The resulting machining marks are, therefore, a helix having a very small pitch, which is equal to the feed. Consequently, the machined surface is always cylindrical.
Programming by the plane curve unwrapped from the helix curve and cutting layer by layer, we created the variable pitch screw on the 3.5 axis NC milling.
文章基于3.5轴数控铣床，利用螺旋线展开的平面曲线编程，分层切削，加工出变螺距螺纹；
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Because pitch deviation measuring technology is very mature, the main research objective of this thesis is laid on the checkout of profile deviation and helix deviation.