Trouble Creating Joints

[ben.ruppel]

I have previously struggled with joints in Fusion.  I thought I had it figured out, I made notes and a workflow, now a few months later I'm stuck.

Workflow: 

1) new design

2) save design as JointTest

3) right click on "JointTest" and select "New Component"

4) leave default settings:  name of "Component1", Standard, Internal, Activate

5) ensure that Component1 is activated with the circle next to its name in the tree view.

6) in the Solid section of the Ribbon select "Create -> Box"

7) click on a plane (I use xy), drag a rectangle, and perform a pull operation to create a 3d box.  Press Enter to complete.

Now, I would like to align one edge of my box to the y-axis of the assembly (by which, I mean the origin that is not contained in a component.  The "root" of the file.)  After that, I would like to align a face of the box with the xy origin plane of the "assembly". 

I have tried many different things.  There are a ton of variables that may be impacting this operation, which is why I am turning to the forum.  

In my previous notes I thought I had uncovered a huge cognitive disconnect between what I expect (from mates in other software) and how joints actually work.  I think I had previously gotten away by (in the "Joint" dialog box) selecting an item for "component 1", clicking in blank space on the drawing, and hitting OK.   Then I could create a relationship between two joints made this way.  This process doesn't work now, so maybe I was using a bug or I never really understood the system.  

I have created a public link to my simple example file.  Thank you!

https://a360.co/30QV5bh

The user guide info for joints is just a hair shy of what I need to understand them (it doesn't help that it focuses on a cylindrical example while I work with planar relationships 99% of the time), and I am even walking away from Youtuber guides without an understanding.

[laughingcreek]

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@ben.ruppel wrote:

...Now, I would like to align one edge of my box to the y-axis of the assembly (by which, I mean the origin that is not contained in a component.  The "root" of the file.)  After that, I would like to align a face of the box with the xy origin plane of the "assembly"....

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Your still thinking of joints in terms of solid works "mates".  A joint will place point A on componet 1 to point B on component 2.  This point on that point.  that's t it.  It usually takes just 1 joint to define the relationship and constriain all degrees of movement.

[laughingcreek]

just screwin around with joints-

[ritste20]

To clarify what @laughingcreek said about using a single joint to constrain all six degrees of freedom, this is true of a rigid joint only. The rest of the joints are constrained to specific types of movement in relation to the 2 points selected but by itself only the rigid type joint can fully define a component's location in space from a single point.

[laughingcreek]

but just 1 joint.  this is in contrast to solid works mates, which require more than 1 mate to provide the full constraint.

[ritste20]

absolutely, I couldn't even ballpark the number of assemblies I've started with 3 flush constraints on the origin planes over the years.

I can sympathize with the OP though, it took me a bit to wrap my head around joints especially coming from the mates/constraints that you find in other CAD packages...

[ben.ruppel]

Don't assert what's wrong with me (and then you don't even explain anything well enough to back up your assertion), you'll get a defensive response, as follows:   You are sounding awfully defensive, maybe it's because Fusion 360's joint system is incredibly unintuitive?  Like maybe all these huge companies that make billions of dollars have,  over decades, found already found a system that strikes a balance between intuition and efficiency and somehow Fusion wasn't able to do it better?

I'm watching your video and you're just fixing a corner to the origin point 5 different ways and I don't care.  That's not what I'm trying to do.  I want to align an edge to the y-axis.  Do you know how to do that?

It's a box.  There are edges that are parralel to the z-axis.  How does one make one of those edges coincident with the y axis?  How

[ben.ruppel]

The real problem here is, and I think it's incredibly important, is that NONE OF THE DOCUMENTATION OR GUIDES SHOW HOW TO DO SUFF I WANT TO DO.  It's like they're avoiding it on purpose.  The docs seem to play to the strengths of the system and don't address quite common operations such as the equivalent of a face-face mate or an alignment.  These are not crazy operations to want to perform.

All the youtube and online docs I have found give examples that avoid showing how to do X operation from other software the Fusion way.  And yes, I know it's hard for engineer-types to put on someone else's shoes and to communicate ideas clearly, but someone out there has to be talented enough to pull it off. 

It's in Fusion's interest to say "you're used to doing x like this, this is how to do it in Fusion."  There should be a giant stinking billboard with this information plastered all over the documents.

[fusiondesigner]

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@ben.ruppel wrote:

Now, I would like to align one edge of my box to the y-axis of the assembly (by which, I mean the origin that is not contained in a component.  The "root" of the file.)  After that, I would like to align a face of the box with the xy origin plane of the "assembly". 

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Have you tried the Modify->Align command? That should do exactly what you are asking. Select the component, choose Align, and select the source and target points/planes. It should let you choose the root origin's axes or planes as targets. This won't create a joint, will just move the component/body to the desired location precisely.

[ritste20]

Far be it for me to tell anyone what to do or not do. This is only my suggestion.

Don't use the align command for one simple reason. The command is one-time use. What I mean by that is using align to position parts does not create any constraints between the components. After you click okay, you can click and drag the bodies out of position as easily as placing them and by coincidence, you can also do it by accident.

The only way to prevent future movement would be to add the appropriate joints or create a rigid group once you have them all in place. If you do use the align command, you have to be sure to select your components in the correct order (first selection>component to move, second selection>target location). If you make your selection in the opposite order, it will pull your first component out of position where you may have already aligned to other geometry. Then as soon as you are finished placing components, I suggest creating a rigid group to keep them aligned relative to each other, which will make it easier to manipulate orientation in the parent assembly especially if you have multiple sub-assemblies to deal with.

All that aside, I personally prefer to use joints between each component so that I control the motion of the system as I intended for it to work in the real world.

I will try to do a screencast to illustrate this but I've found they take a long time for the recording to be publicly available to post to the forum.

Regards,

[laughingcreek]

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@ben.ruppel wrote:

Don't assert what's wrong with me (and then you don't even explain anything well enough to back up your assertion), you'll get a defensive response, as follows:   You are sounding awfully defensive, maybe it's because Fusion 360's joint system is incredibly unintuitive?  Like maybe all these huge companies that make billions of dollars have,  over decades, found already found a system that strikes a balance between intuition and efficiency and somehow Fusion wasn't able to do it better?

I'm watching your video and you're just fixing a corner to the origin point 5 different ways and I don't care.  That's not what I'm trying to do.  I want to align an edge to the y-axis.  Do you know how to do that?

It's a box.  There are edges that are parralel to the z-axis.  How does one make one of those edges coincident with the y axis?  How

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what an odd reply.

Your last question is "How does one make one of those edges coincident with the y axis? ".  I'm wondering if that's the actual question?  in every single joint application in the video, one of the box edges was coincident with the y axis.  So you must mean something else.  perhaps a picture illustrating what you want.

[ritste20]

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@ben.ruppel wrote:

It's a box.  There are edges that are parralel to the z-axis.  How does one make one of those edges coincident with the y axis?  How

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If I may read between the lines here, are you asking how to use one of the edges of the box oriented in the z direction and align that to the y axis instead?

If that is the case, when you apply your joint, you will find a triad attached to the joint origin that you can use to re-orient the component with offsets and rotation about the z axis according to the joint origin (not the parent origin z axis). The symbol that highlights over the snap points during geometry selection indicates the x-axis of the joint origin with the line through the center of the circle. By extension the z-axis would be coming up out of the center of that origin designator. This is the axis that will provided you freedom of rotation when establishing a rigid joint so you have to visualize how you want you part situated at the end of this operation to decide where to place the joint origin.

You can use any of the grab handles on the triad or the grab handle on the arc to rotate and move the component around relative to the joint origin.

Hope this helps,

[ben.ruppel]

No it is not an odd reply.  There has always only been one question.  You are insane or trolling at this point and I wonder if you ever weren't trolling.

It's a box.  There are edges that are parralel to the z-axis.  How does one make one of those edges coincident with the y axis?  How

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what an odd reply.

Your last question is "How does one make one of those edges coincident with the y axis? ".  I'm wondering if that's the actual question?  in every single joint application in the video, one of the box edges was coincident with the y axis.  So you must mean something else.  perhaps a picture illustrating what you want.

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You are only quoting one of the two sentences that are part of my question, and then you're acting as if my question doesn't make sense.  There are two sentences. 

[ben.ruppel]

Hello @ritste20 , thank you very much for your explanations.  I am feeling really lost and I'm going to try to read over your answers until I understand them.  I also suspect that I'm asking the wrong question, and that maybe asking a different question will help with my confusion, so please do not be offended if you see another post from me.  Thank you again.

[ben.ruppel]

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@laughingcreek wrote:

but just 1 joint.  this is in contrast to solid works mates, which require more than 1 mate to provide the full constraint.

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Okay, but remember that in Solidworks you would choose an axis and an axis and that's all you would need in order to:

• fix the location of a component feature by 4 DOF (the feature can rotate on the axis and slide on the axis)

So then, how many steps (and how intuitive is it) to accomplish the same task in Fusion?

The frustration comes because it looks like you are creating a new goal in order to show that Fusion is superior.  If you would do me the honor of listening to my goal and showing how to accomplish my goal, then who knows how it will look?

Your choice of response makes it look like your primary intention is not to help someone figure out how to accomplish their task, but it is to show that Fusion is "superior."  As once again, you are not addressing how to accomplish the goal, you are picking a different goal and saying that it is easy to accomplish that goal in Fusion.

[davebYYPCU]

Your goal is was ambiguous. Your replies to responders have attitude.

This is not solidworks.

your example just now is a Cylindrical Joint in Fusion. A different goal, now?

Might help...

[ben.ruppel]

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@fusiondesigner wrote:

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Have you tried the Modify->Align command? That should do exactly what you are asking. Select the component, choose Align, and select the source and target points/planes. It should let you choose the root origin's axes or planes as targets. This won't create a joint, will just move the component/body to the desired location precisely.

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Thank you very much for your response.  Others have mentioned that Align won't fix the component in space (unless they are missing some options), but it will be very useful for me to be able to use Align.

[ben.ruppel]

@laughingcreek 

Ok I've spent more time trying to understand where you are coming from. 

Look, I am using a very simple example (a box) in order to understand a procedure.  You appear to be stuck on the WHY instead of the HOW.

A typical method of troubleshooting in engineering is to reduce a problem to its simplest form before asking the question.

Other people would have asked me to reduce the complexity of my example if I had provided a complex example.

If I had inserted a more complex example, like a Car, and asked how to use joints to align the axle to an axis, it would have provided more room for confusion about the question.

I think the most important thing that is missing from our communication is that: 

I am asking how to align a Z-axis edge of the box to the Y-axis.

I am phrasing the question like this because the answer to this will answer my more complex problem.

When you look at the simple example, and analyze it literally and say you can't tell WHY I want to answer this simple question, you are missing the point.  The point is to figure out the procedure, not to solve a particular problem. 

The question is about the procedure.   Trying to figure out a reason for the question and getting stuck on logic because I haven't provided the more complex real project is just going to cause problems.  

The answer will be best found by taking the goal for granted.  When you look at an algebra problem, you don't ask WHY you want to solve x for y do you? 

When you travel down the road of WHY I want to accomplish my goal, that's opening a can of worms.  Then you need to start arguing about all kinds of philosophical things.  I have posted another topic in this forum where where I am asking about fundamental procedures in Fusion, and that other topic would be better suited to the way you are approaching this question.  https://forums.autodesk.com/t5/fusion-360-design-validate/how-to-position-parts-so-i-can-design-betw...

[ben.ruppel]

Dude, that's your opinion and a pretty poor one at that.  Align an edge to an axis.  That's not ambiguous.  That's as freaking simple as you can get.

Edit:

if I asked how to solve an algebra question and used x and y, would you call that ambiguous?

z-axis edge.  y-axis of origin.  Make them align, or coincident, or whatever to fix that edge on that origin.  

[ben.ruppel]

Do you know why my replies have attitude?  Well for one thing, I suspect there is some auto-translation going on that I don't see.  I HOPE translation issues are causing misunderstanding, and if that is the case, this forum should let people know when translation is happening. 

Another problem is with respondent comprehension and problem solving skills.  I start with a simplified goal because I'm trying to learn a concept not a particular solution, but people are getting hung up on the WHY and not the HOW.  Other people simply don't read what I wrote.  

But the biggest problem of all is what you yourself have said:

"this is not solidworks"

THIS ENTIRE FORUM NEEDS TO STOP WITH THAT LINE. 

Is it helpful or informative to say "this is not solidworks"?  What is your goal then when you say that?  Telling someone they need to think differently isn't helpful unless you BACK IT UP WITH ANYTHING HELPFUL.  That line gets used as a crutch over and over again.  While the responder can't manage to understand a problem, they're sure enough glad to tell you that this isn't solidworks.  Why not just add it to your sig? 

While we are on the topic of that line, why not be more accurate and say "this is not Solidworks, this is not Autocad Mechanical, this is not FreeCAD, this is not Inventor, this is not CATIA, this is not EVERY SINGLE OTHER CAD DESIGN KNOWN TO MAN".

You live in a world where EVERYONE ELSE knows a different way, so you don't get to be cocky with this "this is not Solidworks" line.  FUSION is the program that has to SHOW JOINTS ARE USEFUL, NOT THE OTHER WAY AROUND.

If I invent a new way to drive cars, and people don't understand my new way, I DON'T GET TO TELL THEM "this is not old cars" AND ACT COCKY ABOUT WHAT'S WRONG WITH THEM THAT THEY DON'T UNDERSTAND MY NEW WAY TO DRIVE CARS AFTER A CENTURY OF PEOPLE KNOWING HOW TO DRIVE CARS THE OTHER WAY.

If I invented a new way to drive cars, then I would start with "you used to turn left at an intersection this way, with my new system this is how you would accomplish your goal" 

A person with any kind of any intelligence would recognize how things work in EVERY OTHER PROGRAM, and then try to TRANSLATE THAT into Fusion.