Especially when using high magnification it might be very hard to find proper focus. Try to adjust the focus and the shaking will prevent determining if the focus got better at least for a while. This can be avoided by replacing the mount with a more robust one (can be very expensive) or mounting this simple focus motor which is compatible with the Sky-Watcher Crayford focusers but can be mounted on older models as well. The speed is adjustable between 2.5 and 7.5 rps.
