Reducing Lathe Vibration, Part 1 - Improper Technique
Most of us, especially those with smaller lathes, have experienced the frustrations caused by vibrations when turning with our wood lathes. There are a wide variety of factors that can cause vibration...here are some tips for reducing the problem. In this first part of our two part series about lathe vibration, we're going to cover problems that are caused by the turner...not the lathe itself.
Improper tool sharpening -
Dull and improperly sharpened tools require more force to be placed on the tool to cut the wood. Using additional force against the wood can cause the piece to vibrate. These vibrations show up as "chatter" marks on the wood's surface. Keep tools properly sharpened at all times!
Excessive force used in cutting -
As a turner, you must learn to let the tool do the cutting for you. While it may be tempting to push one's tool into the wood as quickly as possible, this is not the proper way to turn. As with improperly sharpened tools, the additional force that is placed on a piece will cause vibrations which lead to chatter marks. Using a light touch with enough pressure to keep the tool moving in the proper direction will greatly reduce chatter marks caused by the vibrations that are no longer being created.
Improper cutting direction -
A few months ago we covered proper cutting direction in our newsletter (see our archive for these back issues). Cutting wood in a manner that causes the fibers of the wood to be torn, rather than cut, can cause issues with vibration. As wood fibers are torn away from one another, the wood tends to vibrate slightly, producing a slightly uneven surface. In addition to this, the torn wood fibers create a rough, fuzzy looking surface. This rough surface will cause additional vibrations as well, as the tool will lightly bounce across the rough surface on occasion. If you aren't confident with how to properly cut your wood, I highly suggest looking over our tutorials mentioned above.
Improper mounting of turning stock -
While this may seem self-explanatory, we wanted to touch on two important issues concerning proper mounting. For side grain projects, such as bowls and platters, keeping things as well centered when mounting will, of course, reduce vibration. For spindle projects, proper centering is also important, but the amount of force placed on the wood between the headstock and tailstock also come into play. This is especially noticeable in longer and/or thinner projects. Excessive force coming in from the ends of the wood can actually cause the wood to flex along its length. Use just enough force to keep your wood in place, but not enough to cause the wood to flex.
In next month's issue, we'll explain what problems can be caused by the lathe, and cover the remedies for each of these situations.