A spindle usually possesses at least two bearings or necks, which are intended to constitute friction parts on which the spindle will rotate. The necks of any such spindle require to be in line with each other; or, their axes require to be in line with each other, in order to secure a proper bearing upon the pillow-block brasses, or upon whatever other friction surfaces may be provided. A simply formed spindle is shown by Fig. 954, which is without bearing collars or flanges, and therefore will allow a wheel, lever, or other object to fit at any place along the spindle's length. Fig. 955 represents a spindle with flanged bearings; this is a light and elegant form suitable for a spindle that does not require any wheel or other article to be slid along and fit at the mid-part.

An easy and accurate method of turning a spindle that may not be more than about an inch thick consists in performing the entire turning while the spindle remains in one position in the lathe. For this purpose a piece of metal is provided which is a few inches longer than the intended spindle; and after it is centred it is put on to the lathe-pivots and gripped by fixing a carrier to the superfluous few inches near the lathe-chuck. The piece can now be rotated and the entire spindle accurately produced in its required length and several diameters without shifting the carrier by which it is rotated. Therefore any portion of the spindle which is truly turned circular will be made concentric with any other portion which is truly turned; so that all the necks it may have will be exactly true with each other, and true with the other parts of the spindle that are made to fit the lever-bosses, wheels, or other articles to be connected. A spindle produced in this manner is not cut from the extra piece at one end, until the whole of the turning and fitting is quite finished; so that it is necessary to carefully measure it, and ascertain what are the exact dimensions intended; also to thoroughly fit every part, previous to cutting off the end, in order to avoid the liability of having to centre it for some further turning that was not foreseen. When the end is to be removed, a deep groove is made around at the proper place, to allow of an easy breakage. A groove of this sort is seen in the spindle shown by Fig. 956.

It may be also stated that if a spindle is specially required to have a centre recess at each

2 s2 end, it may be first cut to the length and centred at each end; consequently such a piece will require reversing end for end in the lathe, and the carrier or gripper must be fixed to both ends.