Subassembly Composer Targets Sucks

When using Subassembly Composer you quickly realize that targets suck big time. The call to check if they are valid is .IsValid. Unfortunately this only checks to see if it was assigned to the region, not if the target was found at a particular section. This has disastrous results when trying to do a design, because the cause of the issue isn’t readily identified. Often times an error message is sent to the Event Viewer, but you think your SAC is correct since you included the check for .IsValid.

In order to get around this pain in the butt, since Autodesk appears to have no inclination to correct the call, is to create an Auxiliary point that uses the target. If the elevation of the Auxiliary point is a dummy value we will enter then the target isn’t present and we should adjust for it, if an elevation is found that will then mean the target is there and should be used.

The first thing we need to add to our subassembly is an Auxiliary point that is from the origin or any other point.

Then add in another Auxiliary Point that is going to go from AP1 down to –1000, unless it finds the target in which case it will have the correct elevation.

Then we need to add in a Define Variable to get the elevation value. I used this formula and name. Although you can use a decision or something else to get your design intent.

Disclaimer I did not test this particular subassembly, my math may not work and I might need to adjust the expression to be what the actual value is. But the concept is sound and I’ve used it in other subassembies.