I have read that it is better to Remove a Body instead of Deleting it because Remove will prevent any downstream errors from occurring. Well, apparently this statement is not completely accurate because a Remove Body has caused downstream errors in a design I’m working on. These Bodies were not Removed earlier in the Timeline but were the last thing done. One of the annoying things about this error is the time it took for Fusion 360 to report them. There was no error when I performed the Remove. Also, I run a Compute All at least twice each time I work on the design. I run a Compute All just after opening the design and again before saving it. And I normally work on the design at least 2 separate times every day. But this Remove Body Lost Reference Error did not display at any of the Compute All’s I ran until 3-days after I Removed the Bodies.
So here are the details. I was adding the Safety Railing to finally complete the design of a new deck for my home. I designed an assembly of a 6-foot-long piece of railing, which is the length the manufacturer sells, in a separate external design. Now all of the spans between railing posts in my Deck Design are less than 6-feet with 4 different span lengths. So, I inserted the first external railing assembly design into my new deck design and broke the link so the length could be edited. I aligned the railing between the first 2 posts with equal space between the balusters and posts at each end. Then I used the Split Body Command to trim off the excess railing using the inner faces of the posts as the Splitting Tool. Of course, the Split Body Tool renumbered the resulting bodies the way it wanted to but the body I wanted to keep was no longer Body 1. At any rate, I then Removed the unwanted bodies with no errors or warnings. Lastly, I aligned the center of the railing with the center of the posts & repeated this process for the remaining different length spans and used Rectangular Pattern where I could for those spans that were equal. As I stated earlier, I did not receive any error messages when I ran Compute All before saving and closing the design. But when running Compute All before saving the design 3-days later, I received the Remove Body Lost Reference to Body 1 Missing Error pictured below with several occurrences with additional warnings and errors on Sketches and Rectangular Pattern Features downstream. It even broke previous sketches that were fully constrained and locked. Though these sketches are no longer locked, they are not generating any warnings or errors, so I decided not to worry about those until this problem is resolved.
This Remove Body Error is a bit perplexing because you can’t edit the Remove Body Feature. You can only Suppress or Delete it to restore the Removed Body and, both of these actions caused additional errors downstream. In my humble and novice opinion, I believe that the problem lies in the way the Split Body Command renumbers the bodies. But again, there is no way to control the way Split Body re-orders & numbers those bodies. I found a response towards the end of this Solved: Split Body naming and remove body with changed history - Autodesk Community - Fusion 360 forum thread that explains how Split Body numbers the split body. He even provides a way to control the numbering using a Surface Patch as the splitting tool. But that part sort of lost me since I rarely do any surface modeling. And I wasn’t sure this would even work or how many additional errors this would create at this time so, I tried something different instead.
I didn’t think that this would fix the errors, but I rolled the History Marker back to the first Error occurrence, deleted the Remove Body 1 feature before the error then deleted the Remove Body 2 Error. I received an immediate warning that these actions caused addition errors downstream but, I soldered on by simply Removing the bodies in the Browser again but in a different order, saving Body 1 as the last to be Removed. Then I advanced the History Marker to the next Sketch Projection Lost Warning and fixed it. I repeated this process for each Remove Error and Warning downstream until all appeared clean. I advanced the History Marker to the End and ran a Compute All. Surprisingly, no errors or warnings were returned. So, I saved the design and went to bed with my fingers crossed. But, about 3 or 4 Compute All’s later, the errors were back. The only difference being the number of the Removed body in error but still showing Body 1 as the Lost Reference.
As a bit of additional information, the externally referenced railing assembly with a broken link is in a Rigid Group. I didn’t think this mattered but as a test while attempting to repair these Remove Errors, I Suppressed the Rigid Group before performing my fix then Un-suppressed the Rigid Group when I finished. I did this for some of the occurrences of the Remove error but did not do it for all the occurrences and it didn’t seem to matter, the results were the same for both methods. Lastly, I can try to attach a copy of my design if necessary but, I must give you fair warning, this is a complex design with a huge Browser and Timeline.
So, in summary, I have 3 burning questions I would like answered.
- What is the proper way to repair these Remove Body Reference Failure Errors?
- Is there a way to specify and control how the bodies get ranked and numbered by the Split Body Command? I would like this answered even if it has no bearing on this error.
- Why does it take so long for Fusion 360 to recognize and report this error?
Thanks, and Merry Christmas to All
Lenny
