Introduction - Is working backwards a way forward?
One of the main attributes of practical engineering education is students interacting with real things. When this teaching specifically involves experimentation in a laboratory setting, the real things typically include items such as equipment, tools, specimens and various types of instrumentation. There is a varying degree of openness for laboratory activities, ranging from students following detailed step-by-step guides, to them independently conceiving, designing and executing their own experiments. But in order to ensure consistency of experience for everyone in the course, the equipment and instrumentation students use is typically selected and provided by the university for one specific purpose.
Despite equipment being at the very centre of practical laboratory activity, the pedagogy (or method of teaching) associated with its selection and design is often overlooked in the learning and teaching development process. This may be due to the fact that the typical starting point for designing/specifying new laboratory teaching equipment is based on determining the physical concepts (phenomena) that need to be demonstrated or investigated. This is certainly the case when looking through catalogues of educational equipment suppliers, where the organisation and focus is placed on what experiments can be run on their products rather than what learning can be extracted from them. What we propose here is an alternative way of approaching the specification of laboratory teaching equipment, one based upon learning outcomes (LOs).
Top - Working from a phenomena of interest, Bottom - Developing based on LOs
Start with what learning you want to achieve - a new model
Our approach is to begin all laboratory design projects with clearly defined LOs, these could be multiple or singular, depending on requirement and encompass any specific lab competencies required. The second stage is to then couple this framework with a fully integrated design team with areas of expertise relevant to achieving the project objectives. This typically consists of a mixture of academic and technical members, but also can accommodate industrial partners if relevant to the target LOs. These steps effectively create a ‘constructive alignment’ (a focus on the LOs) that propagates not only through the teaching aspects but also through the entire design and manufacturing process too, avoiding the pitfalls of the purely phenomenological (or demonstrating physics) based design approach mentioned previously.
Not only does the output of this process result in a richer experience for the learner (they get cool, educationally relevant stuff to play with), at the same time it also greatly increases efficiency of the teaching effort in general as content is generated automatically at each step of the design process. With only small amendments, technical specifications, briefs and calibration data can be modified to create student lab sheets and metrics for pre/post lab activities. In addition if 3D geometry was created as a part of the design process (which it typically is these days) this can provide a plethora of options tied to the learning experience, such as manipulation of 3D models in normal/VR spaces for training/ visualising concepts, computer simulation (i.e fluid dynamic CFD simulation/ FEA structural testing) and also allowing students to use/adapt these models in their own design projects for teaching (see Fig 3).
Figure 2 - Comparison of off the shelf versus in house variants.
Left - Gunt’s HM 135 - Determination of the settling velocity apparatus, Centre - A custom built piece of equipment that can perform similar experiments, but is cheaper, reconfigurable, and easier to store/service. Right - The same apparatus, but reconfigured to look at the effects of movement at predefined forces (different weights).
Left - An lab sheet example of vector based content generated from the 3D CAD used to create the equipment, Right - A browser based fully interactive html5 3D model embedded in the VLE (Blackboard), again generated from CAD geometry. Click here to load: 3D Model
Pros & Cons
Some of the benefits and drawbacks of the proposed model of equipment development are discussed below, see Figure 2 for an example comparison.
The benefits of build your own kit for Practical Engineering Education:
Fully bespoke equipment tailored to LOs
Any outputs from the equipment are guaranteed to interface with the curriculum set out for the students.
We are engineers
Design and development is part of what we do with the department, this methodology ensures we make the most of our time and effort.
Cheaper
Keeping Design/R&D in house (on campus) reduces costs, as external companies have overheads that are passed on to clients i.e. Marketing costs. Also potentially paying for features that don’t contribute (or at worst detract) from learning.
Maintenance
Designs can be made more robust without design for failure, reducing maintenance costs. Control systems can also be constructed from individual components, rather than paying for pre-made solutions, these parts can be replaced cheaply (if you know how it works), with no maintenance contracts or call outs to pay for.
Increased student participation
Students can get involved with the design process or help to inform it with feedback. Also some teaching modules based around the ‘design, build and test’ maker premise can fabricate parts for testing that interface with the equipment design.
Customisable/Modular
Equipment can incorporate greater modular aspects in the design, this can make it flexible to adapt to new learning objectives in the future (Fig 2).
Industry standard instruments
Use examples of pumps or heat exchanges for above two points., where the instrumentation is built into the equipment and you don't alter it or investigate what it is or how it works.
Why buy from suppliers or design for phenomena first:
Fully bespoke equipment tailored to LOs
This can be a double edged sword, if the equipment or LOs are too niche re-usability in the event of curriculum change can be limited. Careful modular design is very important to avoid this.
Off the shelf
Equipment from suppliers is quick to obtain and comes with resources, lab scripts and calibration certificates and CE marking/safety features.
The equipment works
When building your own products, there is always a danger that you will spend a lot of time and not develop a working product. If you buy from a reputable supplier, it’s guaranteed so the risk is very low.