Adjusting the Trim Order of Weldments

SolidWorks users who work with weldments often spend a significant amount of time creating and applying the proper corner treatment to structural members that meet at a common vertex. Applying corner treatment is a fairly straightforward procedure for structural members of the same group, and can be adjusted through the structural member Property Manager. However, when multiple groups meet at the same vertex, a trim order is established, with the second group automatically trimming with respect to the first group, the third group with respect to both the first and second groups, and so on. This trim order can be adjusted to force groups to trim simultaneously, allowing for the creation of complex corner treatments and greater flexibility in designs.

We’re beginning with a relatively simple 3D sketch as shown below. To add structural members, activate the weldments tab and choose Structural Member, specify your weldment profile standard, type, and size, and choose the appropriate sketch segments for each group. In this example, all of the members will use the same weldment profile and size, so only a single structural member feature is required. Groups must consist of sketch segments that are contiguous (touching end to end) or parallel, and were created according to the colored illustration below:

Having created these groups, you’ll find that some default corner treatments are automatically applied. Within Group 1, members are trimmed with a 45° miter. This can be adjusted to an end butt configuration if desired through the Property Manager, but this is the only other option. Group 3 is then trimmed with respect to Group 1, shortening the member as needed in order to fit. This is because of the trim order that has been established, and this order can be changed by editing the Structural Member feature and selecting the vertex where the three members meet.

At this point, a Corner Treatment dialog will appear with the current trim order of all involved groups (two in this case). To force both groups to trim simultaneously, set the trim orders equal. For this specific vertex, it doesn’t matter whether the order is set to 1 or 2, as long as they are consistent; however, this may have impacts downstream when trimming with respect to other groups, so it’s important to be aware of the implications of changing trim order. The result is a three-way miter between the three structural members, which is impossible to achieve without adjusting the trim order.

The concept of setting trim order can be extended to vertices with more than three structural members as well, and this can be accomplished using the same strategy. At the intersection of Groups 2, 3, and 4, the trim order has been set to 1 for all groups, and the result is a four-way miter that is impossible without adjusting trim order.

Adjusting the trim order for weldment structural members is a quick and powerful way to achieve the exact design intent you’re looking for when working with weldment designs, and allows you to create some pretty interesting and aesthetically pleasing corners. Try it out, and let us know what you think. Happy modeling!