Unable to Set Position of Driven Join

[adambwinnett]

Let me preface this by saying that I'm still learning Fusion and CAD in general, so I know I've probably gone and fallen into some trap or boxed myself into a corner of my own making. That being said, if anyone can either tell me how to fix this, or what I should do better to avoid this, that would be great!

So, as part of my learning I've been playing with subassemblies and joints. I went and created a nut component and a bolt component in separate designs. I've then added these to another new design as a subassembly to which I have added a cylinder joint which I have motion linked (I was experimenting with getting the joint to respect the threads of the two components). So far so good! I've then added this nut/bolt subassembly to a plate component as shown below, and have been trying to set the position of the nuts by using the Drive Joint dialog. However, no matter what I try, I cannot get the nuts to remain in place.

If I edit the existing Capture Position feature which was used to move all the imported subassemblies into place, and then drive the nuts to where I want them, after clicking "Final Position", I now have "Capture Position" and "Revert Position" on the tool bar, which tells me that editing the original Position feature didn't work. If I click the new Capture Position button, I get a new feature on the timeline but the nut has jumped back to the original position.

So, what have I done/am I doing wrong?

[TheCADWhisperer]

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@adambwinnett wrote:

…and have been trying to set the position of the nuts by using the Drive Joint… … and then drive the nuts to where I want them…

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I don’t know what this means.

Can you File> Export and then Attach your assembly here?

[adambwinnett]

Here you go, one uploaded design.

As to what I mean by your quoted parts of my post, hopefully this screenshot will help.

If I set the position of the nut using the menu above, it isn't being respected either when editing the original Capture Position feature, or when using the toolbar button that will appear after moving the nut. As I said, I'm aware that it is probably something I've done, or not fully understood about the way Fusion work, so thanks for looking at this for me. 

[davebYYPCU]

Set position of the Nuts by Drive Joint - stands out as the unusual part of the story.

Set the position of the nuts in the Edit Joint Dialogue. Set Offset distances from the Joint disc.

If animating then there will be Joint Limits, and optionally a Rest Position, But didn’t sound like you are doing this - yet.

Ok, your second reply came in while typing.

You are boxed in, you are Driving a Joint in a Linked Component.

For this Assembly you need new Joints that belong to this Assembly, before anything I have said above will make any sense.

Might help....

[davebYYPCU]

I have read your file, nothing here is critical of your model to date.

Original problem is that in general, you can't edit / update a Linked Component, without breaking the link.  You didn't break the Link for your own reasons.

Where is the 3030 rail / frame?  Without them this assembly is not making much sense.

These parts in there own file are fine, but has limitations.

You don't need the Sub Assembly, for what I think you will be doing.  (Nice exercise for what it was)

Building a Machine - make / import / place, one of each individual part.

Pattern the copies.  (Do not Mirror - unless you need left and right handed versions)

Might help.....

[TrippyLighting]

An assembly like your should not include any position capture features.

Use assembly joints to properly position and orient your components.

That joint should be a simple rigid joint. The purpose of the Screw and Nut is to create a static connection.

No motion link needed. 

[adambwinnett]

Thanks for the feedback. What you've said does actually make sense. I think I was working under the false belief that the option to drive a joint would be independent of the assembly the joint was first created in. Obviously that's not the case, and now I know that, I'll just work around it.

To be honest, I don't really need the joints at all. I was just using them as a practice anyway, so I'll remove them.

Thanks 🙂

[TrippyLighting]

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@adambwinnett wrote:

...

To be honest, I don't really need the joints at all. .

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I am not sure ho you came to that conclusion, but but that is wrong!

Joints are needed for any assembly.

[adambwinnett]

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@TrippyLighting wrote:

An assembly like your should not include any position capture features.

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Should not is an incredibly definitive statement. Is there any particular reason why I shouldn't use position capture?

I know the motion link wasn't strictly needed. That was simply me trying to see if the motion of the nut and bolt could be constrained to the actual thread. It was a practice exercise for myself 🙂

[laughingcreek]

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@adambwinnett wrote:

...Should not is an incredibly definitive statement. Is there any particular reason why I shouldn't use position capture?

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this list of reasons is rather long, but at the top of the list is that the positioning of your nuts won't be parametric.

[TrippyLighting]

You should not use position-capture for locating and orienting components, it is not it's intended function and can have undesirable side effects.

The position capture feature captures the position and orientation of every component in an assembly   since the last time a position capture feature was used. Over time with increasing size of assemblies the data the position capture feature captures increases and can drastically slow down assemblies, in particular re-computation of the timeline. 

[etfrench]

I would put each and every move/position capture must be recalculated every time a compute is done at the top of the list.  A compute is done any time a change is made in the file.  Using lots of moves will slow Fusion 360 down dramatically

[JDMather]

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@adambwinnett wrote:

To be honest, I don't really need the joints at all. I was just using them as a practice anyway, so I'll remove them.

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Assembly Joints replicate the real world (more or less) better to get more practice using them.