Week 10 - Challenge 2- Attachment Feature Creation (Dog House)
1.OBJECTIVE: To create the Door Trim Plastic Component from the given Class A Surface & then create two dog houses as attachment features for it while following the given Design Guidelines.
First, we will begin by checking the State of Connectivity for the Class A Surface and ensure that there are no gaps between the surfaces as all the surfaces should be joined well together with each other and shouldn't consist of any discontinuities between them.First, we'll click on 'Join Command' and select our Class A Surface. Then, we have to ensure that the 'Check Connexity' option is marked as shown in the images below. It will check for any gaps that may be present between our surfaces. Then, we'll click on the 'Preview' button and if it doesn't show any 'Connexity Error' on our surface then it means our surface is well-connected and there are no discontinuities between it.
We'll view the Class A Surface from different axes to find out the optimal axis along which we can create our Tooling Axis.Since the direction is the most important factor while creating the Main Tooling Axis, we'll just pick any vertex at the extremity of the Class A Surface or Use the Inertia Method to find out the Center of Gravity and use that point to create a line along the required direction for the Main Tooling Axis. We have to perform a draft analysis on the Class A Surface to crosscheck if feasible to be the Main Tooling Axis or not.
Now, We will perform a Draft Analysis on the Class A Surface itself using the Main Tooling Axis created.Before starting with a Draft Analysis Operation, we will go to the 'Customize View Parameters' option under the 'View Toolbar'. Then we will enter the 'Customize View Mode' where we will go under the 'Mesh' option and select 'Material' and press 'OK'. To start the Draft Analysis in the 'Generative Surface Design Workbench', we will go to 'Insert' and then look for the option called 'Analysis'. Once found, we will go under that and click on 'Feature Draft Analysis. This will open the 'Draft Analysis' Dialogue box. There, we will ensure that under 'Mode' we have selected 'Quick Analysis', under 'Display' we will select 'Show or Hide the Color Scale' and then select '3 Degrees' as the permissible draft angle. Then, under 'Direction' we will choose the icon with the symbol of the compass on it which stands for 'Use the Compass to define the new current draft direction'.
inorder to create class B surface,We'll start the procedure by creating an offset for the entire Class A Surface at a distance of 2.5mm as that is the desired thickness for our final plastic component.As this is a complex surface hence the offset will fail to offset every element according to our necessity. It'll select some sub-elements that belong to the filleted regions by themselves that we have to remove to get the rest of the surface that is offset.
We'll create the Class C Surface with respect to the Class A Surface and provide draft angles to those surfaces that are parallel to the Main Tooling Axis. Surfaces at the bottom won't be needing any draft angle as they'll get cleared by the core itself. To create the Class C Surface we have to use various commands such as Sweep with Reference Surface and With Draft-Direction depending upon the necessity and at places where it'll be difficult for us to create a surface using Sweep, we'll use Multi-Sections Surface to create those surfaces. The draft angle will be 3 degrees.
Then, we'll create an intersection with the Class B Surface and check if it is feasible to trim with each other. After inspecting the intersection, we noticed that the Class B Surface was not intersecting with the Joined surface of Class A & C and hence we extrapolated the Class B Surface as shown below.After this we trimmed the extrapolated Class B Surface with the joined surface of Class A & C.
Finally, we'll go to the Part Workbench and use the option 'Closed Surface' from the 'Surface-based Features' toolbar to convert the final trimmed body into a solid body.
PROCEDURE TO CREATE THE DOGHOUSE:
From the sketch, we can see that the width of the doghouse is more than 12mm which is one of the design rules. We cannot go below that value.Then, we'll use the Sweep Command with the Draft Direction to provide a draft angle of 3 degrees with respect to the Main Tooling Axis.we can see that 1.5 degrees draft angle is provided to the sweep surface.After this, we're going to use the Multi-Sections Surface command to create the top face of the doghouse as shown below and join it with the sweep surface.Now we're going to move on to the Part Workbench and use the Thick Surface command from the Surface-based Features toolbar to thicken the surfaces by 2mm.Then we're going to provide a draft angle of 1.5 degrees to all the adjacent faces as shown below using the Draft Command in the Part Workbench.After this, we're going to remove the material from the lower section of the doghouse for coring and to do that we going to use create a base surface of the doghouse using the Multi-Section Surface command and then offset it by 4mm. Then, we used the Multi-extract command to extract the inner faces of the doghouse and trim it as shown below.Now, according to the design rule, the thickness of the coring section's wall should be 40% value of our part's thickness and 40% of 2.5 is 1mm and our current wall thickness of the doghouse is 1.685mm. Hence, we're going to offset this trimmed surface by 0.685mm and extrapolate it so that we can use the Split Command from the Park Workbench to remove material from the doghouse.After that, we'll provide a draft angle of 1.5 degrees to the newly formed surface made using the coring operation.Finally, we're going to provide all the necessary edge fillets on the required surfaces following the design rules.Hence, our doghouse is finally complete and we'll make the second house following the same design rules.Now, we'll perform a draft analysis operation on our doghouse to make sure that is clearing along the required tooling axes.