00:00 |
- With a clear idea of what we're trying to achieve in mind, let's get started on the practical work by taking down some measurements that we can use to check and calibrate the size of our canvases in 3D scans.
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00:11 |
Ideally these will be key dimensions realted to the valve cover's mounting locations onto the cylinder head.
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00:18 |
If you're designing for your own application, you'll of course need to tailor the design to suit your specific cylinder head and constraints.
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00:26 |
The first step was measuring the distance between the mounting holes at the front corners of the valve cover.
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00:31 |
The spacing of the spark plug holes, the spacing of the holes along the driver size of our right hand drive car and the spacing between the driver's and passenger's side.
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00:41 |
As well as the thickness of the current flange and the mounting holes and hardware size.
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00:47 |
Although we only really need one or two of these measurements to get our scans and canvases to the correct scale, it's worth taking down as many important measurements as possible to check against our model and make sure that it's accurate.
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01:00 |
To use 3D scans and canvases as references for our design process, we would ideally have a few variations of assembly.
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01:09 |
Without access to a high resolution and high accuracy 3D scanner, a 2D image or canvas of the flange of the cylinder head or the current valve cover will be the most accurate method of using the interface as a reference for the CAD model.
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01:23 |
There are a few ways of getting this image, obviously we need to have the valve cover removed, then we can carefully use a flatbed scanner to scan the flange of the valve cover if the scanner is big enough.
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01:35 |
Or take a photo directly at the surface from a distance with a long focal length to minimise distortion.
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01:42 |
Alternatively we can take a sheet of card, fix it to the flange using the mounting holes and use a hammer to lightly form an imprint of the flange into the card.
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01:51 |
In our case, we can't remove the current valve cover due to time constraints before an event but we do have another spare cylinder head with the valve train removed that we can use to make an imprint on some card.
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02:04 |
Since we're using a small A4 flatbed scanner, we need to take multiple scans and then stitch them together in another program like photoshop but ideally you'd be able to take the entire scan at once to avoid errors.
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02:18 |
With the image file on our computer, ideally as a PNG, we can insert it as a canvas onto our top plane and then rotate the canvas so it's like we're looking at the valve cover from the front of the car.
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02:30 |
Making sure the left and right hand side of the valve cover match that of the driver's and passenger side of the vehicle so the canvas isn't flipped upside down.
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02:39 |
We also need to calibrate the canvas with the use of our physical measurements.
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02:44 |
As always it's best that these are relatively large compared to the canvas size and it's good to check another dimension in a different direction to make sure the canvas is true to the correct shape and proportions.
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02:58 |
From here we can right click and edit the canvas feature in the timeline again.
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03:03 |
We want to try to get the bottom left and right corner holes of the flange in line horizontally and this will help us when it comes to creating our sketch for the new valve cover flange.
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03:14 |
Using a sketch of a horizontal line on the same plane can help with this.
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03:18 |
It's best to align the mounting hole in the centre of the cylinder head with the origin and this will help us when it comes time to align our 3D scans with the canvas.
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03:28 |
In terms of 3D scans we ideally need one with the current valve cover fitted to the vehicle so we can understand the geometry of the original design and try to fit inside this envelope to avoid clearance issues with the inside of the bonnet or hood or other parts.
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03:43 |
Another 3D scan of the engine bay without the valve cover on will give us two advantages.
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03:48 |
Being able to make sure we have clearance to the valve train and also we'll be able to get a picture of what our new design looks like in the engine bay.
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03:56 |
Again in our case, we can't remove the current valve cover at this time but luckily we have a third cylinder head with the valve train still assembled that we can scan separately and then align this with our cylinder head from the scan in the engine bay.
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04:11 |
My personal phone is an iPhone 11 so that's what I'm using along with the Trnio app to take these scans.
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04:18 |
Since Trnio is only avaiable for Apple iOS, I'd recommend trying the WIDAR app for Android users but there are plenty of good options out there for all mobile operating systems.
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04:30 |
Inside the Trnio app, we select the ARKit setting for our scan, hit the record button and slowly and smoothly move the phone, gathering data from the engine bay, covering all the important aspects from as many angles as possible.
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04:44 |
Once we're happy with the scan or reached the maximum limit, we can hit the record button again and click yes to create the scan.
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04:51 |
The scan will then upload and generate which can take up to an hour for a scan of this size, depending on your phone and internet connection.
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05:00 |
After the scan has been created, it's worth checking over it to make sure you have all the data you need in case you need to retake it.
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05:08 |
From here, you can click and hold on the scan, choose to export the scan and send it to your computer using any of the usual methods, either as an STL or OBJ file works fine but using the OBJ option, we'll be able to retain the texture and colours from the scan.
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05:24 |
With the scans on our computer, the next step is to bring them into Fusion 360, scale them to the correct size and align them with our canvas.
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05:32 |
For this, we'll actually use a new design so the scan is its own external component.
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05:37 |
This helps us easily align the scans in the main design file which will make more sense in a moment.
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05:43 |
Moving to the mesh toolbar, we can select the insert mesh function and then locate the mesh file on our computer.
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05:50 |
Although it doesn't particularly matter for 3D scans from a smartphone or at least iPhones using Trnio, select metre for the unit then we can rotate the scan to reorientate it into roughly the right position and then click the centre button.
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06:05 |
This is the time to scale the mesh to the correct size, we can use the measure tool and compare this to our physical measurements to find the scale.
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06:13 |
After using the scale mesh tool we can then recheck with the measure tool to make sure we've got it right.
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06:20 |
Next we want to make a plane that aligns with the flange surface, the easiest way to do this is actually by selecting create form to enter the forms toolbar and then using our plane through 3 points tool from here.
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06:32 |
If we carefully click 3 well separated points along the flange on the top of the head where the valve cover mounts or in our case at the interface between the parts, we'll get a flat plane on this surface.
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06:45 |
Then we can save the file and close it and with our main design file open, right click the scan component in our data panel and insert it into our current file with the canvas.
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06:57 |
With the mesh in our workspace at the correct scale, we can select the align tool under the modify tab, changing the object preference to component, then selecting the construction plane from the mesh component and the top plane that our canvas is applied to.
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07:12 |
From here we can use the move tool to move the mesh component, first by clicking the set pivot button and choosing a point on the construction plane and clicking the tick to confirm.
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07:23 |
Allowing us to drag the mesh in centre on the mounting hole in the middle of the head above the flange.
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07:29 |
Rotating the mesh around the vertical axis without losing alignment of the planes we just set.
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07:36 |
The placement of these scans down to the exact millimetre is not too critical as they're just for a visual reference and the canvas will be used for the accurate dimensions.
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07:46 |
From here it's the same idea with the other scan, scaling it to the correct size and creating a plane on the flange surface then inserting it into the assembly design file aligning the planes and positioning it in place.
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07:59 |
Once we're happy with how the scans are positioned, it's best to ground the components so they can't be moved accidentally.
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08:05 |
In our case we had to copy the mesh bodies of the engine bay and delete the valve cover section from one of these meshes using the plane cut tool but this wouldn't be required if both scans were in the engine bay with the current valve cover on and off.
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08:22 |
To summarise, we now have a range of measurements, a canvas and 3D scans which have been set up in CAD to use as references as we move onto the next step of modelling our design.
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08:34 |
At this point it could also be worth doing some brain storming, maybe sketching something on paper or researching valve covers online to get an idea of what we want the final product to look like as this will guide the steps when it comes to modelling the design.
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