Belt sander problems

Q: Nice site, very informative. I run a small hardwood floor company out of North Carolina in the U.S. I am recently on my own but have been in the business for 15 years. I have purchased a ****** belt sander which runs great but severely digs out the soft grain in the wood, especially red oak, resulting in a rippling effect across the whole floor. Cutting on an angle has no effect and the waves get worse with each successive pass.

I have had the machine serviced several times and they can find nothing wrong, also replaced belts, bearings, roller arm, etc.The Waves are not really visible on bare wood but come out when finish or stain is applied and under low angled lighting. I have been able to lesson the problem significantly by using a buffer with a hard plate , followed by screening. This process produces good results but the hard plating ads significant time to the job. any suggestions on this problem would be greatly appreciated as I am some what fanatical about doing a high quality job and although no one else seems to notice these imperfections, I do and it`s driving me up a wall…

A: Hey, I have the same machine and believe me, I do understand how you feel. I recently took mine in because on certain jobs I was noticing that the edges of the drum were cutting into the floor and leaving grooves. And as you say, you may not notice such things until you start applying the finish. With every coat the problem looks worse. You are getting chatter marks and waves. They have this spring you can pull up on a control rod. This is for easing off the pressure on the drum. They have told me not to pull this up too far or it will cause chatter.

I have the luxury of being ten minutes from the factory where this machine is made, and in fact know the owner and his family. When they checked my drum, they placed it on a level aluminum surface and ran it without a belt. They gently lowered it onto the plate and discovered that it was cutting on the edges before the center of the drum touched. He then set it over an abrasive and gently ground the drum until the edges were the same as the middle. In effect the drum was now flat. Maybe doing the same check could reveal a problem with the drum.

I will give you their number, so you can call them directly. Ask for *******
(the owners son) or ********* (a mechanic in the plant) or **********, the
owner. Ask for James first.

Toll free: xxx-xxx-xxxx or xxx-xxx-xxxx. They make the machine. They ought
to be able to help you.

Make sure your wheels are clean, and blow out the guide roller and other belt mechanisms after or before every job.

Please let me know what you find out.