How do I solve this mess please?

[lemelman]

I'm sorry to bore you with this pipe wheelchair again, but I'm really stuck.

I changed the joints to rigid and started to make some good progress, but then realized the pipe lengths were not quite right. No problem, I thought, just parametrize the pipe lengths and change them. But when I did that, the whole thing just "exploded". I then deleted all the joints and started rebuilding, but the basic 4-pipe frame is out of alignment. I grounded the first pipe onto the Y-axis and aligned each connector with an origin plane, then proceeded to join them up with rigid joints. Each joint is oriented at an appropriate multiple of 90 degrees, but the last joint turns out to be slightly miss-aligned - as can be seen in the attached screenshots. I've done this three times and get the same result each time.

I'm totally at a loss as to why it's wrong and how to fix it.

One screenshot shows the misalignment of the final connection, and the other shows typically how the other three sides are nicely aligned. (I can only include 3 attachments).

[chrisplyler]

OMG

[TrippyLighting]

I would love to help, but frankly I would have to repeat exactly what I stated in a previous thread of yours where I also created a screencast on how this can be approached using 

I would recommend you re-read that thread then simply implement the advice given.

[davebYYPCU]

`Does this look right?

I have no idea what you will do with the other parts. Light bulbs are off for clarity.

Seems you don't give enough attention to detail. 

If a piece of pipe is to seat in a socket, activate the component, add Joint Origins to the socket component seat, - when you copy the component, they will be there.

I could not see what you had in the first place, can not see how changing the pipe length could blow the model apart, unless you have back tracked and deleted joints or joint origins that you needed.

To fix this, I added Joint origins to the matching face shoulders in the components that needed them.  Then added  joints for positioning 7 of the components.

Might help....

[lemelman]

I tried the joint-origin method, but that didn't work either: it gave the same misalignment as all the other methods I tried. I eventually decided that the problem was caused by the joint connecting the 5-way connector to the pipe - it turned out to be out of alignment by 0.35 degrees. When I edited the joint it said it was at 180 degrees, but with trial and error I adjusted it to 179.65 and the misalignment disappeared. 

This raises several questions:

What does the angle actually refer to? How come that 180 was decided on and why was it not appropriate?

By the way, why do some posts to this forum show pictures and others simply have references?

[TrippyLighting]

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@lemelman wrote:

I tried the joint-origin method, but that didn't work either: it gave the same misalignment as all the other methods I tried.

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I demonstrated that this method works in a screencast and even attached the design so you could study it.

If it did not work, then you should have gone back not your design and studied why it did not work.

[lichtzeichenanlage]

I did this for him in a different thread, @TrippyLighting did this in another thread.... 

[lichtzeichenanlage]

Cleaning up the mess? What's about removing the Capture Position and Ground / Unground features and shortening the timeline by 40+ entries? 

[davebYYPCU]

Sorry to cause confusion, 

your parts went together with no errors, just simply add Joints where needed, not one faltered in the process.  You must have fixed the 5 way yourself, before I got to it.

For a misalignment that small, it is nothing to do with the Joint system, you have a Geometry drama, the joints discs have to align to the two snap positions.  Find the sketch plane error to fix it.

what does the angle refer to?

The orientation of the Joint Disc.

photos in the post - use the insert photo button (camera) in the function bar of this window.

Might help....

[davebYYPCU]

I was aware of that.

I need the challenge of finding the root cause of a problem, (self learning)

just happens detail of the actual problem was not mentioned, it was either fixed, or fudged in an area I did not have to chase.

[lichtzeichenanlage]

That's fine. That's why I did it at some point, too 😉

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@davebYYPCU wrote:

I need the challenge of finding the root cause of a problem, (self learning)

[davebYYPCU]

@lemelman, I don't think you are making any mistakes, I have not found any Geometry errors of your doing see below, Apologies if it came across badly.

Fusion is not behaving as expected.  @jeff_strater, or @Phil.E

for those that wish to debug further as I have to run...

there was a Move Body involving 18pipe - all three instances, I deleted that from the file, as supplied by the OP.

Joints on Component 18pipe1, work fine.

Joints on 18pipe2 and 18pipe3, are introducing a misalignment.

These 2 Components are duplicates of 18pipe1.

After joining pipe2, or 3 the component content, (Pipe and Sketch), is rotating around it's X axis, about 0.3 degrees.

Repeatable as I attempted a midpoint joint on the pipe, to a 5 way and was in error.

I thought it might be a face error on the pipe, makes no difference.

However I was not able to make the joint snap to the Y axis of  18pipe2, to test with the body hidden.

Haven't found the corresponding error in the 5 way faces / origin.

Might help....

[mavigogun]

After reviewing the design on Friday, measuring angles, placing variations on Joints, I discovered what everybody else has: the geometry is defective.   Or, rather, it is exactly as designed.    At that point, travelling, I began contriving a demonstration- but then reprioritized.   

It's easy to get tunnel versioned, designing alone- an extra set of eyes can be a real asset; I've definitely benefited from folks here turning my head a few degrees- you feel silly for a moment, and appreciative, and dust yourself off and get back to work.

I isolated the problem part by Assembling the mess with Joints, then Projecting the geometry to Sketch- made for easy simultaneous comparison of angles and provided a record- otherwise, I would have kept chasing my tail, wondering if a previous Measurement had been taken or recalled correctly.

[lemelman]

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@mavigogun wrote:

After reviewing the design on Friday, measuring angles, placing variations on Joints, I discovered what everybody else has: the geometry is defective.   Or, rather, it is exactly as designed.  

Sorry, I'm confused. Are you saying there's a problem with Fusion, or that I did something wrong?

Since making the 0.35 degree adjustment, everything is progressing well and I'm almost ready to fit the wheels.

JOLT (Just One Little Thing), even if I turn the Joints lightbulb off, all the joint symbols still appear in the model. How can I turn them off? I've tried switching the individual lightbulbs off, but that doesn't work either.

.

[chrisplyler]

Those aren't Joints. Those are Joint Origins.

[lemelman]

Whatever they are called - how do I turn them off?

[chrisplyler]

Each Component that you have added them to with get a Joint Origins header. Expand it and turn off their visibility by clicking on their light bulb icons. Can you really not be bothered to figure something like that out on your own? I mean, I didn't know the answer before you asked the question, so I added a Joint Origin in a file I had open already, looked in the Project Browser, didn't see anything new up near the Joints header, so drilled down a bit and found it. Took me like twenty seconds in total.

[TrippyLighting]

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@lemelman wrote:

Whatever they are called - how do I turn them off?

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They are called joint origins. That is important to kn ow because if you don't know what they are called your only hope to find them is by accident.

Then, as @chrisplyler has already answered, they can be toggled on/off like everything else in the bowser.

[chrisplyler]

And how could you not know what they are called? You had to have clicked on Model>Assemble>Joint Origin to put them there.

[lemelman]

Thank you Peter. It makes sense when you think about it - since a joint origin is an attribute of a component it's visibility  will be controlled within the component's folder. I got so disillusioned by the time I spent tracing the misalignment problem that I rather lost heart in investigating a cosmetic feature.

Joint origins on duplicated components are certainly a time saver.