2. Project Overview CNC Introduction Applying CNC Designing for CNC
CNC Manufacture
Open Design for CNC Challenge
Total VEX Robotics manufacture

3. LESSON 05

4. Lesson 05 Starter
Learning objective: Apply sketching and ideation techniques to develop solutions to the challenge, problem solved through sketching, and developed a CAD file for fabrication of the solution (prior to fabrication and post processing)
Your design challenge Using sheet metal fabrication, redesign the VEX Tumbler into a rough and tumble super hero worthy road machine. You must cover the cortex and battery areas, and protect the wheels from being touched as the Tumbler drives over difficult terrain. The finished fabricated parts must fit the existing VEX parts, matching their tolerance and design aesthetic.
NB: this robot use alternative 5 inch wheels. For this challenge the VEX Clawbot (with tower removed) is appropriate to create a Tumbler style basebot.
Key words: CAD, Library, heat processes, acrylic, MDF, profile, forming.

5. Open Design Challenge CNC design challenge
Using the A3 template sheets, sketch solutions, including specific Tumbler parts in both 2D and 3D, to create your unique robotic solution. Consider the key aspects of the design brief: - protecting the electronics - protecting the wheels - being able to take on tough terrain Consider conducting research into other Tumbler style vehicles and military solutions to inspire your design. Extension Add annotating specific locations of connectors, fixings and other VEX elements.

6. Open Design Challenge CNC design challenge
Build a card model. Using simple card modelling techniques, tape, and cutting tools, create your Tumbler components to scale built over your Tumbler basebot. Review your model, and plan where bends, connectors, issues with the assembly, and potential material savings can be made in your design. Once you have photographed and analysed your Tumbler, lay all components out flat on a sheet of paper, and note the specific dimension of material you will need to build your Tumbler.

7. Open Design Challenge Model Making
Here a Tumbler is going through model making stages. Note that parts are cut and joined individually and as “nets” so that the right sizes, aesthetic and assembly is achieved.

8. Open Design Challenge CNC design challenge
CAD your individual components. These will need to match the high tolerance specific components you planned earlier in this project. Consider: - tolerance - fit - material reduction - waste reduction - speed of manufacture - ease of bending - ease of assembly - reducing post processing

9. Open Design Challenge Designing parts
Once you have designed individual parts, group them into a complete set needed to fabricate your robot solution. Where possible, minimise wastage of material, either by overlapping cuts, grouping parts close together, or lining up parts in one direction to take up less sheet space. Remember the less lines being cut will mean less time taken to produce the set.

10. Open Design Challenge CNC design challenge
Fabricate, post process and assemble your design solution. Task Once parts are cut, finish and form them (remember your post processing worksheet from the previous lesson), before assembling them. If you can, spray paint and enhance their appearance with finishes beyond those available for VEX. Finally test your product, and see if you meet the design brief?

11. Open Design Challenge Final outcome
Build your final outcome and set up a suitable test… Consider the roll of the Tumbler and its protective body armour: - prevent access to the vulnerable brain and wireless key - provide access to key parts - drive sufficiently over terrain Task: Test your Tumbler by devising some specific tests for each of these criteria, and personally grade your outcome.

12. Lesson 05 Plenary
As a class, let us consider the following questions? A. How can we sketch ideas to look suitable for CAM? B. What annotation should we include around a CAM part sketch? C. Do we need to sketch in 2D or 3D, or both? D. What are the features of good sketching and design for CAD/CAM?

13. Lesson 05 Summary Today you have:
Learning objective: Apply sketching and ideation techniques to develop solutions to the challenge, problem solved through sketching, and developed a CAD file for fabrication of the solution (prior to fabrication and post processing)
Today you have:
Identified a solution, sketched the solution, and produced a CAD file for its fabrication
Assessed designs and thumbnail sketches prior to CAD development
Produced a part through CNC machining