Wonders of Weldments

3+ Way Mitres in Weldments

When building steel frames, particularly in circular tube you can strange results when 3 or more tubes come together and you and to trim them all back.  You could end up with something like this:

So how can I make it look like this? 

It's all in the trim order.  Edit the Structural Member feature and click on the joint so you get the Corner Treatment Dialogue box. 

What we are looking for is the Trim Order settings at the bottom.  For each of the groups simply set the Trim order to 1 and they will all mitre together.  It even works for 4 or more segments:

To see this in action you can check out our youtube page.

Creating a profile wrap for cutting

When working with tube in this way it can be tricky to work out how to cut the tube back to the correct finish so that it will fit first time.  What a number of people do is create a flattened version of the tube and print it out so that they can cut out the printed profile and wrap the paper around the tube so that it can be marked for cutting.

Here's how to do it.

First we need to save the bodies out. I could do this in the original part, but I'd prefer to keep these files separate.  You can either save each of the bodies out to individual parts, or you can do as I did here, right-click on the CutList folder and select insert into new part.  Then do a 1 degree cut in the tube:

Ensure that you only cut that one body.

Then use Insert bends from the sheet metal toolbar

Setting the K-Factor to 1 ensures that the outer face of the tube will not change in length when flattened.

Repeat for the other bodies and you are then ready to print the profiles. Simply create the flat patterns for each.  You could also use the export to .dxf to create quick simple profiles for the guys on the shop floor.

So there you have it a couple of tips for working with weldments.