Troubleshooting Surface Ripples with a Drum Sander
Wise advice helps a woodworker get better results from his drum sander. September 5, 2011
Question
I have a Performax 1632 drum sander I am having trouble with. Regardless of the species, feed rate, and depth of cut I get uniformly spaced ripples in the sanded surface. I have checked for loose bolts, loose coupling shaft set screws, and the conveyer belt and cannot find the solution. Anyone have any suggestions?
Forum Responses
(Solid Wood Machining Forum)
From contributor L:
That's the nature of a drum sander. You will need to random orbit sand the ripples out. Getting a widebelt sander with a platen or a stroke sander will take care of your problem.
From the original questioner:
I am familiar with the ripple from drum sanders. This sander leaves ridges about 4" on center and more significant I wonder if it is bearings.
From contributor L:
How old is the machine?
From the original questioner:
A couple of years at most, with light use.
From contributor S:
I have a 22-44 and I can say I don’t like the feed rate and other things as well but I get a flat finish product. If your board is feeding through in a jerking motion, like the conveyor is turning but the wood stalls for a half a second this will cause ripples. You need more pressure - lower the drum to take more off at once.
Remember that these machines are not made for speed. I use 150 grit and a feed rate of two and take about a 32nd on cherry and maple doors. This allows for a lot of down pressure. On your two down pressure rollers, you want to tighten them all the way down till they don’t move and then loosen them so there is about 1/8" of play up and down. The springs in the pressure rollers are weak so this helps with the jittery feed rate and makes sure the material stays planted to the table. Basically you have to make sure the conveyor motor is working hard. I made in-feed and out-feed tables so when I run doors through I can be doing something else while there sanding.
From contributor Z:
The suggestions made by Contributor S should fix your problem. If not, check your drum to make sure that it isn't out of whack.
From the original questioner:
I will give your advice a try. My feed rate scale goes from 0 to 100 . Do you really mean two? I could have dinner and a movie by the time eight feet are sanded.
From contributor S:
Mine reads 0-10 so on your machine that might be 20 but I can tell you no matter what it’s going to be slow. If you want speed these machines are not fast. You can either do ten fast paper thin passes or one thick pass. You could use 80 grit to race it through the sander and then sand for a half hour with an orbital to get the 80 grit scratches out.
From the original questioner:
Success! Super slow feed rate, 1/32 in. cut and adjust the pressure rollers.
