Lesson video

Hi there everybody.

My name is Mr. Booth and welcome to your design and technology lesson for today.

It's fantastic that you could join me.

Today's lesson: Assemble, test, and refine systems. And the system in question here is of course our greenhouse system.

This lesson is part of the Systems approach to design: Sustainable Futures unit.

Today's outcome, "I can assemble and test a system to inform evaluations and modifications." We have three key words for you today.

The first is testing, measuring against design requirements.

And those design requirements can come from a number of different places, including design specifications, manufacturing specifications, or even a design brief.

We then have modifications, making changes or adjustments to improve.

And finally, evaluations, judgements based on testing findings.

We have two learning cycles today.

The first is all about assemble and test systems, and then we can evaluate and modify those systems. So let's get on with the first learning cycle.

The context in this unit is sustainable futures.

Izzy wrote a design brief for the context, so let's have a look at that design brief once again.

"I am gonna design and make a control system to manage a greenhouse.

The control system will monitor and maintain the optimal conditions for the plants to grow and thrive." Now Izzy needs to assemble and test her system to see if she has satisfactorily covered all those aspects in the brief.

To fully assemble and test her system, Izzy will need 3D printed base, a recycled punnet as the greenhouse, a micro:bit and battery holder, the system program downloaded onto that micro:bit, all the offboard input and output components that she would like to use as part of her system, the fixings to hold all the parts of her system in place, soil pellets, which of course we're then gonna grow the seeds in.

Once the system has been fully assembled, it can then be tested, but it's got to be fully assembled first.

So let's once again have a look at Izzy's system.

So first of all, she's got her recycled punnet.

The planted seeds are inside the soil pellets.

We've got the fixings holding the micro:bit in place.

We've got all the offboard components, the 3D printed base there as well and also the programmed micro:bit and battery holder, making sure that the batteries are charged or they're new, and also that the program actually works on the micro:bit.

Now of course, your system will vary depending on the components, the systems and the design that you have chosen.

This is here just for the example.

Testing is important throughout the whole iterative journey, such as virtual and physical testing of electronic systems, virtual and physical testing of the programs that you're going to be using, digital assemblies to check on tolerances such as whether fixings are gonna fit in place, and of course, testing 3D printed samples for fit and quality.

Again, this could be done for the fixings.

Quick check for understanding: How could the whole diameter for the fixings be tested? A, 3D print a sample part and assemble the components, B, assemble the components in CAD, C, 3D print the final prototype and assemble components? Pause the video now.

Have a go at this and come back to me when you've got your answer.

It is of course 3D print a sample part and assemble components or assemble the components in CAD to check the fit.

You wouldn't wanna 3D print the final prototype and assemble the components, because if it was wrong, you've wasted a significant amount of material and time by printing the entire part.

Testing is required throughout the iterative journey to ensure a successful prototype is developed.

You've gotta make sure you're doing it at regular intervals.

So we do lots of testing.

We then make some design decisions and we do that multiple times throughout the process, and you will have done that as part of this process.

Once we've done that, we get a successful prototype, a prototype that does what we wanted it to do.

Testing after manufacture in school informs evaluations and final suggested modifications that we might have.

So we have our prototype, we still can carry out that testing.

But then what we've done is we can then do our evaluations and modifications based on that testing.

Quick check for understanding: Testing after manufacture in school informs evaluations and final suggested what? Pause the video now, have a go at this and come back to me when you've got your answer.

It is of course modifications.

Well done.

We're now onto your first task.

First of all, I would like to fully assemble your system on all the components that you are using.

I then want you to test your system, see if it works, carry out all that analysis when you're testing it.

When you do that, I want you to record your findings when you test it, what works and what doesn't work.

Pause the video now, have a go at this and come back to me when you've done this.

So how did you get on? Well, let's look at how Izzy got on.

So Izzy assembled and tested her system and recorded her findings.

"It was challenging to insert the offboard components through the punnet.

The program worked as expected with the micro:bit sensing the light levels, the soil moisture, and the temperature.

But the LED display was difficult to read due to the angle at which it was secured to the base." So we've got some really interesting findings there and I'm sure you have too.

Well done.

So we're now onto your second learning cycle.

This is all about evaluate and modify.

So let's get going.

Evaluations are judgements based on the findings of testing.

Testing measures against the design requirements set out in the brief.

Let's have another quick look at that brief when we've highlighted those requirements.

So we wanted to create a control system.

It had to manage the greenhouse in some way.

And to do this, it needed to monitor and maintain these optimal conditions for plants to grow.

And we can see that Izzy has obviously tried to do that through temperature, soil moisture, and also light levels.

Evaluation is required throughout the iterative journey to ensure that successful design decisions are made and a successful design solution is developed.

So again, we do our testing, we then evaluate and then we make some design decisions, and once again, we can do this multiple times as part of the iterative process.

Eventually you will run out of time.

But if you do this a few times, you're then gonna have a prototype which is more successful.

Quick check for understanding, evaluations are judgments based on the findings of what? Is it A, design decisions, B, a manufacturing specification, C, modifications or D, testing? Pause the video now have a go at this and come back to me when you've got your answer.

It is of course D, testing.

Well done.

Evaluations after manufacture in school informs final modifications.

So we can imagine that Izzy has manufactured the final prototype.

We have it there and we've assembled it.

It's then being tested.

All the systems have been tested to see whether it works and the functionality of it.

We then can evaluate that testing and then we can suggest any modifications we think will improve that prototype.

Final modifications should naturally develop from evaluations after manufacture.

These modifications are suggested and do not need to be manufactured.

Now, evaluations will identify many areas of modifications.

For example, material.

Did we actually use the correct material for this product? Is it durable enough? Is PLA durable enough to be able to hold that soil and also the moisture that's gonna be in there, or should we have used ABS instead? But if we'd used ABS, of course there's a environmental issue with that because it's probably a new plastic rather than recycled PLA.

PLA also is biodegradable under certain conditions.

So that would be another consideration that we might want to make.

Manufacture as well.

Did we really manufacture as efficiently as possible using our 3D printer? Could we have modified the model to use less material or to print faster? We also have the aesthetics of the product.

Does it actually matter what the base looks like? It might do.

Now Izzy has 3D printed it in a white PLA.

Is that sensible, considering we're using it as like a garden, so we're putting soil in it.

Would it be better if we used a darker color? We need to think about safety as well.

Actually, is this okay for the micro:bit to be next to somewhere which has moisture in it? So we could consider that as well.

Technology.

Is there a better way to 3D print this? Is there a better 3D printer we could've used? That's under consideration.

And then finally we've got things like ergonomics.

Well, Izzy already discovered an ergonomic issue with this.

She struggled to read the screen because it's facing upwards rather than facing at the user.

So that is another consideration that could be for modifications.

Now, successful modifications suggest an improvement.

They need to be justified.

They have to originate from evaluations and relate to the testing that you carried out.

And they should always address the design requirement from the brief.

Quick check for understanding.

Successful modifications: A, are generated by your own thoughts only, B, address design requirements, C, address primary user stakeholder expert opinions or D, provide justification.

Pause the video now.

Come back to me when you've got your answer.

So it is of course B.

They address the design requirements.

C, address primary user, stakeholder, expert opinions and also D, provide justification.

Well done.

Suggested final modifications can be presented using a variety of methods, and these methods include explanations.

We could just explain what we're gonna do.

We could do some sketches.

These could be quick sketches to suggest improvements.

We could even take a picture of our model and then sketch over the top of it for the modifications that we are gonna suggest.

We could go back into Fusion and actually do some CAD drawings or do some more simulations.

We could create a scale prototype of a certain aspect of a modification that we want to address.

We could also use tables and charts.

So we're now onto your final task, task B.

I want you to evaluate your testing and identify modifications for your final prototype.

Suggested modifications should be justified, originate from evaluations, relate to testing and address design requirements from your brief.

I then want you to present your modifications using any of the following methods: Explanations, sketches, CAD drawings or simulations, scale prototypes or tables and charts.

Pause the video now, have a go at this task and then come back to me when you have completed it.

So how did you get on? Well, let's have a look how Izzy got on.

So Izzy evaluated her testing and identified modifications.

It was challenging to insert the offboard components through the punnet.

So she suggested a modification here.

"I will make modifications to the punnet so the offboard components can fit through.

A small 3D printed part could hold the wires in place.

The parts can be attached to the base component." That's a great idea.

The LED display was difficult to read due to the angle at which it was secured to the base.

"I will modify the angle of the micro:bit holder on the base component to tilt the micro:bit towards the user.

This will make the LED display easier to read and interact with." And that's another great idea and Izzy is now gonna present that.

And she presented it by modifying her CAD model.

Now she doesn't necessarily have to 3D print this, but it's a great way to present it and show how the design will be modified.

Well done with that task.

I'm sure you've done a fantastic job as well.

So that brings us to the end of this lesson.

Let's have a quick summary.

Prototype testing can be used to inform evaluations and modifications.

There are a variety of methods to test prototypes.

Whilst testing, modifications may be identified.

Evaluations are judgments based on the findings of testing.

Successful modifications are justified and originate from evaluations.

Well done today.

You've been absolutely fantastic.

I look forward to seeing you all next time.

Goodbye.