CNC Machines – clearing some misconceptions

Types of CNC machining

Sheet metal cutting, forming Turret punch press Laser Water jet Video

Turning Video

Die - 3D milling Video

Aerospace - 5 axes milling Video

Production - 2D milling Video

India machine tools – 2011 stats India is 7 th largest consumer of machine tools in the world. 12 th largest producer 4 th largest importer Growth 31 % growth in consumtion 68 % growth in imports Types of machines 80 % of machines are CNC, 20 % non-CNC 75 % is metal cutting, 25 % metal forming

Some common misconceptions

Most industries do 3D, 5-axes machining. A few low tech industries do 2D machining. Misconception 1

Which of these parts do you see most often on shop floors ? What type of machining do you mainly see in these firms ?

Production machining accounts for 90 % of CNC milling. Die milling / 5-axes milling for 10 %.

3D, 5-axes machining is 'high tech'. 2D machining is 'low tech'. Misconception 2

2D3D Cycle time reduction - importanceHighLow Shop documents - importanceHighLow Process - complexityHighLow Tool selection - complexityHighLow Part geometry - complexityLowHigh Cutting parameters selection - complexityHighLow Nothing is 'high tech' or 'low tech'. Each type of machining has its own complexity.

CAM software designed for 3D / 5-axes machining can also program for 2D machining. Misconception 3

CAM software for production machining Must support wide variety of machining operations Must support wide variety of tools Must have features to reduce cycle time Must have features to check and optimize spindle power usage Must generate shop documents automatically

CAM software requirement for each application is different. Same software cannot do both. CAM software for 3D/5-axes machining Must have 3D CAD Must be able to machine complex surfaces

Programming is the main task in CNC machining. Misconception 4

Programming is NOT the main task. Programming is just one of the steps.

Misconception : Most industries do programming by CAM software. Only a few small industries program manually. Fact : Most industries program manually. Misconception 5

Skills required in industry

The gap – institute to industry Main cause of poor productivity on shop floors is lack of knowledge of tooling, cutting parameters selection. Fact : 95 % of experienced CNC personnel on shop floors do not know the full form of the commonly used word 'carbide'. Institutes concentrate on teaching programming, students think this is all that is required. Fresh engineers are as a result useless in industry, take 6-12 months to learn required skills and be useful.

Skills required in industry Machine construction Machining operations Tooling Cutting parameters selection Manual programming Programming using CAM software (optional)