Gang rip trouble
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Q: We have a gang rip saw that we have trouble with. When the lumber is about halfway through, the piece travels away from the fence. The infeed has rollers that are at an angle so that the lumber is pushed against the fence. That seems to work well for the beginning of the pieces, but then it moves away from the fence. When we increase the feed roll pressure it seems like it might get worse. Any ideas?

A: I will bet that you have an outfeed roller system that is actually moving faster than the infeed rolls. With the lumber accelerating in speed as it progresses through the saw, this will actually counteract the angled infeed rollers and pull the lumber away from the fence. (If you can imagine that with slowly fed lumber, the rolls will push the lumber tightly against the fence, but if the lumber goes faster than the rolls, it will be like running the rolls backwards.) Can you move the higher speed outfeed system away from the saw a few more feet?  Or maybe you can slow it down a bit.

Special notes: This difference in speed can also cause problems with routers and other similar equipment. There is the same problem with straight rollers with a spiral ridge.

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About the author
Gene Wengert

Gene Wengert, “The Wood Doctor” has been training people in efficient use of wood for 45 years. He is extension specialist emeritus at the University of Wisconsin-Madison.