The main gear wheel's spokes now make a smoother transition with better stress distribution at their junction with the hub; and the end thrust is taken by a hardened steel ball nestled in a deep conical hole in the crossmember of the frame. This represents quite a jump from the intermediate Type M, in which the end thrust of drilling was taken by a rotating male center (opposite that of the Type N) and the endwise adjustment was by screw. Note that the frame of the present Type L is quite similar in layout to that of the Type N. Another page makes the close comparison of the changes in frame design from Type M to L and a different page shows the changes in the frames from Type N to M.