106. Accuracy, repeatability – a case

CNC Positioning accuracy, repeatability – achieving tolerance less than the accuracy Here’s a question: A CNC lathe has a positioning accuracy of 0.010mm and repeatability of 0.002mm. Is it possible to machine a diameter with a tolerance of +/- 0.006mm on this machine...

105. Key parts of a CNC fixture

CNC The key parts of a CNC VMC/HMC fixture The construction principle of all fixtures is common. All fixtures consist of locators, clamps and supports, and a body which holds all these together. A CNC VMC fixture A locator is used to establish and...

104. Mohs scale and cutting tools

CNC Mohs scale of hardness and cutting tool materials When a cutting tool cuts a workpiece, it is basically a scratching of one material by another. The tool, which is the harder material, scratches the workpiece, which is the softer one. Scratch hardness...

103. Epoxy granite beds in CNCs

CNC Epoxy granite machine tool structures CNC machines are increasingly being made of Epoxy granite, a composite of granite aggregate and epoxy resin. Pic. source: http://us.dmgmori.com/   Pic. source https://www.adambender.info/single-post/2017/03/25/Epoxy-Granite-Machine-Frame-How-To Granite aggregate is what is used in concrete in buildings. The epoxy resin is something like good old...

102. Why Gray CI in machine tools ?

CNC Why Gray Cast Iron is preferred for making machine tool parts Vibration in machine tools causes poor part accuracy and surface finish, and leads to accelerated failure of parts like bearings. It is therefore important that a large part of the...

101. Industry 4.0 demystified

CNC Industry 4.0 - just the same old ingredients, new recipe Industry 4.0 is the term for a system that comprises these 4 things: Machines + Sensors + Data transfer over internet + Software that analyzes the data and takes decisions It is essentially this: 1. There's a...

100. Cloud computing – what is it ?

CNC What is this Cloud-shoud yaar ? We are increasingly encountering the term cloud computing in software that we use, and hearing it in relation to IOT, Industry 4.0, etc. on the shop floor. What is NOT cloud computing Scenario 1: I have a single...

99. The CNC teaching gap

CNC CNC skills: The industry-education gap The picture below shows the steps involved in machining a part on a CNC lathe or machining center. There are 12 steps, and each step is a skill to be imparted. However, the typical syllabus in India...

98. What is Adaptive control in CNC ?

CNC Adaptive Control: What is it, and how does it work ? Adaptive control is the continuous monitoring of cutting load and automatic adjustment of cutting feed rate based on the load. Pics. source: Sandvik Coromant, Fanuc During machining, the cutting load may...

97. 2D, 3D, 5-axis Milling – usage

CNC 2D, 3D and 5-axis Milling - where and how much are they used ? The vast majority of CNC machines worldwide (95 % or more) are used for 2D milling. This can be milling on vertical or horizontal machining centers. The rest of...

96. CNC Milling – 2D, 3D, 5-axis milling

CNC What is 2D, 3D and 5-axis Milling 2D milling (also called 2.5 D milling): 1. The tool axis is constant during an operation. 2. The tool moves into the material along the Z axis axis, then mills a plane in X-Y. 3. The tool...

95. Turning inserts – shapes, properties

CNC Insert shapes and their properties - Turning When we select an insert for an operation, we select it based on these characteristics: - How versatile it is in cutting different part contours - Spindle power required to cut - Vibrations during cutting, which are...

94. CNC milling – chip breaking

CNC Milling with an end mill - how exactly is the chip formed and broken ? Here's a beautiful slow motion video of an end mill cutting steel. https://youtu.be/YV80NytCSHc Video source: Taegutec You can see the cutting action clearly, including the chip formation. You can see...

93. Exact stop check in Milling

CNC Exact stop check - what is it, and why is it used ? When you program a sharp corner in the tool path, you may not get a sharp corner. In the figure the programmed tool path is A-B-C, the line...