Let’s take a look at the summary for today. First of all, we will be taking a look at Splines and some of its basic terminology and functions. Then, we will be seeing how we can utilize splines to achieve optimal material flow with some examples even before conducting any simulation/flow simulation on our design. The next portion we will be discussing on sketch blocks in mechanical designs with some examples as well.
– 3 points make a spline (the fewer the better)
- With normal spline creations, we just need to input the spline points to create the spline. The lesser the points, the easier it is to manipulate it
– Spline Handles
- These Handles allow users to change the degree and length of the spline freely to obtain the desired shape
– Spline Property Manager
- In the Property Manager for the spline, users can access to multiple functions discussed in this section
– Tangency, horizontal, perpendicular constraints
- Relations can be added to the spline handles to fully define the spline
- Dimensions can also be added to define the spline
- To obtain a symmetric shape of the spline, the mirror function is crucial to ensure smoothness of the transition
- By fixing the spline, we can modify other entities around the spline to get our desired design intent
– Fit Spline
- Fit spline is used to combine 2 separate splines into one
- When proportional is selected in the Spline Property Manager, we can freely change the size of the spline while retaining the overall shape
– Style Splines
- New in SOLIDWORKS 2014, the style spline utilizes construction lines to create the spline for easier manipulation of the spline
– Curvature combs – we see the results as we design!
- Curvature combs allow us to evaluate the acceleration and deceleration (Smoothness) of the spline curve that we have created
Optimal Material Flow Example
Curvature combs can provide a great insight into our design even before we proceed to perform flow simulation on our design. Consider the following hourglasses. One of them is an ordinary hourglass while the other seems to be magical in terms of the flow rate. Tracing the pictures using the spline tool, we can evaluate the curvature comb for both hourglasses.
The curvature comb of the ordinary hourglass shows that the curve decelerates right at the beginning and the ending, causing the flow to decelerate as it approaches the orifice.
The magical hourglass on the other hand, accelerates drastically near the orifice, allowing the sand to flow quickly at the orifice.
Although the overall shapes of both hourglasses are essentially the same, by using the curvature comb display, we can adjust the shape just slightly to amplify the effectiveness of our design.
Sketch Blocks in Mechanical Design
‘Sketch block’ is a function that groups multiple pieces of sketch geometry and dimensions together, allowing users to move it about as if it is a single entity. Utilizing sketch blocks in layout-based assembly design can create in-context parts straight away from the assembly file itself.
One very handy advantage of using sketch blocks is that we can represent the motion of an assembly in a 2D environment first. Sketch blocks can be saved separately as .sldblk files for easy importation.
When creating a new assembly, click ‘Create Layout’ instead of importing part files.
Then, create sketches and save it as blocks.
Sketch Blocks can be created in either layout-based assemblies or in sketches of parts. Importing multiple sketch blocks into the layout and adding in relations between entities allows users to move/rotate individual blocks as if it is a single part. Using that, we can quickly evaluate the accuracy of our sketches before we create the parts for the assembly.
**For detailed hands-on exercises on these examples of splines and sketch blocks, please refer to the video.
By JJ Chan,
Application Engineer, CADVision Systems Sdn. Bhd.