There is a bug in the Autodesk Inventor Bolted Connection Generator that needs to be addressed. While there are work-a-round’s that can permit the use of the generator with curved faces, these are not convenient or sane, leaving the user to add respective hole features in each part manually. This should be corrected.

Autodesk Inventor Bolted Connection Generator

I am working with an assembly that contains numerous components, two of which have continually curved faces. These need to be fastened together, and I decided that simple threaded bolt option would work well. I wanted to use the Bolted Connection Generator at the assembly level in order to automate the fastener work in all respective components; Grand idea.

Knowing that I needed some feature to seed the generator’s path and start point, I opted to use a pilot hole, having used that successfully in the past. Simply add a small pilot hole in the part which the generator can later ‘latch onto’; this will guide the foundation of the generator process. Furthermore, the pilot hole is nice when you are not sure what size the fastener will ultimately be, but know where you want the hole at the part level. This was opted for in lieu of a point added at the assembly level. I prefer the assembly to be as clean and free of clutter as possible.

All options (which are only a portion of the possible ways to attack this) are ultimately pointless, as the Bolted Connection Generator must have a flat face in which to start the fastener from.

I could have provided a plane at the axis-surface intersection, but that would be a bit clumsy, and the generator will not accept a plane type work feature as an input. However I am not saying that I want that as my solution because that is still junky and awkward.  Also, I could have opted to prime the surface with an extruded tangent face, perhaps the diameter of the aforesaid pilot hole. That would have worked, but would have been a bear to duplicate throughout the design as needed.


What we need is for the system to recognize that I need a ‘Bolted Connection’ along an axis (or hole), originating the start point at the axis to surface intersection. Better yet, for the system to recognize the offset differences along the curve, and compensate a tad bit deeper for the mid-ordinate offset. This would be useful in countersunk and spot-faced applications to ensure the fastener sits perfectly flush. (It’s not difficult to calculate the mid-ordinate offset, but if anyone needs that reference, we have it here (Shameless plug):

Autodesk Inventor Assembly Threaded Hole

As I have written numerous times in the past, I love the Bolted Connection Generator, but this type of awkwardness needs to be addressed as more and more organically-shaped features are being introduced into production.