topic Re: Position Compute failed , not clear on how to resolve in Fusion Design, Validate & Document Forum

Position Compute failed , not clear on how to resolve

Anonymous — Tue, 04 May 2021 22:21:23 GMT

I have a project, that granted I was learning and did not use best practices. That said it was ok was able to animate joints etc. The problems came as I tried to replace hinges etc redo doors that require new hole location components etc. I get many errors. I tried stopping history timeline and that caused a couple issues. So I am back trying to resolve some of the warnings. and see if I can rectify or remove old components. I get position compute failed , I Position 30 etc. I click on the issue in the timeline and click see in browser or edit , but I don't see what it is referring too for me to correct. I am trying to remove some old components (hinges) and delete their holes and joints but can't see my way out. Clearing up these errors might be a help. Attached is screencast.

https://autode.sk/2QTuSqu

Re: Position Compute failed , not clear on how to resolve

Oceanconcepts — Tue, 04 May 2021 22:15:01 GMT

I'm not seeing any screencast, so am not able to comment on specifics. But I will offer the opinion that there are times when the best thing to do is to either:

1) go back in the timeline to where all was well, and proceed forward according to better practices, resolving issues as they come up, or

2) (probably better in the long run) start a new design with your old one open to refer to, stepping through according to best practices. This always sounds like more work than it actually turns out to be, and you will almost inevitably see where things went wrong.

I highly recommend this recorded class from AU 2020 "Debugging Your Fusion Design: Let's get rid of red and yellow features" Jeff and Phil will save you a ton of time.

https://www.autodesk.com/autodesk-university/class/Debugging-Your-Fusion-Design-Lets-Get-Rid-Red-and-Yellow-Features-2020

Re: Position Compute failed , not clear on how to resolve

Anonymous — Tue, 04 May 2021 22:27:10 GMT

Oceanconcepts

Thank you for your response. Not sure what is going on with the screencast but I tried to paste in the tiny url lets see if the forum software allows it. I understand what you are saying about rebuilding, I might need to but I only need to replace a couple hinges and hoped I could clear the current errors which I doubt are meaningful. I expect they relate to no longer used components. My impression is it might be wiser to design outside of Fusion, and execute the final version in fusion. It doesn't seem to love layers of changes. I will look at that video, thank you.

Brad

Re: Position Compute failed , not clear on how to resolve

Oceanconcepts — Tue, 04 May 2021 22:34:30 GMT

Definitely view the video.

What you might want to do rather than design outside of Fusion is to start with history off when you are working out rough ideas. However I think that if you follow the practices outlined in the video- particularly as to how you select references for sketches and positioning components- you will find working with history is a powerful tool.

Re: Position Compute failed , not clear on how to resolve

jeff_strater — Tue, 04 May 2021 23:37:50 GMT

Thanks for the plug, @Oceanconcepts ! I'm not sure that class will address all your problems, but it does give some things to look out for.

Regarding the situation in your design, the failure of Capture Position usually means that some components are missing, or possibly that the Capture is specifying positions that can no longer be solved.

It helps to understand what Capture Position does. This video is pretty basic: https://help.autodesk.com/view/fusion360/ENU/?caas=caas/video/youtube/watch-v-1Tg6XUv1JbI.html

Here is another one by the same person: https://help.autodesk.com/view/fusion360/ENU/?caas=caas/video/youtube/watch-v-vZgX3Rx03Jk.html

The short version of "what is a Capture Position?" is: This feature finds all the components that are not in their "home position", and, as the name implies, records the current positions in that feature in the browser. When that feature is executed, those components' transforms are set to the cached versions, and the system is solved.

There are times when Capture Position is useful, but you do want to be careful not to over-use it. Don't try, for instance, to get around adding joints by moving components, and doing a Capture. That method is not associative to geometry, and can produce unexpected results if the design is edited.

Regarding this design, without knowing more about it, I would try deleting the Captures, and see if A) they are really necessary, and B) whether component positions can be better achieved with joints.

Re: Position Compute failed , not clear on how to resolve

Anonymous — Tue, 04 May 2021 23:52:05 GMT

Jeff thank you

That helps alot. Early on I wasn't using joints as much and was or would get the prompt " things have moved would you like to capture position" which not wanting things to move would select yes. I use joints almost always now ( which creates its own issues) But I know what to look for. When I try to edit the capture position warning I usually don't see anything. Thank You

Brad

Re: Position Compute failed , not clear on how to resolve

Anonymous — Wed, 05 May 2021 09:05:50 GMT

I did find a hybrid solution. Rather than starting from scratch I did a "save as" of component assemblies. These saved files I could clean out old junk, unused components etc. If those errored it was easy to see and ignore. By default a save as has no link to break. Reassembling these chunks was easy as they would usually insert in there original position. As well unfortunate joints between these chunks was broken. There are a few downsides one was often original sketches were not editable, but nothing major. It was nice to get working again.