Nothing beats a spindle hand crank for sneaking a thread up to a shoulder or locking the spindle while removing a stubborn chuck.
The aluminum cylinder is slip fit in the spindle bore. The cone nut, pulled in by the bolt, expands it like an expansion collet, and makes it grab the inside of the spindle. The crank arm is screwed to the expanding cylinder and has a rotating handle. It's especially long for lots of "command authority" torque.
and here's what it looks like all put together.
After these pictures were taken, an anti-rotation pin was added to the conical nut. Said pin rides in one of the expansion slots and prevents the cone-nut from turning as the bolt is torqued to expand the collet.