06 step nc
TRANSCRIPT
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STEP NCTool path programming in an intelligent Step NC Manufacturing Context
Adopted and edited from a presentation made by:
Raphal LAGUIONIE - Matthieu RAUCH Jean-Yves HASCOET
Institut Recherche Communications Cybernetique Nantes (IRCCyN) France.
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Scope
Introduction & Applications
Step_NC: A new approach
Lacks of curent G-code
A new vision: Step_NC
Machining strategies in a Step_NC file
The Korean Step_NC prototype
Pattern strategies
A new method to build toolpaths
Proposition of integration in Step_NC standard
Validation of the proposition
Implementation in PosSFP (Shop Floor Programming System) Development of a Step_NC numerical chain
From the CAD model to the machined part
Conclusion
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Introduction
The STEP-NC AP238 Standard
The STEP-NC AP238 standard is the result of a ten yearinternational effort to replace the RS274D (ISO 6983) M and G codestandard with a modern associative language that connects the CADdesign data used to determine the machining requirements for anoperation with the CAM process data that solves thoserequirements.
Enabling e-Manufacturing for Mechanical PartsSTEP-NC allows manufacturing organizations to seamlessly sharemachining and measurement information between machines andover the Internet. The emerging STEP-NC technology is yieldingprocess improvements including a 15% reduction in machining
time. The automated measurement and compensation enabled bySTEP-NC promises to yield parts that meet higher accuracyrequirements for less cost. The integrated simulation andverification enabled by STEP-NC promises to guarantee that everypart will be made correctly and that production will stop whenevercuts are about to be made that do not meets design requirements.
Resources: Step Tools, Inc. http://www.steptools.com/library/stepnc/
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Working Steps & Advanctages
Working Steps
STEP-NC changes the way that manufacturing is done by defining data as"working steps": a library of specific operations that might be performed ona CNC machine tool. In other words, it breaks down every machiningoperation into the steps required to perform the operation. In the past, CNCmachine tools had to be programmed using G and M codes (from ISO 6983),which were instructions that only told the machine what moves to make,without any semantic content that referred to the part being processed.
STEP-NC will make G and M codes obsolete.
AdvantagesWith the concept of "working steps" in place, the manufacturing processbecomes streamlined. Now, a machine tool can receive a file with STEP-NCdata, "know" what it means, and proceed milling the piece without any moreinstructions. There will be no more programming the machine tool for each
individual piece. Moreover, the benefit of the standard goes further. With aset of standard "working steps" in place, all manufacturers will be able toshare information reliably and instantaneously. A STEP-NC converted CADfile that is completed on the east coast can be sent over the internet to amachine shop on the west coast and they can immediately start milling thepart.
Resources: Step Tools, Inc. http://www.steptools.com/library/stepnc/
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Applications
Step NC will enable:-
Smart Process Control
Smart Process Monitoring
Smart Manufacturing
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The current programming standard : G-code
CAM Post-processor
M216
G0 Z25
G0 X50
Y60 G1
X95 M02
G-Code
Based on principles of the 60s
Ambiguous semantics in some cases
Vendor-specific extensions Difficulty of changes on the machine tool
Impossible Feed back
Use of post-processors
As many configurations
as CAM softwares /
machine tools
more than 4500 today
Step_NC: a new approach
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Benefits of Step_NCA new vision of the numerical chain
Total integration of
CAD-CAM-CNC
Total integration of
CAD-CAM-CNC
No information
lost
No information
lost
Implementation of a
single file
Implementation of a
single file
Bidirectional
data flow
Step_NC: a new approach
No more post-processors, no G & M codes
Machine-unspecific program
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Comparison G code Step_NC
Step_NC: a new approach
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CNC in Step_NC numerical chain
Step_NC: a new approach
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Structure of a Step_NC file
Step_NC: a new approach
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Korean prototype of Step_NC numerical chain
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PosSFP :
Featurerecognition
Choice of machining
strategies attributesStep_NC file
generationMachining entities
Step_NC: a new approach
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Study situation in Step_NC development
First step :
Goal :
Interpreted
programming
Evolution with
:
Integrated
programming
Advanced
programming
Step_NC: a new approach
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First step : Contribution to standard development
Enrichment of strategies proposed in Step_NC :
Pattern strategies : GUIDE CURVE + PATTERN
Exemples of strategies built on pattern curves :
Trochodal
milling :
Plunge
milling :
Pattern strategies : a new method to build toolpaths
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Validation of this proposition of integration
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CAD
partMachining
PosSFPReading
tools
Toolpath
generation Adaptation
Step 1 :
Implementation oftrochoidal milling in :- Step_NC Standard
- PosSFP
Step 2 :
Building of readingtools and toolpaths
generators
Step 3 :
Machiningtest parts
Step_NC
Strategy
parametersToolpaths
Step_NC
File
Integration of pattern strategies in Step_NC
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Conclusion & More Benefits of Step NC
Creation of an interpreted Step NC numerical chain
First Step through advanced programming
possibility to work with Step NC on conventional means
Interest of pattern strategies
Generation simplicity
Few attributes needed to generate a complete toolpath
Easy portability
Compatibility with Step NC standard and high level programming
Enrichment of Step NC possibilities
Pattern strategies
Step NC
Conclusion
- G-code programming is no more the solution
- Bidirectional data flow
- 1 single file (no lost of data, no redundancy, etc.)
- Less correction time
- Step_NC file portability
- Total integration of CNC feed-back to design and NC planning
- Capitalization of shop floor feedbacks and experiences
- New possibilities for toolpath generation and machining strategies
- Ability ofreal-time adaptation and optimization of toolpaths and machining parameters
Advanced Step NC