Lesson video

Hi there, everybody.

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

We've got a great lesson coming up, so I'm delighted that you have joined me.

Today, we're gonna be looking at design for additive manufacturing with Fusion and looking at all those rules and considerations that you need to have before you send a design to be 3D printed.

This lesson is part of the systems approach to design sustainable futures unit.

Today's outcome.

I want you to prepare models for 3D printing, taking into account the environmental impact of the materials used.

We have a few key words for you today.

The first is DFM.

This means design for manufacture.

Those considerations that you have to think about when designing and how you will manufacture your product.

We then have FFF, fused filament fabrication.

This is the type of 3D printing you are most likely to come into contact with when you're in school.

We then have filament, the thermopolymer material used by 3D printers to create objects.

We have fillet, adding a round to the edge of a solid body.

And then of course, body, a single continuous shape in Fusion.

Two learning cycles today.

The first is all about designing for manufacture.

And then we'll have a look at how you can prepare your model for 3D printing.

So let's get on with the first learning cycle.

When designing, it is important to take into account how the product will be manufactured.

And this is exactly the same when we're using 3D printing.

Considering manufacture when designing can reduce manufacturing cost, minimize complexity to avoid unnecessary parts, use materials and processes that are practical, improve quality and consistency of those parts and components, and also speed up production.

We call this design for manufacture or DFM.

Most 3D printers in schools use a process called fused filament fabrication or FFF for short.

This is when heated material is passed through a nozzle building parts layer by layer on a print bed.

Let's have a closer look at fused filament fabrication.

Fused, each layer of the print is fused by heat.

Filaments, this is the material we use with fused filament fabrication printers.

And it's usually provided in a spool and we're gonna be using PLA.

And then fabrication.

Well, this comes from the Latin word, fabricationem, which means structure, construction or making.

So you can see where we use, the way we use that for fused filament fabrication.

What does FFF stand for? Quick check for understanding.

Is it A, fast filament fabrication, B, fused filament fabrication, C, future filament fabrication or D, focused filament fabrication? Pause the video now, have a go at this and come back to me when you've got your answer.

It is of course, B, fused filament fabrication.

Well done with that.

There are basic DFM rules to follow when producing models for fused filament fabrication.

Following these rules will ensure that prints are successful and high quality.

There really is nothing more frustrating than coming back to a 3D printer after an hour to find out that your model has failed.

Material is kept to a minimum.

Unnecessary complexity is removed and parts fit together as expected if you have an assembly.

Now we're gonna focus on the base component.

And the reason for this is because this is the component we are going to 3D print.

We're not obviously gonna 3D print the micro bit cause that's a bought in item.

And also we've used a recycled punnett for the greenhouse section.

Now we do need to consider design for manufacture when we are looking at the base.

The micro bit and battery pack holders have been added and each DFM rule can be checked in the assembly.

And we can use the assembly in the timeline to be able to do that.

Now, what we need to do in Fusion is make sure that the base component is active and we're gonna hide all the other components in the browser so we can just focus on this component.

So that's important to be able to do.

So first of all, we're gonna look at overhangs.

Now component overhangs have to be considered.

The print issues you will have.

You will have reduced quality for any overhangs that are greater than 45 degrees.

And if you do have overhangs that are greater than 40 to five degrees, then what you need to do is use supports which increases complexity and can even waste material.

And that's a real problem with 3D printing.

So we don't really wanna do that.

So what considerations can we have? What design considerations can we think about? Well, first of all, reduce or remove all overhangs over 45 degrees if you can.

If not, maybe consider the orientation of the component when you are printing it.

You might be able to reduce some of the overhangs just by rotating your component in a different way.

Let's have a check then of our base components.

Well, the Punnett slot has an acceptable overhang of minus five degrees.

And this can be checked in the timeline edit feature.

So if we go to this feature that we've created, which is actually a thin extrude, we can see that in the dialog box right there, we have got a taper angle of minus five degrees.

So that's absolutely fine for a 3D printer to be able to cope with.

Quick check for understanding, which overhangs are suitable for FFF? We have A, 15 degrees, B, 45 degrees, C, 60 degrees, and D, 90 degrees.

Select all the ones that are suitable.

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

It is of course, 15 degrees and 45 degrees.

If we go over that, then we're gonna have a little bit of a problem.

We need to think about wall thickness as well.

So let's see the considerations.

So the print issues.

Walls less than 1mm thick will be weak, especially on a component that has to take some kind of force.

Walls greater than 2mm thick will increase material use and also print time.

So that can also be an issue.

So can some considerations for you.

Print walls between one and 2mm where possible.

Fixing points might need to have walls greater than 2mm, and that's absolutely fine.

It's a necessary that you have to do.

And you might also find that you have to have other walls thicker than that.

So if you do need to create walls that are greater than 2mm, then make sure you use a low fill percentage when slicing.

And most slicing softwares will do this.

So they'll have a honeycomb structure inside those walls, usually with only about a 15% fill.

Once again, let's check the base component.

So all walls are 1.

5mm thick.

And once again, we can check this in the timeline and edit feature.

So what we're gonna do is look at some of these walls here.

at some of these walls here.

And if I look once again at our tapered punnett holder, you can see right there, it is 1mm thick, thin extrude.

We're gonna have a great print time, but we've got enough strength for it to hold the punnett in place.

Now, the fixing points, they have to be greater than 2mm because we are gonna apply a steel fixing into there.

So I need those to be greater, and that's absolutely fine.

And we'll also consider the infill density when 3D printing those parts.

Now, tolerances vary depending on the printer that you are using and you've got to check those tolerances.

Print issues, parts that interact might not fit.

Hole tolerances can vary widely, so you need to think about those as well.

So here are some considerations.

Print small test pieces to check tolerances.

Don't print the whole model to check, just print a small part of that.

Print holes vertically so they are facing up, not to the side.

Fused filament fabrication 3D printers cope far better with holes that way.

Add chamfers to holes so fixings locate easier, and that will save damage of your parts.

Now you can see here, when I was thinking about how to fix the micro bit to the base component, I wanted to get my holes correct so I could fit my 3mm fixing in correctly.

So what I did is I printed a test component, and you can see here, it's got eight different holes on it of different sizes.

And I actually found that the 3mm hole diameter worked the best, I could insert the screw and take the screw out without it damaging anything.

And that print took about 20 minutes rather than printing an entire base model, which will take about an hour and 20 minutes.

So that's a great idea to do if you wanted to try out some test pieces.

So let's have a look at adding a chamfer, because I said we need to add a chamfer to make sure that the screw locates into the hole correctly.

So first of all, when we are in our base component, we're gonna click chamfer and modify from the modify toolbar.

Once we've done that, what we're gonna do, is we're gonna select the two edges that we want to chamfer.

And I'm gonna add a 1mm chamfer to this, and you'll see it's two edges and it's equal distance.

That means we're gonna go down 1mm and we're gonna go across 1mm.

We're gonna remove that material.

Once I'm happy with that, I press enter, and it's as easy as that.

Now, component joints can be weak where two bodies meet.

So print issues, joints will be weak and they can fail, especially with small wall thicknesses.

Quality is reduced on sharp edges.

3D printers just don't like sharp edges.

So there are some considerations for this as well.

First of all, you can add fillets to where bodies join.

That's a really good and easy way to solve this problem.

Also, it's useful to add a 0.

5mm or a 1mm fillet to all edges.

That's another really useful aspect you can do.

And you'll see, these were some test prints that I made early on, and you can see they failed and they failed quite easily.

And that's simply because I didn't have any filets between where the two bodies join.

So you can see that is an issue and you don't want that to happen on your final model.

So it's a really good habit to get into is to add some fillets.

So let's look at how we can add some fillets really easily.

Well, first of all, we need to click filet in the modify toolbar.

Once we've done that, we need to select the edges that need increased strength.

So for this, I'm selecting where my fixings are gonna go.

I'm also selecting the tapered angle of the extrude where the punnet's gonna go, and also the inside of my battery holder.

I'm then entering 2mm into the dialog box once I've selected all those edges, and then I'm clicking okay.

And that's a nice, easy task to do.

We can then add a fillet to the entire model as well.

The first thing I need to do is just make sure I've got the window selection.

So just go to the select toolbar and just make sure you've got window selection selected or press one on the keyboard.

That's a nice, easy shortcut.

I then highlight the entire model.

Once I've highlighted the entire model, I'm gonna click fillet from the modify toolbar and then enter a 0.

5mm fillet and press enter.

And that's a nice and easy way of doing it.

The 3D printer will now be able to cope with it really well.

So quick check for understanding, which button do you click to fillet? Is it A, B, C, D, E, or F? Pause the video now, have a go at this and come back to me when you've got your answer.

It is, of course, B.

You can see it has taken a fillet off the edge of that cube.

You can see on the symbol.

So we're now onto your first task.

I want you to edit your base component, taking into account 3D printing DFM rules.

No overhangs over 45 degrees, no unnecessary bridging or support structures.

Wall thicknesses are between 1mm and 2mm where possible.

Fillets and chamfers added to joints and edges and hole tolerances have been checked.

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

So how did you get on? Well, I'm sure your model looks something similar to mine and that's great because it's now ready to be 3D printed.

So we're now onto our next learning cycle, prepare a model for 3D printing.

First, we're gonna export the component for 3D printing.

So first of all, we're gonna right click on the component we wanna export.

In this case, it's the base component.

Once we've right clicked on that in the browser, we need to select save as mesh, which is down there.

A few options we need to check.

First is the format is STL, the unit type is millimeters and the refinement is high because I want a decent prototype.

Once we've done that, I'm gonna click okay and I'm just gonna check the little box that says, Save to my computer 'cause then I can import it into my slicing software.

Once you've done that, click Okay.

Quick check for understanding, what file type is exported from Fusion to a slicing application? Is it A.

stl, B.

jpeg, C.

MP4 or D.

png? Pause the video now, have a go at this and come back to me when you've got your answer.

It is of course.

stl, well done.

The STL file format is the most commonly and widely supported file type for 3D printing used with most slicing applications, but you do need to check that.

So check in your slicing application which is the best format to use.

The component will be oriented as it's seen in Fusion.

Remember that 3D printers like to print wide rather than printing tall.

So formatting it in that exact same position is absolutely fine.

Bed adhesion is not needed due to the large surface area in contact with the print bed.

This is not going to fall over when printing.

And finally, we are going to heat the print bed.

That is needed because we have a large surface area and some of those walls are quite thin and we don't want it to warp as it cools.

For this prototype, the default settings for draft print can be used.

And in my slicing software, this is what they look like.

So I'm using a 0.

4mm diameter nozzle.

That's pretty much standard with a lot of FFF printers.

The filament, well, I'm using recycled matte PLA.

The layer height, I'm doing it draft.

So I'm using a 0.

24 millimeter layer height.

Wall loops.

So this is how many walls we're actually gonna have.

I'm having two of those and that's for a little bit of strength.

Supports, I don't need any because I've got no overhangs as we found out previously.

The print temperature is gonna be 220 degrees centigrade and the bed temperature is gonna be 60 degrees centigrade.

The print summary of this.

Well, the filament used is gonna be about 23 meters.

That sounds a lot, but actually it's not that much.

And also it's 73g of filament and that's about a cost of about £1.

84.

The total print time for the entire base model is one hour and 17 minutes, which I think is pretty good.

So let's have a look at a fused filament fabrication 3D printer.

These are the features.

So we have our filaments which is fed into the print head and heated up.

That is then pushed through the nozzle onto the bed to create the model.

And of course our print bed is heated and our filament spool is usually positioned next to the printer.

Quick check for understanding.

I want you to fill in the missing labels of this FFF 3D printer.

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

So the missing labels were of course filament, nozzle and print bed.

Well done.

Now the choice of filament can affect the prototype's environmental impact.

As we 3D print more and more products and prototypes, we need to consider the environmental impact of the filament we're using.

Many filaments are made with new polymers that can be difficult to recycle, adding to the polymer waste and landfill that we already have a huge problem with.

So the circular economy should be considered when selecting 3D printing filament.

And if you think about that, when we're selecting 3D printing filament, we're thinking about raw materials, design, we're thinking about manufacturing materials processing, but even things like repair and maintenance and also back to the recycling and waste.

So it covers a lot of the circular economy.

So that's got to be considered.

So the circular economy should be considered when 3D printing and choosing 3D printing filament.

Some of the issues, use of new thermopolymers, increase in polymer waste and landfill.

So what considerations have we got? Well, use recycled or biocomposite PLA filaments.

Use filament with 100% recycled cardboard or reusable spools.

We can also use 3D printing waste recycling schemes.

And that's a really good way to reduce the environmental impact of the materials we are using.

So now onto task B.

First of all, I want you to explain why the choice of filament can affect the environmental impact of 3D printed parts.

I want you to export your base as a.

stl file, import the.

stl file into a slicer application of your choice.

Use the slicing settings of your choice based on the materials and machines that you have available.

Check the slicer preview for errors.

Most slicers have a preview.

3D print your base and then finally check it for quality.

Pause the video now.

Have a go at this task and come back to me when you've completed it.

So how did it go? Well, let's first of all, have a look at a sample answer for the first question.

Explain why the choice of filament can affect the environmental impact of 3D printed parts.

Well, many filaments are made from new polymers that can be difficult to recycle, contributing to polymer waste and landfill accumulation.

By using recycled or biocomposite PLA filaments, 100% recyclable cardboard spools and implementing 3D printing waste recycling schemes, the environmental impact of 3D printing can be significantly reduced.

And then finally, we've got your 3D printed base and it might look something like mine, hopefully even better.

You can see this is a really good quality and it's even on draft setting, but you can see I've got my chamfers and I've also got my fillets, which is gonna increase the strength of my product.

Well done.

So that brings us to the end of this lesson.

Let's have a quick summary.

When designing, it's important to take into account how the product will be manufactured.

There are basic design for manufacture rules to follow when 3D CAD modeling.

It's important to know the capabilities and limitations of 3D printing when designing.

The circular economy should be considered when selecting 3D printing filament.

3D models need to be prepared for printing using a slicing application.

You've been absolutely fantastic today.

It's been great to do this lesson with you.

I hope you enjoyed it and I will see you all next time.

Goodbye.