Recently I saw a shaper/slotter attachment on ebay. It attached to the spindle of the mill and must have used some gearing so that the shaper spindle went up and down by use of a spiral cut into the side of the spindle on the shaper. The product was made by Chien Dai. Anyone know anything about these or a similar shaper that utilizes the spindle on the milling machine to operate the attachment? Or where to get them.