Plastics Design Tools: Mounting Boss
The Mounting Boss feature in Solidworks is a great time saver and a great space saver in the FeatureManager. It creates the boss, a hole and a pattern of ribs all in one feature.
You can find the Mounting Boss in two places: First is of course through the menus, Insert>Fastening Features>Mounting Boss. The second is on the Fastening Features toolbar. By default the Fastening Feature toolbar does not have a CommandManager tab, and the Mounting Boss is not on the regular Features toolbar.
You would think that a CAD program that has tabs for Sheet Metal, Weldments and Mold Tools would have something that mentions the word Plastics, but it doesn’t. But that’s ok, because the software is customizable, right? So you can get a little revenge by making your own CommandManager tab for Plastics Features. Do it. C’mon, do it.
The Mounting Boss asks you to provide three pieces of information to get started: 1) A face that the base of the boss will intersect. 2) An Axis or plane to determine the direction of the boss (optional) 3) A circle sketch or circular edge to place the boss on the base face.
Where you select the base face actually creates a point in a 3D Sketch to place the boss, but you can only edit this after the feature is created, not during creation. This seems like more info than the system should need. It should be able to get by on just the circle sketch, but take it from me, it doesn’t do any good to fight the software.
The next step is to determine what kind of boss you want to create: Hardware boss for screw connection or Pin boss, for press pin.
The boss height can be determined in one of two ways: Enter in the distance from the top of the boss to the positioning face, or select a mating face (a plane won’t work here).
Depending on your choice of a screw or pin boss, your next choice is for dimensions of the boss. These are all pretty self explanatory given the graphics in the PropertyManager. It might need to be mentioned that the hole given by dimension G will create a through hole through the outer face of the part.
The Fins are the supporting ribs around the base of the boss. The one thing that’s not really self explanatory here is the first selection box, which is to establish the angular direction of the fins around the center of the boss. I used a straight edge in the model to establish this direction, but you can use a sketch line, an axis, a plane or planar face.
The resulting boss with ribs is pretty nice, considering it basically walks you through a wizard to do it. If you need something more customized, you can at least have a nice starting point to work from.
The one additional thing I wish they had included here would be fillets, especially a fillet at the edge created by the screw hole. But then again, best practice says put the fillets at the end of the tree.
Don’t forget to use the Favorite option to save your settings. If you’re interested in saving time, saving out Favorites especially for complex features like this will be some low hanging fruit, especially the more you do it and the more standardized your work is. At very least, a standard Favorite can get you in the ball park of the settings you want to use.
