由于不等齿距铰刀所有相对齿刃间的尺寸都不通过圆心。因此很难正确测出铰刀的实际直径及其切削部份、校准部份、柄部对公共轴心线的径向跳动量。采用相对测量法可解决这一问题。自制一根长顶尖(见图),在外圆磨床尾架尖的伸出部份加工成与各种规格铰刀直径大小相等的短圆柱体,用杠杆千分表测出顶出 Due to unequal pitch reamer all the relative size between the teeth do not pass through the center of the circle. Therefore, it is difficult to accurately measure the actual diameter of the reamer and its cutting part, the calibration part of the handle on the common axis of the radial runout. The relative measurement method can solve this problem. Home made a long top (see photo), in the outer part of the tip of the cylindrical grinder tail machined into a variety of reamer diameter equal to the size of the short cylinder, with a lever dial indicator to measure the top