重 型、矿山及冶金等单件小批机械制造和修配厂 ,工件进入加工前要进行钳工划线工序 ,用普通钳工圆规划线的精度最高能达到0.2mm ,划线质量差、效率低 ,尤其是划不同台阶平面上的圆或弧是很难实现的。如果用废旧卡尺改制成钳工划线圆规(图1) ,结构简单、使用灵巧 ,可以划不同台 Heavy, mining and metallurgy and other small pieces of single batch of machinery manufacturing and repair shop, the workpiece before entering the processing to carry out fitter scribing process, using ordinary fitter circular planning accuracy of up to 0.2mm, marking quality is poor, low efficiency, especially It is difficult to draw a circle or an arc on a different level. If the use of scrap calipers converted into fitter crossed the compasses (Figure 1), the structure is simple, smart, you can draw different sets