Presentation on theme: "Are your CNC machines making money, or just chips ?"— Presentation transcript:
Are your CNC machines making money, or just chips ?
Making money, or just chips ? Can you spot the difference ?
Making money, or just chips ? An adult elephant costs about Rs.3000 per day for its food and medical expenses. Therefore, you would make it work to its fullest power.
Making money, or just chips ? Your typical CNC lathe costs twice what an elephant costs, for space, power, tooling and manpower. Fact : Most people use their CNC machines like this. Why? Because their programmers are obsessed about the part program, not the productivity. Because programmers think if the part is dimensionally OK, then their job is done !
Reduced cycle times = Money 1. Cutting parameters must be optimal. 2. Tool path must not have wasteful motions. 3. Spindle power must be used to the maximum. 4. Calculate cycle time accurately. 5. Analyze cycle time operation-wise. 5 things you must do, but you never do: Why ?
1. Cutting parameters Improper cutting parameters - one of the biggest causes of poor productivity on shop floor. Caused by: - Lack of knowledge of FS selection - Unnecessarily cautious approach - Use unscientific thumb rules Most programmers do not have knowledge to select correct FS, so they dont do it.
2. Tool path Tool path is often longer than necessary during manual programming, particularly when the blank is a casting or forging. You need to do extensive trigonometric calculations to eliminate wasteful cutting and rapid motions. This can take be very laborious and time-consuming, so you don't do it.
3. Spindle power If you are only using 50 % of the power, your cycle time is 200 % higher than what it can be. To achieve maximum power usage - check power while cutting on the machine, change FS, check again, etc. This is laborious and time-consuming, so you don't do it. =
4. Cycle time – accurate calculation To calculate cycle time accurately you need to consider the tool travel distances, effect of CSS, axes acceleration / deceleration, spindle acceleration / deceleration, etc. It is impossible to do this manually, so you don't do it.
5. ABC analysis of operation-wise times Analyze operation-wise machining times. Identify operations that have the maximum scope for time reduction, reduce their cycle time by changing FS. Needs detailed breakup of machining times. It is impossible to do this manually, so you don't do it.
Do multiple iterations You need to do these 5 things cyclically, repeatedly, and arrive at the optimal cycle time. You typically do not have tools to do them, and getting a working CNC program out is itself a big headache. So you do not do this.
Post mortem check - useless If you are like most users, you cannot do the 5-point cycle before starting machining, since you do not have the right tool to help you. So you occasionally check the cycle time AFTER starting machining. Too late to bother about productivity.
Make money, and not chips 1. Think of your machine spindle as an elephant's trunk. To get best return on your investment, use it to the maximum. 2. Be obsessed about the cycle time, NOT about the program. 3. The program should be the last thing you should think of. 4. CAPSturn enables you to do the 5-point cycle, that can generate CNC programs automatically, 'untouched by human hand'. Summary