8/2/2019 Fast Movers - Prezentacija

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Good day ladies and gentleman, my name is Sven Vučić and in the next ten

minutes I'm going to talk about a new technology in machine tooling, called

parallel kinematics. First of all, I would like to point out that I would prefer if the

questions you have about the topic of the presentation to be asked in the end. So

let's begin. I've divided my talk into four parts.. In the first part I'l give you an

introduction to PK and to why it is so important. Then in the second part you'll belistening about the main advantages and disadvantages in parallel kinematics.

Finally , third part will be about the development in CNC machines. During my

presentation, I'll have some powerpoint slides to assist me. So that concludes the

introduction.

Now let's move to he first part of my talk, which is about importance of PK in the

world industry. As you all know, growing competition from the East has lead the

engineering sector in the UK and the rest of the Europe to invest in automation and

the latest machine tooling technology to retain an effective manufaturing base. So

they are investing in flexible manufacturing systems with „greener“ production andthe ability to absorb new technologies quickly. Parallel kinematics is a technology

that has many potential and it combines rotary motion with simple linear

movements.

So now we come to the second part which is about the advantages and

disadvantages of PK. The first advantage is that it offers fast overall speeds, and

because of the forces that are either in compression or are tensile, it is possible to

manufacture extremely stiff but light structures. They combine processes to reduce

set-up times and floor space and can incorporate lasers, grinding wheels and EDM

die sinking. All this has an effect for the end user, which reduces capital outlay in

the purchase of one machine rather than several tooling arrangements and

fixtures. It also eliminates component transfer problems between machines and

reduces setting and component inspection. These machines are able to be

configured to accommodate one or more machining processes without the need

for separately-designed and manufactured units. Despite the promise of the

technology, problems arise due the nature of the motion. On the other hand the

disadvantages occure because parallel kinematics motion in a given direction

involves the simultaneous adjustment of several struts. Stability could also be a

problem since each strut is critical for the stable motion of the machine. If we one

out, entire machine becomes potentially unstable. These kinematic

transformations must be carried out at intervals of just two milliseconds to achievethe required smoothness of translation and acceleration. Doing this is a major

challenge for the computer controler, which needs to calibrate and compensate

errors in real-time. That' all I want to say for now on the advantages and the

disadvantages.

Let's move to the next part which is about the development of CNC machines. In

the past, CNC was responsible for slow axis positioning and basic tool

management. As machines center have evolved, axis positioning requirements

have drastically increased while tool management have become drastically

complex, demanding far greater processing power to handle them. Machine tooldevelopers are using parallel processing technology that allows them to use tow or

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more microprocesssors to work simultaneously. But there is a conflict between

CAM developers and the controller manufacturers when it comes to controlling the

dynamics and ease of programming toolpaths. What is important here is that one

beautifully thought out user interface is worthless without the control software that

drives the machine tool's kinematic and conversely, new kinematic technologies

are worthless if they are to difficult to implement in a part program. This brings usto the end of my talk.

  To sum up, CNC machining is going forward, and the future is in fast,

multifunctional and multi-threaded units that can do one or more machining

processes.

 Thanks you for listening, and if you have any questions, you can ask them now.

Nobody ? Thank you...