This is a common question people ask me so I thought I would share my thoughts on the topic of what is the best way to model weldments. There really is not one correct way now with Autodesk Inventor to model weldments. What is the best way depends on how you work and your end deliverables to either your client or your manufacturing shop. Autodesk Inventor provides what I consider four (4) main workflows for creating weldments as listed below:
Option 1 – Single Part
This is what I would call the “old school” method. You would create a single IPT part model that has all of the different components models as features. Sometimes this is the quickest way but doesn’t create complete drawings view because some of the seam lines are missing. Plus you can not take advantage of component instances resulting in a larger and slower model.
Option 2 – Assembly with Part Level Features
This method is the old stand by in most cases and was and still kinda is the most common. Here you would create an assembly (IAM) for the weldment and each sub component is a separate part (IPT). All of your machining features like holes and pockets are placed at the part level using standard part modeling features. This gives you full access to all of the available part modeling features which is very nice. The downside to this process is you can not really create two separate drawings one for fabrication and another for machining. Now if you don’t need two separate drawings for maybe a smaller weldment this is a nice all around method. I do however enable the weldment environment on the assembly just so I know it is a weldment for future use by going under the “Convert” pull down menu and activating the weldment environment once.
Option 3 – Assembly with Assembly Level Features
This method is similar to option two expect you put the machining features at the assembly level within the “Machining” environment within the weldment. This method provides you the ability to create two separate drawings with one just showing the fabrication with no machining and another with all the machining features. The only downside to this method today is that there are a few modeling features not available at the assembly level which sometimes makes it a little slower however in most cases you can model everything. The extra upfront time could save a bunch of time on the drawing side if needed. Also it is pretty clear this is the direction the Autodesk Inventor product is heading so I would guess more and more features will be available at the assembly level soon.
Option 4 – Assembly with Assembly Level Features and Welds
This option is the same as option 3 except you would add all of the welds within the “Welds” environment on the model. This is pretty time consuming so I would only do it if needed. The four main reasons I keep coming back to for this to be worth the time are noted below:
- You need the actual weight of the weldment with weld
- You need the actual CG of the weldment fully welded
- You need to check some clearance concerns with the weld beads in place
- You want to make a cool looking model and have some free time J
Each of the above methods requires different amounts of time to create and provide different end results. I would recommend using method 3 if you need a fabrication and machining drawing then option 2 if you only create one drawing that show both fabrication and machining for industrial machine design. If you had to pick I would go with option 3 because I do believe this will only get easier within Inventor and more assembly level features will be available in the future. So it is the best for the present time and the future for sure.
This is a topic that could be pages long but I thought this brief overview might help and get things going for now.
Dan
