Re-engineering of current products to ease assembly and integrate Design for Manufacturing and Assembly within the design process A Knowledge Transfer Partnership between the University of Plymouth And Rittal – CSM Limited Rajesh Radhakrishnan

Company Profile Rittal CSM is a part of Friedhelm Loh Group Rittal International is the world’s largest manufacturer of data communication and industrial enclosures Rittal CSM celebrating 25 th year in Plymouth Products are classified into OEM and Non OEM

Business Driving factors Rittal has started concentrating on Cost and Time Reduction. High Quality Quicker to Market Low Cost DFMA Lean Design Practise

Introduction to my KTP project KTP Project Redesign the current products considering DFMA Implement DFMA within the design process Reduce the Assembly Time Cost Saving Designers Exposed to DFMA Cost Saving in Future Projects Improved Manufacturability and Assembly

DFMA Design Proposals Snap fit Lock Rod Block Present Component New design Cost Saving / Rack £0.43 Cost Saving/ Year £25,800 Side Panel Fixing Depth bracketUniversal weld bracket Cost Saving / Rack £ 1.28 Annual Cost saving £ 76,800 Tail Bar Cost Saving / Rack £ Annual Cost Saving £ 34,500

DFMA Design Proposals Simplified new of rear door assembly New castor bracket with reduced fixings DFMA design top canopy with tool-less fixings Tool-less snap fit logo batch New castor wheels Cost Saving / Rack £ Annual Cost Saving £ 104,640

Implementing DFMA within the Design practise Detail study was done on various DFMA techniques such as Boothroyd Dewhurst, Lucas and Lean Design. Analysed the work culture of the design department. Formulated a DFMA tool All the designers were trained on the new tool DFMA was integrated to the RFEA (Request for Engineering Assistance) system on 27/07/09

Designing or Re – Designing of component Design and Development Engineer – R.R Part reduction for Simplified Design 1.Understanding the application. 2.Evaluate each part, a. Can be eliminated? b. Combined with others? c. The function can be performed in other ways? Questions for Part reduction Does the part have a relative motion with other parts? Does the part need to be of a different material? Is the part required for assembly or access? Standardisation of parts 1.Standardisation by using common parts, processes and materials across all models and other product lines. 2.Minimise unique or customised components. 3.Use PDM, CSM, material catalogs and approved part lists for standardisation of components. PDM - Product Data Management systems CSM- Component Supplier Management systems Consideration of Fasteners and Joints 1.Use standardised fasteners and minimise variety. 2.Use integral attachments like snap fit, Interference fit, integral hinges, self jigging subcomponents, plastic part locking etc. 3.Consideration of tool less and plastic fasteners. 4.Consider the material, product functional requirements, assembly and service before selecting the fastening technique. Design for part handling and self securing 1.Add features to parts which aid in self securing. 2.Design end to end and rotationally symmetrical parts. 3.Design parts that are easy to grab and fix. 4.Avoid sharp edges, excess flexibility, heavy parts etc. Design for ease of assembly 1.Avoid or minimise the need for part orientation during assembly. 2.Avoid the need for measuring gauges. 3.Ensure accessibility, visibility and never bury the important components. 4.Provide chamfers and tapers. 5.Take advantage of aid of gravitational forces. 6. Avoid using temporary fasteners Design for Fabrication and Processes capability 1.Eliminate unnecessary part features. 2.Avoid unnecessarily tight tolerances. 3.Design components for improved reliability by controlling the noise factors (considered in the concept phase) 4.Design components with simple shapes and avoid machining. 5.Choose cost effective fabrication techniques eg: castings, stamping etc. 6. Use features with standard dimensions in the design. 7.Avoid undercuts, thin wall or webs, counters, deep pockets etc. Noise Factors - Factors beyond the designer’s control but affecting the design eg: transportation, improper loading and unloading etc. Component Design for error free Assembly 1.Design components with verifiability eg: go/no go, stopping points, using notches, asymmetrical holes, stops etc. 2.Avoid the need for assembly to make decisions and manual adjustments. 3.Control the features in a product which are prone to error. 4.Use colour codes for the parts which look alike but have a different application. 5.Provide inexpensive inspection at the end each process.

Integration of DFMA in RFEA When a design document is updated by a designer RFEA prompts for a DFMA check When DFMA is not appropriate, the reason is documented

Integration of DFMA in RFEA When DFMA is performed DFMA Design guidelines Click the drop down box in the DFMA design principles and select the appropriate design guidelines and type in the description of the design change

Major highlights of the system Design Documents cannot be uploaded without considering a DFMA check. Minimum of 4 DFMA design principles have to be considered. DFMA design checks are automatically documented for future reference. DFMA status can be viewed in the RFEA table with the designer’s updates ( can be used for DFMA performance review )

Benefits form the KTP Project Company Potential cost savings based on DFMA identified Tool less fastener selection library was formulated Reduced assembly and manufacturing complexity Product simplification Improved product quality and reliability Increased manual assembly efficiency Reduced assembly costs University Presentation given MSc Mechanical Engineering students Writing a case study on the implementation of a lean design tool DFMA design tool can be used by students Associate Real time design and manufacturing experience Good exposure to DFMA and Lean product design Gained good knowledge in tool less fastening system