My 18 inch bandsaw with woodmaster CT, at a really high tension can run so smoothly that it would pass the penny test, however sometimes while running it will suddenly become shaky and shake like crazy, and then several more minutes of runtime (which really depends) the shaking will go away. What do you think is happening? I checked everything and it seems to be in order, however I have not checked if the wheels are coplanar because I don't have a way of doing that.