Parametric Families

Parametric Families

Baluster Panel Family: This parametric family incorporates a baluster panel made of glass or metal panel with steel or aluminum cleats. Two options are designed: 1. a plain glass and cleat baluster with no vertical member/s 2. A baluster panel with vertical members.

Purpose: To enable parameterize not only number of glass panels and cleats that fix glass panels but also glass width changing with a gap between them. This ensures that gap between two consequent baluster panel is not more than a certain value, as wider gap may not be safe.

Modeling Process: As described in the figure, this family is an example of nested family. A cleat family is nested into a glass panel family that is nested into a baluster panel family. Parameters relating to aligned and angular dimensions and materials are passed from the first family through nested families to the final baluster family. It was interesting to know that host family governs not only host family parameters but also, the nested family parameters. Following sketches show the equations used and respective processes. Modeling process involves creating families and nesting them to create main family. Following families are created: 1. Cleat family; 2. Glass panel family, 3. Double rail family. All parameters that are related to family’s structure and behavior are transferred from nested family to host family

Create cleat family using extrusion and constraint their top and bottom slopes to suit to the slope of top and bottom rails of baluster panel. Create behavior and material parameters and relate them to desired materials by editing type properties. Create a glass panel family by extruding a rectangular plane constrained by top and bottom slanting reference planes

Load cleat family into the glass panel family and transfer its parameters to the host family. Two side vertical baluster members could be created by increasing height of cleat family type. Create an array of cleat family to make cleat members as shown in figure.

Now we can use this glass panel family and modify its size, angle and materials also. We finally create a double rail family that acts as main host family with top and bottom sloping rails. These rails possess slope and height parameters that could be modified. 

Glass panel family is loaded inside this main family and it is constrained at two ends by creating two vertical planes. Its changing vertical distance H1 is parameterized with equation: ((Rail Length / 2) - 0'  0 1/4") * tan(Rail Slope Angle) where ¼ inch is the distance of right hand side vertical reference plane. Glass panel family is also aligned and constrained with these vertical planes. Parameters of glass panel family are transferred to the host family by editing type properties. Now parameters of the main host family (double rail) can be modified to control parameters of the nested families.

Some of the challenges included keeping the gaps between the glass panels exactly 3 inches. For this exact gap remaining after filling up panels is calculated. This gap is then divided by number of panels (this number is rounded down by subtracting 0.49) to get a number that needs to be adjusted in each glass panel width. Following figure describes these equations. 

Remaining Challenges


One of the aspects that need work is trying to keep the gap between the glass panels exactly 3 inches so that whenever the array is performed the gap between two array elements is always 3 inches. Furthermore, user should also be able to select and modify not only parameters but also, be able to modify and select shape of the components. However, it is possible only with programming skills.