Autodesk car design

F1 in Schools Autodesk Inventor Professional 2016

Design Guide

Contents Introduction Creating a New Part in Inventor Saving the Part File Creating Sketches Vertical Reference Plane Guide Sketch Wing and Wheels Guide Wing and Wheels Above Guide Virtual Cargo Guide Virtual Cargo Guide Vertical Reference CO2 Chamber Guide Car Body Side Profile Extrude Side Profile Model Base Extrude Model Base Wheel Hubs Axle Holes CO2 Chamber Closing the Cartridge Hole Rear Wing Mount Front Wing Mount / Tail­stock Filleting Tether Line Slot Drilling Axle Holes Create New Assembly Place Part Create Part in Place Axle Bush Pattern and Mirror Wheels Rear Wing Front Wing Tether Line Guide Exporting STL's Axles Calculating Weight of Model Adding Material Properties Adding Decals Drilling Axle Holes CNC Program

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Introduction The aim of this guide is to illustrate a way of designing a car to compete in the F1 in Schools Technology Challenge which complies with the rules and regulations.

The author of this guide works for Denford Ltd and has good knowledge of the machining process.

The techniques shown in this guide are by no means the only way to create a design, but the methods have worked well for the author and are offered as a helping hand to get you started.

This guide uses the 2015 / 2016 Technical regulations and Autodesk Inventor Professional 2016 on Windows 10.

There is also an F1 in Schools Car Manufacturing Design Guide and a QuickCAM Pro Training Guide available, which will also assist you in the design and manufacture of your model.

The part files created in this guide are available as a download and can be used as a reference.

This guide makes use of screen shots, where possible, and will use the following conventions: Instructions will be in this format Any software buttons to be pressed, a picture of the button will follow the instruction This guide assumes that you are using Autodesk Inventor Professional 2016, some features may be different if using a different version.

Denford Ltd provide Car Manufacturing training and it is recommended that you undertake the training and use this guide as a revision after completion of the training.

The design in this guide has a weight of 64g according to Inventor. The actual car when manufactured has a weight of 58g. This discrepancy is likely due to the 3D printed parts being printed hollow.

This design recorded a time of 1.22 seconds, which would have been fast enough to have won at 3 of the UK regionals last year.

Good luck!

Creating a New Part in Inventor To start the design of your model in Inventor you will need to create a new part. You should create a Standard(mm).ipt Click the "Metric" folder Click the "Standard(mm).ipt" button Click the "Create" button

Saving the Part File It is recommended to save your document at different stages to protect against an accidental power off or reboot of your PC. As you will be creating a number of different parts for your design, it is a good idea to create a folder on your PC where you can save all those parts together.

This will make it easier to locate your components later.

Click the "Inventor" button Move the mouse down to the "Save" option

Move across to "Save" and click the "Save" button

Set the "Save in" location As you can see in the image on the right, I like to save to the Desktop.

Click the "Create New Folder" button Name the "New Folder" Double click on the "New Folder" to open it Type a "File name" for your part Click the "Save" button

Creating Sketches When creating a part in Inventor I like to create sketches as guides to assist in designing a part that can be manufactured to meet the specification.

Click on the upper part of the "2D Sketch" button Click on a plane (XZ)

Use the controls on the "View Cube" to adjust the view You want the X Axis running left to right and the Z Axis running from bottom to top ­ as the icon next to the view cube illustrates.

Vertical Reference Plane Guide Sketch Using the sketch created in the previous step, we are going to create guide lines to ensure our design meets the regulations.

Firstly we will draw a line for the ground plane.

Select the "Line" button

Starting from the origin (X0,Y0,Z0), draw a horizontal line to the left.

Click to place the line, then press the "ESC" key to end line drawing.

Next we will place a dimension on the line. The Dimension Tool is under the Sketch Tab grouped under the Constrain Section Click the "Dimension" button Click on the line you drew.

Set dimension to 209mm Dimension is set to 209mm as the Max Overall Length of the car is 210mm as specified in Critical Regulation T3.3 (­6 pts) and I am giving 1mm clearance to avoid a penalty.

I am aiming for maximum length in this design, as the longer an object is the more aerodynamic it is for the same frontal area.

Next you should draw a rectangle above the existing line. This rectangle will represent the billet and the previous line is the ground plane.

The rectangle should be 2mm above the Ground Plane as per Regulation T3.6 (­6 pts). I have drawn it 3mm to allow a 1mm safety margin.

The rectangle should be 50mm high as this is the height of the billet.

You should now also draw a rectangle within the billet to represent the cartridge hole. This should be 19.5mm in height and 60mm long, the centre line should be 29mm from the bottom of the billet.

Using the "Line", "Rectangle", and "Dimension" buttons.

Add the details shown on the sketch below to your sketch

A line can be converted to a centreline by selecting it and clicking the "Centreline" button.

Convert the centreline of the cartridge hole using the "Centreline" button.

Click the "Finish Sketch" button

It is a good idea to rename the sketch in order to keep your model organised.

Double click the sketch in the Model Browser and type in the name below: Press the "Enter" key to save the name

Wing and Wheels Guide We are going to add the wings and wheels later as 3D printed items for this design, but we must plan their location before we can design the shape of the body.

Wheel Diameter The smaller a wheel's diameter the less frontal area it will have. Critical Regulation T8.3 (­6 pts) states a minimum diameter of 26mm so I will design the wheels to have a 27mm diameter. This gives a 1mm margin.

Regulation T10.3 (­6 pts) states that the wing surface must have a minimum of 3mm clear space, so we will have 4mm between the front of the wheel and the trailing edge of the wing.

Rear Wing Location Critical Regulation T10.4 (­6 pts) states that the rear wing must be behind the centreline of the rear wheel, we will make it 1mm behind.

Critical Regulation T10.5 (­6 pts) states that the rear wing must be higher than 34mm from the track surface. We will make it 35mm.

Front Wing Location Critical Regulation T10.6 (­ 6 pts) states that the front wing must be in front of the centreline of the front wheels. Our wing will be in front of the front wheel.

Regulation T8.6 (­6 pts) states that the front wheels may only be obstructed to a height of 15mm from the track. We will make it 14mm.

Wings The longer an object is the more aerodynamic it is. Regulation T10.11 (­2 pts) states the maximum chord length is 25mm so we will make it 24mm.

Regulation T10.12 (­2 pts) states the Max thickness of the wing is 6mm. We will make this 5mm.

Regulation T10.12 (­2 pts) states the Min thickness of the wing is 1.5mm. We will make this 2.5mm.

Create the sketch shown below and name it Wing and Wheels. It should be created on the same plane as the Vertical Reference Plane

Wing and Wheels Above Guide We must now plan the location of the wheels and wings from above.

Wheel Width The narrower the width of the wheel the less frontal area it will have. Critical Regulation T8.4 (­6 pts) states a minimum width of 15mm, so we will make it 16mm.

We are aiming to get the smallest frontal area possible for our design. Critical Regulation T8.2 (­6 pts) states that the distance between opposing wheels must be a minimum of 30mm. We will go 31mm

Wing Span Regulation T10.9 (­6 pts) states that the minimum wing span is 40mm. We will make ours 42mm Regulation T10.10 states that the minimum span segment is 20mm, ours will be 21mm

Billet Size The Billet that the car will be machined from is 65mm wide. We should add this dimension to this sketch.

Create the sketch shown below and name it Wings and Wheels Above. It should be created on the XY Plane

Virtual Cargo Guide Virtual Cargo Critical Regulation T4.3 (足6 pts) states that a virtual cargo must be completely encompassed by the body and be wholly positioned between the front and rear wheel centrelines. This must also be clearly identified within the engineering drawings Regulation T4.5 (足3 pts). We will make all dimensions for the virtual cargo larger by 2mm as a safety margin to avoid penalties.

Exclusion Zones Critical Regulation T4.5 (足6 pts) states that no part of the car body must exist in a 15mm volume immediately rear of the front wheels. The volume is equal to the wheel width and wheel diameter. We will have a 16mm exclusion zone.

Visibility from Top Critical Regulation T8.5 (足6 pts) states that the wheel view cannot be obscured in any way, by any component of the car in the top, bottom, and side elevation views. A 1mm exclusion zone must be present in the top view. We will make this 2mm.

Create the sketch shown below and name it Virtual Cargo. It should be created on the XY Plane

I have chosen to place the virtual cargo as far back as possible to the exclusion zone in front of the rear wheels. This will give me more freedom in the shape of the front of the design.

Virtual Cargo Guide Vertical Reference Virtual Cargo Critical Regulation T4.3 (­6 pts) states that the depth of the virtual cargo should be 8mm minimum, so we will make ours 10mm to allow a 2mm safety margin.

Exclusion Zone Critical Regulation T4.5 (­6 pts) states that no part of the body of the car must exist in a 15mm volume immediately rear of the front wheels. The volume is equal to the wheel width and the wheel diameter. We will have a 16mm exclusion zone.

Create the sketch shown below and name it Virtual Cargo Vertical Reference. It should be created on the XZ Plane

CO2 Chamber Guide Regulation T5.2 (­2 pts) states that the lowest point of the chamber opening to the track should be a minimum of 20mm and a maximum of 30mm.

As we are using the Official F1 in Schools Model Block and have a ground clearance of 3mm, our CO2 Chamber is 22.25mm from the ground plane.

Regulation T5.4 (­3 pts)states that the thickness of chamber surrounds must be a minimum of 3.5mm ­ ours will be 4.5mm.

Create the sketch shown on the right and name it CO2 Chamber. It should be created on the YZ Plane

Car Body Side Profile To create my side profile I have started a new sketch on the XY Plane.

A set of guide lines would help us here to show the regulation dimensions. Luckily the guide sketches we created can be made visible to help us design within the regulations.

Create a new sketch on the XY Plane Right click on the Vertical Reference Plane sketch and make it visible Right click on the Wings and Wheel sketch and make it visible Right click on the Virtual Cargo Vertical sketch and make it visible Turning off dimension visibility may make the sketches clearer to view

Using the "Project Geometry" button and then selecting the parts of the sketches you wish to use as guides for your side profile enables you to then turn off the visibility of the sketches and makes the sketch view less crowded.

Click the "Project Geometry" button Select the lines you wish to use Turn off the visibility of all sketches except the current one.

Draw your side profile You may notice in the sketch below that I have ended my profile 2mm in front of the centre line of the front wheel. I have done this as from this point forward will be my front wing support and front wing.

Critical Regulation T10.6 (­6 pts) states that the whole front wing and any support structure must be in front of the centre line of the front wheel when viewed in the side elevation.

Starting the wing support 2mm in front of the centre line gives me a 2mm margin.

Click the "Finish Sketch" button when you have finished drawing your profile

Extrude Side Profile Now that we have sketched our side profile we will want to extrude it.

Click the "Extrude" button

If you have created a fully closed vector shape in your sketch then it should be selected automatically.

In the Extrude dialogue box, select the Symmetric option I have chosen to make this extrusion 15mm.

You can make it whatever size you wish, but if it is wider than the distance between your opposing wheels you may need to cut some of it away later. Do not extrude further than 65mm as this is the maximum width of the billet.

Enter the dimension of your extrusion Click the "Green Tick" button

Model Base Having created the side profile, we should create the model base next.

Create a new sketch, select the base of the side profile extrusion as your sketch plane.

Make the Wing and Wheels Above sketch visible Make the Virtual Cargo Above sketch visible Click the "Project Geometry" button and select the lines that you wish to use.

Turn off visibility of all sketches other than the current one

Extrude Model Base When you have completed the profile for the model base, exit the sketch.

Click the "Finish Sketch" button Click the "Extrude" button to extrude the base.

Make sure you extrude upwards.

As we have to attach a decal to the side of the vehicle, as stated in Regulation T4.6 (­6 pts) we should extrude at least 15mm so that the decal fits. We will extrude 16mm.

Wheel Hubs The wheels will need to be mounted. Next we will create an extrusion that will act as the wheel hub.

Create a sketch on the XZ Plane It will be necessary to change the view so that you can see hidden edges as this sketch is within an extrusion.

Click the "Visual Style" button and select Wireframe with Hidden Edges

In order to place the hubs in the correct place you should make the Wing and Wheels sketch visible Make the Wing and Wheels sketch visible Click "Project Geometry" button and select the wheels and the line for the bottom of the billet Turn off the Wing and Wheel sketch visibility

If the projected geometry is displayed with solid geometry lines, you may find the sketch easier to view if you convert the lines to construction lines.

Select the wheel geometry Click the "Construction Line" button

Below is my sketch for the Wheel Hubs.

I have created a circle around the axle centre as a construction line. This circle is 6.35mm in diameter, as that is the size of the tool I will use to drill the axle holes.

The Wheel Hub is then a circle around the axle centre, which will leave 5mm of material as the wall thickness after the axle has been drilled. I have done this, as anything under 3mm is liable to break during machining and I have found 5mm of model board all around to be strong enough to support the axles.

I have checked clearance between the Wheel Hub and the Model Base to ensure that my 6.35mm cutter will fit between the 2 extrusions. It is important to keep an eye on this and be aware of the tool that will be used to machine your design from the model board billet.

When you have finished your sketch extrude the Wheel Hubs Be sure to extrude symmetrically.

You should extrude 31mm, as this is the distance we set between opposing wheels in the Wing and Wheels sketch

Axle Holes We are going to use a 6.35mm tool to drill the axle holes in our model.

Create a sketch on the face of the Wheel Hub Draw a 6.35mm circle which is concentric to the wheel hub

Extrude a hole all the way through the body

CO2 Chamber We will now add the CO2 Chamber to our model.

This will be simple to achieve, as we already have a sketch for this.

Turn on visibility of the CO2 Chamber Sketch Extrude the CO2 Chamber 60mm

Select the end of the CO2 chamber and create a sketch Use the "Project Geometry" button to select the cartridge hole Use an extruded cut to make a hole 60mm deep

Your cartridge chamber is almost complete.

It just needs closing at the front.

Closing the Cartridge Hole To close the Cartridge Hole we will create a profile on the XZ Plane and draw a profile which we will use for a revolved extrusion.

Create a sketch on the XZ Plane Use the "Project Geometry" button to select the front, rear, and top of the CO2 Chamber Draw a horizontal centre line through the CO2 Chamber and extending beyond it Complete your profile as I have done in the image below.

Use the "Revolve" button to create a revolved extrusion.

Rear Wing Mount We are going to 3D Print the front and rear wings, but we must first create the mounts onto which they will sit.

For the rear wing mount we want to create a boss on the top of the CO2 Chamber. To do this we must first create a work­plane onto which we can draw the sketch.

Click the bottom of the "Plane" button to open the drop down menu.

Select the "Tangent to Surface and Parallel to Plane" option Select the top of the CO2 Chamber and the XY Plane Your new work­plane should look like the image below

Create a sketch using the new work­plane Make the Wing and Wheels Above sketch visible Use "Project Geometry" button to select the wing geometry Draw a square as per the image below Extrude the sketch 4mm symmetrically to create a boss for the rear wing

Front Wing Mount / Tail­stock We now need to create a mount for the front wing. This mount will also double as the tail­ stock for machining the car.

Create a sketch on the XZ Plane Turn on visibility for the Vertical Reference Plane sketch Draw a rectangle as shown in the image below and trim it so it fits around the Wheel Hub

Extrude the sketch symmetrically 20mm

Filleting We have almost completed the body of our car design. The only thing we need to do now is add fillets to the points where our extrusions meet.

As we are using a 6.35mm tool to machine the car design, our fillets should be 3.175mm or greater.

We cannot achieve fillets smaller than 3.175mm, as this is the radius of the cutting tool.

Add 3.175mm fillets to all edges where extrusions meet

Tether Line Slot Regulation 6.1 states that the tether line slot is optional and free in length and location.

As we have designed this car to be modelled from the Official F1 Model Block, we should add it to our model.

Create a new sketch on the bottom face of your model Draw a 6mm wide slot running the length of your model

Make the 6mm slot an extruded cut 6mm deep.

Drilling Axle Holes It is best to get the CNC Router to drill your axle holes. For this you will need to know the location of them in relation to the datum point.

The datum is at the cartridge hole end of the billet and right in the centre of the cartridge hole, when viewed from the end.

Create a sketch on the XZ Plane and find the distance to your axle holes from the datum

For the model we have created the centre line of the axles is 18.5mm down from the datum.

This is Y­18.5 in a CNC program.

The rear axle is 25mm from the end of the billet. This is X25 in a CNC program.

The front axle is 167.5mm from the end of the billet. This is X167.5 in a CNC program.

Record your values below

Create New Assembly We now need to model the wheels, wings and axle bushes.

If you load the body of your car into a new assembly, then you can create parts in place using the geometry of your car body as a guide when creating new parts.

Select "New" then "New" Select "Standard(mm).ipt" button

Click the "Create" button

Place Part We want to place our car body into our new assembly so that we can create the other parts we need.

Click the "Place" button Select your car body model Click the "Open" button Click to place your model Press ESC to stop placing

Create Part in Place The first part we will create is the axle bush. We will need 4 of these and they will be 3D Printed.

Click the "Create" button The "Create In­Place Component" dialogue box will pop up Enter the New Component Name

Click the "Browse Templates" button The "Open Templates" dialogue box will appear.

Click on the "Metric" tab Click the "Standard(mm).ipt" button Click the "OK" button Click the next "OK" button

We have to select the sketch plane for the base of the feature.

As we are creating a bush for the axle holes, we want to select the Wheel Hub. Select the Wheel Hub You are now back in Inventor part modelling, but the geometry from the body of your car can be used in the creation of your part.

Axle Bush We are ready to create our Axle Bush part in place. Let's begin: Create a sketch on the XY Plane Click the "Project Geometry" button Select the face of the Wheel Hub

Finish the sketch Extrude the sketch 2mm away from the Wheel Hub Now that we have created the base of our bush, we need another extrusion to go into the Axle Hole of our model.

Create a new sketch on the face of the extrusion you just created Click "Project Geometry" to select the inside of the previous extrusion.

Draw a circle concentric to the Axle Hole that is 3.3mm in diameter Extrude the sketch 7mm into the model Click "Return" You have successfully created a part in place.

Save the Assembly

Pattern and Mirror We do not want to create another 3 Axle Bushes, so it would be much easier to use the Pattern and Mirror tools.

Pattern Click the "Pattern" button The "Pattern Component" dialogue box will appear.

In the Model Browser, click on the Bush Click the "Rectangular" button Click the "Column Direction" button Set the direction to be in X as per the image below

Set the number of Elements to be 2 Set the distance to be the distance between your axles Remember we asked you to record this value on page 28.

You can type this as: Front X Value ­ Rear X Value

Click the "OK" button

Mirror Click the "Mirror" button The "Mirror Component" dialogue box will appear.

In the Model Browser, click on Component Pattern 1:1 Click on the "Mirror Plane" button In the Model Browser, expand the model for the body of your car and then expand the Origin.

Select the XZ Plane Click the "Next" button Click the "OK" button

Hopefully, you now have the hang of the Pattern and Mirror tools.

You will be needing them after you have created the Wheel part.

Wheels We will create the Wheel in much the same way as we created the Axle Bush.

Create a new part named Wheel and use the face of the rear wheel bush as the sketch plane Create a new sketch on the face of the rear wheel bush Turn on the visibility of the Wing and Wheels sketch in the Model Browser

Use "Project Geometry" button to select the rear wheel geometry.

Turn off visibility for the "Wing and Wheels" sketch Draw a circle which is concentric to the wheel geometry and make it 3.1mm in diameter Exit the sketch and extrude the wheel away from the body by 16mm.

As you can see in the image below, we now have a solid wheel.

Whilst a solid wheel will meet the regulations it is unlikely to be the fastest. It may be a good idea to remove some material.

How strong you make your wheels is up to you, but regulation T3.8 (­6 pts) states that only 3 sets of replacement wheels are allowed.

With the UP 3D Printers, the minimum wall thickness you should design into your parts is 1mm.

Below this some features may not print.

Remove some material to make your wheels lighter

Click "Return" button to return to the Assembly Pattern and Mirror the wheels, as we did with the Axle Bushes

Rear Wing Now we will design our Rear Wing. This part is to be 3D Printed and as such will be created as a separate component.

Create a part in place as you have done with the Axle Bush and the Wheel Name the part Rear Wing and use the face of the rear wing boss as the sketch plane Create a new sketch on the face of the Rear Wing Mount Turn on visibility of the Wing and Wheels Above sketch in the Model Browser

Use "Project Geometry" button to select rear wing geometry Turn off visibility for the "Wing and Wheels Above" sketch Use "Project Geometry" button to select the geometry of the Rear Wing Mount and the base of the fillets in the model of your main body Draw a rectangle that uses the outer edge of the Rear Wing Mount fillets for its location.

Exit the sketch and extrude the profile symmetrically 8mm Create a new sketch on the rear face of the extrusion

Use "Project Geometry" button to select the CO2 chamber

Finish sketch and do an extruded cut through the extrusion Create a new sketch on the XY Plane of the Rear Wing

Use "Project Geometry" button to select the top face of the Rear Wing Mount on the model of your Main Body

You may have to adjust the Visual Style in order to see the Rear Wing Mount as it is under the extrusion for the Rear Wing

Exit the sketch and extrude the profile down through all.

The mount for your Rear Wing is nearly complete.

Don’t forget to add the 3.175mm fillets to the cut­out so it fits onto your Main Body.

Create a new sketch on the right hand face of the Rear Wing extrusion that you have created Turn on visibility of the "Wing and Wheels" sketch Use "Project Geometry" button to select the Rear Wing geometry Turn off visibility of the "Wing and Wheels" sketch As you can see in the image on the left, the rear wing geometry from our "Wing and Wheels" sketch is much lower than the Rear Wing extrusion that we have created.

This is not a problem, as we drew the rear wing geometry at the minimum height allowed in the regulations. Just draw your new profile higher.

When deciding the height of your wing you should note that Regulation T10.3 (­6 pts) states that there should be a minimum of 3mm clear air space to any other part of the car. We will give ours 4mm clear air space as a safety margin.

Exit the sketch and extrude the profile 21mm away from the car body

Mirror the profile around the XZ Plane

The rear wing now meets the regulations, as it has 2 spans ­ each 21mm wide ­ and the wing surface has 4mm of clear air space around it.

It would look better, though, if the wing surface continued from one span to the other.

Create a new sketch on one of the inner faces of the wing span Use "Project Geometry" button to select the geometry of that face

Exit sketch and extrude it to the other face Your rear Wing is now complete.

Click the "Return" button to return to the assembly

Front Wing We will now design our Front Wing. This part is to be 3D Printed and as such will be created as a separate component.

Create a part in place as you have done with previous parts.

Name the part Front Wing and use the top face of the Front Wing Mount as the sketch plane.

Create a new sketch on the XZ Plane Turn on visibility of the Wing and Wheels sketch in the Model Browser

Use "Project Geometry" button to select front wing geometry Turn off visibility for the "Wing and Wheels" sketch Use "Project Geometry" button to select geometry of the Front Wing Mount in the model of your main body

Draw a curved profile that starts 1mm back from the front of your model and ends 1mm in front of the Front Wheel Centre Line.

The profile should extend from the base of your model at the point 1mm back from the front to 15mm above the base at the point 1mm in front of the Front Wheel Centre Line.

Revolve the profile

Create a new sketch on the XZ Plane to remove all of the revolved extrusion below the base of the car Exit the sketch and do an extruded cut to remove the revolved extrusion below the car

Create another sketch on the XZ Plane Use "Project Geometry" button to select the Wheel Hub in the model of your main body Exit the sketch and make an extruded cut symetrically through all

Create a new sketch on the rear face of the front wing Use "Project Geometry" button to select the geometry of the Front Wing mount on the Main Body.

Exit sketch and extruded cut the profile towards the front of the car by 15mm As you can see in the image to the left, the Front Wing Mount / Tail­stock sticks out from the end of the Front Wing.

This is deliberate, to assist in machining the Main Body of the car.

After machining, the Tail­ stock can easily be shortened in order for the Front Wing to fit.

To make your renderings look better, you can shorten the Tail­stock in your model after you have exported the STL files for machining.

Now that the we have designed the base of our Front Wing, it is time to design the Front Wing surface.

Create a new sketch on the XZ Plane Turn on visibility for the "Wing and Wheels" sketch Use "Project Geometry" button to select the Front Wing geometry Turn off visibility for the "Wing and Wheels sketch Create a profile for the Front Wing like the one below

Exit the sketch and extrude the profile symmetrically You need to extrude the profile far enough so that you have 2 spans at least 20mm in length. In the case of this model, the extrusion was 65mm, giving 2 spans of just over 21mm each.

Don't forget to add 3.175mm fillets to the faces that mate with the Main Body

The last thing we need to add to the Front Wing is the Tether Line Slot As we have used the Official F1 Model Block this is a 6mm x 6mm slot.

Create a new sketch on the YZ Plane and draw a 6mm x 6mm square Use the profile to create an extruded cut through all to get the Tether Line Slot Click "Return" button to get back to the Assembly

Tether Line Guides For this design we will use the 1" Screw Eyes available from Denford Ltd as they comply with the regulations and are designed to fit in the Tether Line Slot in the base of the billet we are using.

Critical Regulation T7.1 (­6 pts) states that the car must have 2 guides, one in front of the Front Axle and one behind the Rear Axle.

Regulation T7.3 (­2 pts) states that the minimum distance between the inside edges of the guides is 120mm.

As you can see below, a sketch has been created on the base of the car to check that the Tether Line Guides can be fitted to our design within the regulation.

Check you can fit Tether Line Guides to your design.

Exporting STL's Having created all of the parts for our car we need to manufacture them.

The software we use for manufacturing parts accepts STL files. We need to export our design from Autodesk Inventor as STL's Click the "Inventor" button Scroll down to "Export" Move across to "CAD Format" and click the left mouse button

When the "Save As" dialogue pops up, change "Save as type" to STL Files Click the "Options" button

It is very important to set these settings correctly. If these settings are incorrect, your design will not machine correctly.

Units are set to CM by default, as the machines we are using to manufacture these parts use mm. It is important to change this setting to prevent your part being scaled incorrectly.

Set units to mm Resolution is set to Medium by default. This affect the quality of curved surfaces mainly. If set too low then wheels will be printed as polygons, rather than circles and we do not want this.

Set resolution to High Click "OK" button Select a folder to save your STL's to and click "Save"

Axles We are going to use the Long Axles for this model. These are available from Denford Ltd. The axles are 65mm long and 3.2mm in diameter, made of steel and they weigh 4g.

Create a part in place as you have done with previous parts.

Name the part Long Axle and use the right hand side face of the Front Wing as the sketch plane.

Create a new sketch on the XY Plane Use "Project Geometry" button to select the Rear Wheel geometry

Draw a circle concentric to the Rear Wheel which is 3.2mm in diameter

Exit the sketch and extrude the profile 65mm Click "Return" to go back to assembly mode Pattern the Long Axle just as you have previously done with the Axle Bushes and Wheels

Calculating Weight of Model Before manufacturing our car, we may want to know the weight of it.

The density of the Official F1 Model Block is 0.16g/cm3 For the Wings, Wheels and Axle Bushes, the density of the filament is roughly 1g/cm3 The Long Axles are made of steel and have a density of 7.850g/cm3 We can enter this density into Autodesk Inventor to find the weight of our billet when machined.

Adding New Material The Axles are made of steel and the "Steel, High Strength, Low Alloy" material in the Autodesk material library has the correct density.

We will need to add materials for the Official F1 Model Block and the 3D Printer Material Select the "Material" button (Above the Sketch tab) The Material Browser will appear as illustrated in the image on the right.

The Material Browser should have "Generic" listed under "Document Material". We need to create 2 new materials.

Click the "Create New Material" button

The Material Editor will appear, as illustrated on the right.

The Material Editor has 3 tabs: Identity, Appearance, and Physical.

The Identity tab will be selected first.

Enter all details as shown on the right and click the "Apply" button Select the Appearance tab

The Material Editor will change to show the options illustrated on the left.

For the Official F1 Model Block, set the colour to a shade of green and turn off Reflectivity and Transparency Click the "Apply" button When you create the 3D Print material you may wish to adjust the transparency and reflectivity, depending on the material you are using.

Finally the Physical tab. We want to enter the density here, so that Inventor will be able to calculate the weight of our model.

Select the Physical tab We are only interested in the Mechanical section here.

Expand the Mechanical section Enter the density for the Official F1 Model Block as 0.16g / cm3 When you type the density in and hit enter it will revert back to pound per cubic inch, don't worry about this.

Click the "Apply" button Click the "Close" button to exit The Material Browser will now show the Official F1 Model Board in the Document Materials To add this material to the Autodesk Inventor Material Library follow the instructions below: Right click on the material Select > Add to > Inventor Material Library > Plastic You have now added the Official F1 Model Block to the Material Library.

Repeat the process to add your 3D print material to the Material Library Most filament has a density of roughly 1g / cm3.

Adding Material Properties To add material properties to a part, follow the instructions below: In the Model Browser, right click on the part and select "Edit" Right click on the part in the Model Browser again and select "iProperties"

Select the "Physical" tab Select the Material Click "Apply" Now add material properties to all parts in your assembly After you have set material properties for all of your parts you can check the weight of your assembly.

Right click on the assembly in the Model Browser (Top of the parts tree) Select "iProperties" Select the "Physical" tab Click the "Update" button The Mass of your model will be displayed under the General Properties section.

Adding Decals To make the renderings of your model look more realistic for your portfolio, you may want to add decals for your sponsors.

To do this, you first need an image to be used as your decal and it is recommended that you save these in the same folder as your model.

Decals are placed by first creating a sketch and loading the image for your decal into the sketch.

Positioning and resizing are all done in the sketch.

After exiting the sketch, the "Decal" button is used to project the image onto the surface.

For curved surfaces, create a work­plane above the surface to project the decal onto.

We will place a decal onto the rear wing. You must have the part open, rather than the assembly for decals.

Open the "Rear Wing" part Create a sketch on the rear wing Click the "Insert Image" button Select the image you wish to use Rotate and resize the image to fit the rear wing Exit the sketch Click the "Decal" button Select the sketch to be used as a decal Select the face you wish to place the decal onto Click the "OK" button You can now apply decals to the rest of your model.

Drilling Axle Holes CNC Program To drill the axle holes, it is best to use the Denford CNC Router, whilst the billet is still in the fixture after machining the right or left sides.

As the Official F1 Model Block is quite low in density it can be drilled using the 1/4" (6.35mm) Long Reach Ball Nose cutter which is used for machining the body of your car.

Type the code below into a new text document and save it as "Axle Holes.fnc" The values in red should be substituted for the values you recorded on page 28