00:00 |
The final feature's remaining to finish the subframe of the steering rack mounts.
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00:04 |
Earlier, when creating the main structure of the subframe, we actually created one of these for the top of the car section on the driver's side through the bushing.
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00:14 |
But we still need to create the other one of these and also a clamp on the other end of the steering rack, which in the factory subframe is achieved with a pressed steel part and a factory rubber bushing.
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00:26 |
Our method won't be too different.
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00:28 |
We'll be using a billet mounting block that was actually designed for use with a blade style adjustable anti roll bar.
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00:35 |
But will be the correct size to clamp the steering rack in the larger diameter factory location along with a polyurethane bushing.
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00:43 |
First though, let's create the remaining mount on the car section on the driver's side.
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00:48 |
This mount will be made from sheet metal and create a web structure between the tubes of the subframe.
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00:54 |
To start, we'll sketch on the plane we created earlier on the top of the bushing mount on the steering rack, placing a circle for an M10 bolt aligned with the mounting hole.
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01:05 |
Then we can sketch a profile around this for the bottom plate, which will be 60mm wide, centred about the mounting hole.
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01:13 |
The front and back edges need to run parallel and as close as possible to the tubing so they can be welded together.
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01:21 |
Using the intersect tool can help with this, but we'll still want to offset the line to give some amount of clearance.
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01:28 |
The sides of this can also be offset back 3 mm and then we can incorporate tabs into the side , which we'll locate in slots in the side plates that we create next.
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01:39 |
Making these different on each side means it can be only assembled in one orientation to make things easier when it comes to the manufacturing stage.
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01:48 |
With this sketch complete we'll use the flange tool to create the sheet metal body and as always check the direction preference is correct.
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01:57 |
Following these we can sketch on one side of the base plate inside the tabs.
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02:01 |
We'll project the edges of the base plate including the tabs, sketching around these for some clearance slots.
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02:09 |
And also use the intersect function to create the profile where the sketch plane intersects the tube.
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02:16 |
Then draw a line across tangent to the bottom side of both tubes, adding some tabs along this line as well and finishing with some small 2mm arcs to round the four sharp corners of the part.
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02:38 |
Then it's just a matter of using the flange tool to create the 3D body and copying the same method for the other side.
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02:45 |
We'll then make a cap to brace the structure and cover in the bottom area.
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02:49 |
But before this we'll use the plane through three point still and select points on the edge of each side plate so the next part can sit flush with each side plate.
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02:59 |
We'll sketch on this plane, projecting the edges from each side plate and creating clearance slots for the tabs.
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03:05 |
We'll also draw lines between each side that run along the tube structure and can be welded to the tube.
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03:17 |
In the centre we'll create a slot that extends over the centre of the mounting hole in the base plate so there'll be plenty of clearance for tools and hardware.
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03:27 |
Finally, using the flange tool to create the last sheet metal part for this mount and checking our work to make sure everything should work as intended.
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03:36 |
Moving onto the clamp mount on the passenger side, I have a model of the billet clamp part that we'll use.
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03:41 |
So, let's find that in the data panel, right click and insert it into the current design.
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03:46 |
This is a simple extruded part with a hole in the middle for the steering rack and bushing as well as the bolt holes.
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03:54 |
We'll align the hole with the steering rack first and then use the move tool, setting the pivot point to the centre of the clamping hole.
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04:02 |
This way we can drag it into a suitable position on the section of the steering rack with the larger diameter and also rotate it into an orientation that will allow it to be assembled without interference with the other parts of the subframe and also provide access for the hardware and tools.
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04:21 |
Once we're happy with the location, it's just a matter of building a sheet metal structure that will support the mount and will be stiff enough to prevent excessive compliance.
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04:30 |
To start we'll sketch on the bottom surface of the billet clamp, projecting the edges and the holes and also using the rectangle tool for a slot in each corner.
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04:52 |
After making this part with the flange tool, we'll need to make a base part that spans the space between the tubular structure.
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04:59 |
Using the plane through three point tool, we can select the points at the ends of each notch on the bottom of the diagonal tubing from the rear member to the lower control arm mount.
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05:11 |
Now, we have a plane essentially tangent to the tubing so we can make the base flange to brace it all together.
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05:18 |
So, we'll sketch on this plane and first sketch a line from the point on the notch near the lower control arm point to the point on the notch on the rear member for each tube.
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05:29 |
We'll also project the most rearward edge of the sheet metal base for the billet clamp and then sketch an arc with a large 300 mm radius between each tube centreline that passes through the driver's side end of the projected line for the billet clamp.
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05:45 |
After making the ends of the arc horizontal with each other, to fully define the sketch, we'll use the fillet tool to radius the external corners and then fix any definition issue using the coincident constraint between the tube's centrelines and the notch points.
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06:02 |
Finally, we'll just make two slots in line with those on the clamp base plate for some self jigging of our next parts.
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06:09 |
At this point it's just a matter of connecting the two base flanges with some vertical pieces.
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06:15 |
So, for this we can sketch on the side the sheet metal base for the billet clamp and then use the project and intersect tool to create the profile at the intersection of the sketch plane and the lower base flange and the diagonal tube.
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06:29 |
Then we just need to connect the tube and base flanges with straight lines including tabs for slots where necessary as well and then use the flange tool and then check for clearance and alignment.
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06:53 |
That completes the modelling process for the subframe with the mounting points, tubular structure, lower control arm and caster mounting points and steering rack mounts.
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07:03 |
The subframe clears the drivetrain and should provide a stiff and strong structure, while also relocating the caster arms behind the axle to avoid damage in minor collisions.
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