As Bag-N-Tag days go, this last on was not so bad. We managed to get the robot bagged by 10 pm, after only a couple days of actual manufacturing. Granted, the whole robot is not there – it’s missing the intake mechanism (which needs some redesign) the gearbox for the arm module (which was too expensive to build two – and also needs redesign). But the whole process of designing the robot from wheels up in CAD before ever cutting a single part or linking a single chain is one that many manufactures practice every day. As part of my day job, I’ve been reading a lot about computer-aided design, manufacturing and inspection. Here is the general running theme.
Manufacturing industries have been directing their efforts to decrease the cost of the products (no duh right?). Not only are they attempting to decrease their cost, they are trying to deliver a more economical product, keep up with increasing demand, meet insistence on higher quality, better performance, and timely delivery schedules. What is worth mentioning, and something that as a coach of a high-school level robotics team I didn’t fully appreciate, a substantial fraction of these companies total cost of any product depends on design procedures or techniques. In fact, 70% to 80% of the manufacturing costs of the product depend on the design decisions while production decisions only contribute about 20% to 30% (yeah, don’t quote me on that – but I read it in a book which referenced another book).
What is Design?
Design can be defined as a process of developing a system, component, or process to meet the customer requirements. It is the decision-making process that involves the implementation of basic science, mathematics (yah math!), and engineering technologies to transform resources to achieve the desired goal. In other words, poor design -> fail. So what are some of the reasons for poor engineering designs? J. Walton, Engineering Design: From Art to Practice, suggests the following six reasons.
- Inappropriate and unnecessary assumptions
- Lack of sufficient information or the understanding of the problem
- Erroneous design specifications
- Incorrect design calculations
- Inadequate data collection and experimentation
- Incorrect drawings, etc.
In the past six weeks I think I have seen five of these. And you know what, I’m glad I did. Each one stands as an opportunity to learn and get better. Part of my focus as a coach will now include working with students to better understand how these issues cropped up and to hone practices and procedures that help mitigate these issues in the future.
What is Manufacturing?
Manufacturing is a process of converting raw materials and design information into finished components to the satisfaction of job requirements. During the manufacturing phase, we seek to
- Minimizing time
- Minimizing waste
- Maximizing quality
- Maintaining flexibility to change in product, production, process, equipment, and personnel
A product design that cannot be successfully achieved through the available manufacturing process is a poor design. Similarly, the manufacturing processes are ineffective without reasonable design and plan.
And then there is programming… well more on that later.
As we get the practice bot together, recover from the CNC loosing it’s mind and destroying several feet of aluminum tube, Walter loosing his mind and having to redesign parts of the intake, Chaski still struggling with the arm gearbox design (with Rob breathing down his neck), Nick struggling with calculus (and getting ready for college – no worries Nick – the struggle is real), Peter wrangling code for a robot he can’t work with yet, and everyone’s general lack of sleep and growing frustration – Remember – we are building the next generation of the best engineers this planet has.