Quick answer: Most drum sander problems trace back to three things – too deep a cut, the wrong feed rate, or a loose or worn part. Burning and stalling mean the cut is too deep or the feed too slow; snipe means the board isn't supported or the tension rollers are too tight; ripples and lines mean the conveyor is slipping or a bushing is worn. Work through the checks below before you order parts.
Drum sanders come in two forms. Portable drum sanders spin a sandpaper sleeve on a metal drum and are used on flooring, where they strip multiple layers of wood and finish. Stationary drum sanders thickness and smooth everything from thin strips to wide panels. Both are robust, but sooner or later you'll see chatter marks, a stalling motor or a conveyor that won't behave. Here's how to diagnose each one.
Motor problems
Motor won't start
Almost always power. Check that the cord hasn't been pulled from the wall or from the outlet near the power-feed motor, then check the fuse and the breaker – replace or reset as needed.
Motor overloads
Confirm the circuit can supply what the machine needs; move to another circuit if not. If the circuit is fine, the material is overloading the sander: slow the feed rate, and if it still trips, reduce the depth of cut or the RPM.
Drum motor or conveyor gear motor stalls
Too deep a cut. Take less per pass or slow the feed.
Conveyor motor oscillates
- Motor misaligned – loosen the housing bolts, run the motor briefly, retighten.
- Worn shaft collar or bushing – inspect and replace.
- Bent drive roller – replace.
Conveyor problems
Conveyor rollers run intermittently
Usually a loose shaft coupling. Align the shaft flats on the gear motor and drive roller, tighten the coupling set screws, and adjust belt tension.
Conveyor belt slips on the drive roller
Belt tension is wrong, or the cut is too deep. Adjust tension first, then reduce depth or feed rate.
Material slips on the conveyor belt
- Cut too deep – reduce it.
- Tension rollers set too high – lower them.
- Feed rate too fast – slow it.
- Dirty or worn conveyor belt – clean it, or replace it.
Conveyor belt tracks to one side or wobbles
- Belt needs re-tracking – adjust.
- Rollers out of alignment – re-level the machine.
- Conveyor table not flat or square – adjust.
- Belt worn – replace.
- Drive roller damaged – inspect and replace.
Drum height won't adjust smoothly
- Height control out of adjustment – check and reset.
- Worn bearings – replace.
- Dust in the height-adjustment rod threads – clean and lubricate.
Knocking noise from the drum
Worn drum bearings. If new bearings don't fix it and the machine is under warranty, call the supplier.
Problems on the wood
Snipe (gouging at the ends of the board)
- Board not supported – use roller stands on the infeed and outfeed.
- Conveyor drive or driven roller not level with the bed – adjust the height.
- Tension rollers pressing too hard – back them off.
Burning or melting the finish
- Feed rate too slow – speed it up.
- Cut too deep for the grit – lighten the cut or go coarser.
- Abrasive loaded – clean it with a belt eraser or replace it.
- Drum out of alignment – realign per the manual.
Gouging
- Loose conveyor belt – tension it.
- Cut too deep – reduce depth or RPM.
- Wood slipping – change how you feed it so it keeps contact.
- Abrasive too fine for the job – go coarser.
Lines or grooves
An inconsistent feed rate. Keep it steady from start to finish.
Ripples
Unevenly spaced ripples come from slipping – the conveyor belt on the drive roller, the board on the belt, a stalling gear motor, a loose set screw on the shaft coupler, or dry or worn conveyor bushings. Tension, tighten, lubricate or replace as appropriate. Evenly spaced ripples mean the feed is too fast, the cut too deep, or the sander is vibrating; for vibration, tighten loose parts, clean the drum, and if it persists have the drum balanced.
Burning on the abrasive paper or backing
The paper is overlapping on the drum, or the gap between wraps is too small. Re-wrap with about a 1/16" gap.
Abrasive rolls that make all of this easier
Cutting your own strips from a roll instead of buying pre-cut wraps saves real money and takes a few minutes. Our drum sander rolls come in zirconia and aluminum oxide, in widths from 2" to 6", on a cloth backing that wraps without cracking and resists loading – which alone eliminates half the problems on this page. Hook & loop versions are available for drums with a loop covering. If you need a new feed belt, we stock replacement conveyor belts for Performax, Jet, SuperMax and Grizzly.
