Initial Consultation
Overview
In the initial consultation, we explore your project and learn about the problem you would like solved, or the existing concept you would like to build on. The more aspects of a project that can be defined early on, the more the designer has to work with, in order to iterate toward working solutions.
This stage defines aspects of the project like schedule, budget, scope of work, critical path milestones, risk management, disciplines required, documentation, business relationship, and prioritizing which design goals are required, and which are preferred, and which are excluded.
After the consultation, a signed contract is required to move forward into Concept Development.
An example of scope definition could be to build a workbench of a specific length and width, a capacity of 1,000 lbs; raise, lower and tilt; manual or powered; with a cost and time estimate. If the customer is sourcing the tabletop separately, then the project would focus solely on building the articulating mechanisms, and the table top would be "out of scope".
Concept Development
Overview
Following consultation, this stage creates one or more working concepts through brainstorming and rough calculations to explore which ideas are feasible before moving into the more detailed process of mechanical design.
Workbench Example: After the Consultation phase, this stage explores alternative design approaches with sketches of tables featuring several geometries, materials, systems or mechanisms, to accomplish the same raising and tilting features in different ways.
Concept Proposals
Overview
Ideas start to take shape in this phase, concluding with a winning design. In this first design review, working concepts are presented from the Development phase, comparing the compromises of the different design approaches. The customer now has feasible solutions to compare, prompting more detailed questions about materials, cost, schedule, and a refinement of the solutions. This phase may iterate a few times until a decision is made on which version moves into the Design Phase.
Workbench Example: The group would compare the tradeoffs between three designs. The first version could use two worm drive gearboxes with hand wheels, requiring no external power source; but would trade speed and power for the simplicity of manual operation. The second could employ a heavier hydraulic system for an increase in load capacity; requiring motors, a pump and hoses. The third version could feature electric actuators with switches for a more refined look.
Design
Overview
This is where detailed work begins in earnest and the design materializes. After the customer gives the go-ahead, the engineer moves forward with calculations, solid modeling in SolidWorks, materials, finish and fastener selection, stress analysis (including Finite Element Analysis / FEA where needed, and MathCAD calculations), and creates a bill of materials. Design for Assembly and Design for Manufacture principles guide part selection and geometry throughout. Part numbers and drawings will also begin during this phase. Some long lead items may be ordered during this time. Each iteration is followed by a design review, and the customer can evaluate the compromises in each choice, and the design will be refined further until we are comfortable building the prototype.
Workbench Example: If the customer chooses the manual design, the wormdrive gearboxes will be sized, the hand-wheels selected, and the solid models imported into the welded table frame assembly. An off-the-shelf (OTF) tabletop will be selected, or the engineer will begin discussions with a woodworker about cost and estimate and the choice of wood, finish, etc.
Prototype Assembly
Overview
Once the design is ready, the physical prototype is built. Off-the-shelf components and fasteners are delivered, parts are machined and weldments are fabricated according to the drawings. Components and assemblies are checked for fit and operation, and parts and drawings are modified according to early lessons learned. Additional design reviews keep all stakeholders on the same page as the project progresses.
Workbench Example: The welded frame and tabletop are delivered, and the table is assembled and the gearbox/handwheel assemblies are mounted and tested. Several notes are taken for modifications.
Testing
Overview
If necessary, some projects include a testing phase to confirm performance expectations, reliability of operation, how the assembly endures vibration and abuse, and to provide enough cycles to estimate a service life of the assembly.
Workbench Example: Possible tests: 1) raising, lowering and tilting the workbench under 1000 lb distributed load to test for stability and center of gravity; 2) installing stepper motors and writing a test program for full-range endurance testing of the gearboxes under load to estimate service life. 3) Drop testing loads on the edges of tabletop to simulate everyday use and test the linkages and gearboxes for toughness under impact loading. Testing may reveal that the gearboxes or frame are over or underspec'd for the application, and changes may be made.
Drawings & Documentation
Overview
All projects are documented; often in parallel during the Prototype and Testing phase. Depending on the contract, the customer may opt to buy only the prototype, or the entire package of complete manufacturing drawings. Drawings typically include all individual parts, components and weldments, and the parent assembly drawings as well, listing all the fasteners and off the shelf components and where these components were sourced.
Workbench Example: Drawings include the parent workbench assembly drawing and the BOM of all fasteners and off-the-shelf components and purchased subassemblies, the gearboxes, and all component drawings such as the wooden tabletop, drawers, shrouds, or accessories.
Manufacturing and Field Support
Overview
Support can be provided for any project, regardless of application. In the case of a manufacturing customer, the engineer is available to offer technical assistance and documentation management as the manufacturer makes further changes to drawings to make the assembly more efficient to manufacture. Tolerances, materials, and dimensions may all change based on manufacturing feedback.
The best testing environment is the actual application. Draeger Mechanical is available to provide further technical support for the customer if desired.
Workbench Example: The manufacturer may source a more economical alternative gearbox for the workbench, and may pay for additional testing of this new component. The manufacturer or retailer may also request an alternative design of 3 separate bolted subassemblies, to optimize for shipping and reassembly after delivery.