficiently in use.

There is a second reason beyond your lungs: dust that escapes drifts under the feed tray and physically changes the thickness setting mid-batch. If your rings come out tapered, check for packed dust before you blame the machine. The same discipline applies here as in any drying or finishing setup — control the environment or it controls the result, which is the whole argument behind a shop-built drying kiln as well.

Using it: the five-step pass

1. Set the bite. Lower the drum until it barely kisses the work surface, then back off and advance one eighth of a turn. I recommend treating 0.003" as the maximum cut per pass, not the starting point.
2. Feed steadily from the tailstock side. Push blocks only. Pausing mid-pass burnishes a low spot into the work.
3. Check thickness at both ends of the board or ring. Tapered output means packed dust under the feed tray, not a machine fault.
4. Flip and repeat for parallel faces. For segmented rings, sand one face flat first, then flip and sand to final thickness — parallel faces are exactly what a clean glue-up needs.
5. Clean the paper when it loads. A crepe cleaning stick run against the spinning drum recovers most of the abrasive life.

Total cost in the original build: about $44 in 2008 parts, call it $50 to $70 today depending on what hardware is already in your drawer. The lathe does everything else.