I have seen many users attempt to adjust the scale of the OOTB weld symbol and end up with unexpected results; most often the issue is that leaders display a gap instead of attaching to the geometry directly. I'd like to explain the methodology with an example of scaling this family down 1.5 times while making sure that the leaders work properly. Please keep in mind that this is not for Family Editor beginners. You need a good understanding of Family Editing before being able to follow these steps. I'm going to illustrate a simplified version with 3 symbols and no notes, as it should illustrate the process without making this intolerably long.
You will still have to bear with me though because this is going to be longer than a normal post, but I think is more valuable to have all of the information together than to break it into pieces. I'm going to put in small thumbnails of the images to try to keep the flow of the document manageable; you can click on the images to see them full-size.
Generally one of the best ways to figure out how to model a family is to look at an existing one. So I am going to do a lot of comparing with the existing Weld Symbol.rfa family to make sure we understand what is making it work. One of the most important things to consider before you attempt to create this new family is scale. Scaling down has to be done precisely or it will not work, so it is important that all of the adjustments you make are set to the same scale.
Let's begin by opening our existing family at Annotations > Structural > Weld Symbol.rfa, starting a new Generic Annotation.rfa family, and viewing them side by side in Revit.
In the Weld Symbol, go to Family Types and turn on the visibility of the Tail Note, Weld All Around, and Field symbols. Then go into Visibility/Graphics and turn on Dimensions and Reference Planes. Go ahead and hide the text labels to clear up space since we're not going to deal with them in this example.
In the Weld Symbol family, you'll see that there are various Annotation Symbols loaded into it. In this example I am only going to deal with Weld Symbol-All Around, Weld Symbol-Field, and Weld Symbol-Tail. Edit each of these families and scale them down 1.5 times. So the All Around circle should have a radius of 1/16", the two lines of the Tail should be 1/6", etc. Make sure to get these scales right! Then load them into your new family.
Let's start with the main horizontal and vertical lines. The line lengths in the Weld Symbol family are 1 1/8" horizontally and 1 5/16" vertically, so in our new family they will need to be 3/4" and 7/8" respectively. Note that the horizontal line is of the subcategory Generic Annotations and the vertical is <Invisible Lines>
Leaders in Revit want to attach to the outermost edge of a family. In order to get the leader to attach to the center of the All Around circle, we need to set the origin to move based on the side that the symbol and leader will be on. Make sure the horizontal line is along the horizontal reference plane, and set the vertical line 1/8" to the left of the vertical plane to accommodate for the width of the circle.
Now let's go straight to adding the Tail symbol. Place one on either end of the horizontal line. The following video illustrates the next few alignments that need to be made based on the Tails to add the Origin Position parameter.
Back in the Weld Symbol family, you'll find a 3/32" extension line on either side. Add the corresponding scaled 1/16" ones in our family.
Now let's add the Field and All Around symbols to either end. A tip for adjusting the Field Symbol is to use the snaps at the top to drive the location, not the vertical line (see image below).
Now that the symbols are in place, we'll add some dimensions and constraints. Dimension from the Centerline of the circle to the invisible vertical line. Lock the dimension on the left, and keep the one on the right unlocked.
Constrain the 1/16" extension lines to the centerlines of the circles and lock the constraint.
The family shifts based on whether the symbol is on the left side or right side. We need to start setting some visibility conditions to determine what turns on and off. Here it's helpful to go back into Weld Symbol.rfa and mimic what you see in that family. The following video will show you what I mean. Basically what I'm doing is looking at the visibility parameters of the symbols in the Weld Symbol family and copying the settings in my family.
Now that the visibility parameters are set, we need to define which symbols turn on for each side. A good way to figure out how is to again look at the Weld Symbol family. You can copy the Symbol Right and Origin Position Formulas into your family, and just edit the distances to match your scales, as shown in the following video:
Now let's load our family into a new project and see how we did!