Flexibility not working properly in inventor - BUG that has been there for ever

[Cris-Ideas]

Hi,

I am trying to use flexibility feature but every time I give it a chance it fails me. There is a bug somewhere in inventor that makes it not capable of properly solving assemblies with flexible components.

This time I have run on to this issue with a very simple assembly, had been able to reproduce this buggy behaviour  tens of times, and had made video for you.

After unsuccessfully trying to post this I thought I will make another video for you so you could clearly see what is the difference when assembly is flat.

Here it is.

Here I have uploaded data set for you to play with :  http://a360.co/2fmTsvD

And in case you also think this is not working properly you can support idea to fix this: Fix flexible assemblies !

Cris.

[Anonymous]

I agree, I can "fix" Flex as well...after it fails, explicitly open every assembly that fails, hit rebuild all (for every one) and then it's fixed!......until next time. I don't want to get into the fray, but if Flex doesn't work every time, then it doesn't work. 

[jletcher]

Here is a video turning on flexible then placing no errors.

So now I proved it works your way.

My workflow is perfectly justified as I am not doing anything that software forbids.

If it is not working the software forbids it to work that way.

It is you workflow that makes this example work, but in real life this would be only temporary.

How would my way working be temporary? And it is not real life it is a computer animation nothing real in there. In real life you are not going to make a bolt assemblies.

But in my video doing your way notice how the nut and washer walk further away, this is why you would not turn flexible on till it was located in on spot. The washer and nut could have flown off 500 feet away from where I was working and I would have to track it down.

But anyway here it works your way as well.

[Cris-Ideas]

Situation when it is enough to open end edit all flexible components to get everything back on track is annoying and not acceptable but not worst of all.

When top level assembly is complexed and involved many flexible components it may be destroyed to the point when there is not other way than to rebuild it from scratch.

I have presented such cases in "Flexible nightmare" thread.

Bug behind flexibility failing in basic cases in the same that makes complexed assemblies fail. Only in small once it is much easier to track down.

That's why I make this simple examples and show exact workflows that lead to errors.

Cris.

[Cris-Ideas]

Are you really not able to follow exact same workflow as shown in my video?

It seems you are not.

No further comment.

Cris.

[jtylerbc]

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@jletcher wrote:

But in my video doing your way notice how the nut and washer walk further away, this is why you would not turn flexible on till it was located in on spot. The washer and nut could have flown off 500 feet away from where I was working and I would have to track it down.

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@jletcher, @Cris-Ideas,

Minor side note to what you guys are actually discussing, but the "flying off" issue is easily fixed by adding some face-to-face Mates or Flushes in your bolt assembly, and using one-sided Constraint Limits to control how far the nut and washer can actually move.

In your case, you would add a Mate between the inside-facing surfaces of the washers, and activate a Minimum constraint limit of 0 (leave the Maximum deactivated).  Then do the same using a Flush between the outside face of the nut and the end of the bolt.  For the Flush, the Maximum would be 0 instead, and the Minimum left inactive.

The end result is that the nut and washer, even before you add any constraints at the upper assembly level, can only move as far as the length of the bolt allows, so it can't really get lost in the rest of the assembly.  I use this method for subassemblies of hydraulic bulkhead fittings, which are a similar situation except without the washers.  Works great there, would probably work here as well.

[Cris-Ideas]

@jtylerbc

Thank you for the suggestion.

The last example is done with bolt assembly that can flip because I did recreate example of Kirks bolts (few post earlyer).

In my original flexible bot second washer and nut are fixed from flipping.

But in any case flipping or limits is are not the issue here as error message is not related to any of those.

Unfortunately latest posts had driven this thread of topic. I am not particularly happy with that.

Could you assemble the bolt and upload it so I could have a little play with it and check how it will work?

I am on 2017 so if you are on newer just make as short video so I can reproduce.

Cris.

[jletcher]

  What are you talking about I turned flexible on before I placed the part.

 Just like you wanted and it did not fail.

 If I follow your steps it will fail you proved that, why does any one else have to prove your workflow is a failure?

 I am not understanding why you even made this thread now.

[Cris-Ideas]

Just the opposite,

I am showing a consistent, fully reproducible way of getting error.

If you go threw this thread you will find numerous confirmations from Johnson that documented behaviour proves there is a bug.

Also I have supplied numerous support cases with videos and data sets from this thread and there are many bad behaviours confirmed by autodesk customer support.

So I advice you to go threw this thread from the begging and try to understand, as you insist things are working when they are already have been confirmed as bugs.

If you please stop posting in this thread, and start your own so we can post useless there instead of messing this one.

Please post link to your new thread so I can join.

Cris.

[jletcher]

 This whole thread is useless it should be in the bug reporting section not the help.

You make it sound like flexible is not working and want help to make it work.

But it does work 100% just your workflow is the failure not the feature.

And now you get an upset because I did what you ask for:

"Flexibility not working properly in inventor"

It does work you just found your workflow bugs it out, you are wasting everyone's time with this in the help section it should be moved.

[jletcher]

@jtylerbc

 I don't have an issue, I would not turn flexible on till I constrain one side. I already proved there is no issue with flexible unless you do everything wrong to make it fail.

 @Cris-Ideas issue is he wants you to see the bug, he does not care you can make it work without errors.

This thread should be in the bug section not the help section.

[Cris-Ideas]

You did not do what I asked you even once.

1) you was not able to follow exactly the same workflow as I present. And I know why, because than it would fail and you would look stupid.

2) You are still posting her although I asked you politely not to do so.

If this thread is useless for you and you can not help me, as we have already established and agreed on, so I ask you politely again to live it alone and do not place any more posts on it.

We are all very grateful to you  for your input in this matter.

Cris.

[Frederick_Law]

I'm starting to agree with James on a few things lately.  Gotta stop using Solidworks.

Flexibility is working.  "Not Working" is how constrain is resolved.  Its "" because I don't think it doesn't work, it just doesn't work the way we want.

The problem is when there are multiple solutions to resolve a constrain.  For example, the axis constrain and angle constrain.  There are 2 solutions.  Hence I avoid angle constrain.  I'll put angle in Master Sketch and constrain to that.

Avoid the problem.

I've also used max min in face-face mate for my flexible cylinders.  This eliminate rod pulling out and flip to other side.  It also let me know if my assembly is trying to pull the rod out, mate to the rod eyes will have error.

Even the cylinder won't flip, the assembly still will.  I have a cylinder driven miter saw which pivot on a pin.  The cylinder is assemble on top but it'll still work in cad if the cylinder is rotated to the bottom.  Not in real world since it'll cause collision.

Reason for multiply solution: under constrain.

How to avoid it: Add a directional min max angle constrain between the saw and mounting plate.  Or another dummy cylinder so the saw can't go to the wrong side.

I've set Positional in the assembly but it'll still flip to the other side when I try to move it.  Even when its not flexible.

It is a problem AutoDesk should find a solution so it more usable.  I don't think its easy.  Collision and interference detection could help but it could slow everything down to unusable.

At the mean time, I'll close the assembly without saving when it move out of shape and open it again.

Walking  around the problem.

And go back to SolidWorks   Anyone wanna join me?  Or switch job?

[jletcher]

@Cris-IdeasSaid:

You did not do what I asked you even once.

This was your 1st post.

Hi,

I am trying to use flexibility feature but every time I give it a chance it fails me. There is a bug somewhere in inventor that makes it not capable of properly solving assemblies with flexible components.

I have shown you it works it is your workflow that fails not the feature. If you don't want to learn how to make it work you are wasting eveyone's time.

1) you was not able to follow exactly the same workflow as I present. And I know why, because than it would fail and you would look stupid.

  I am not here to make things fail I am here to help make thing work like you asked. Your workflow and the way you constrain things is the failure not the software. So why will I follow your failures?

You also don't have to insult people that are trying to help, but again you don't want help if you did you would be very happy I gave you the workflow to make it work.

2) You are still posting her although I asked you politely not to do so.

 Calling people names is not politely asking.

If this thread is useless for you and you can not help me,

I did help you I shown you the way you are doing it is the failure not the software.

as we have already established and agreed on,

There is no we in this agreement, I shown you the right way but that is not what you want. You want people to believe Inventor does not work but it does, the workflow fails.

so I ask you politely again to live it alone and do not place any more posts on it.

Then stop replying to my reply I will always come back to if you do. Especially when you are trying to make it look like I failed and I did not fail I shown you it works just like your 1st post ask for.

  You think it is a bug, it is not a failure of the feature but the method you did.

This should be move in the bug section you refuse to see and accept it works great if done the correct way.

[jletcher]

I'm starting to agree with James on a few things lately. 

I bet that was hard to type

 Sad to say not a lot of people need help in Solidworks I only have 1 client in that. Now Creo  has hopes been getting calls on that.

[Frederick_Law]

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@jletcher wrote:

 Sad to say not a lot of people need help in Solidworks I only have 1 client in that. Now Creo  has hopes been getting calls on that.

---

Take a look at Solidworks forum.  They're worse then you 

One guy using goto all over the place in macro and wonder why he got infinity loop.

Please excuse me, I need to go to Anger Management session.

[Cris-Ideas]

What are you doing?

Is there any particular reason why you try to force me to use your solution that do not work?

I have tried your way many times but this is just not working.

Fact that you are able to place a flexible bolt in a hole for the first time proves nothing. I can place this bolts in hundreds of ways, when they fail I can still fix them. But they fail, as well as jacks, and a lot of other flexible stuff.

If you manage to use it in all situations during assembly life this will prove.

I have showed many examples where perfectly healthy assembly is just solved wrong.

If yo want to continue please just start your won thread. Lets say "Flexibility is awesome by jletcher".

Cris.

[jletcher]

@Cris-IdeasWrote:

What are you doing?

Is there any particular reason why you try to force me to use your solution that do not work?

 My video proves it works all can clearly see that, I will not force you to do anything, you can sit here till you are blue in the face and wait for Autodesk to figure out how to make your way work. Even though I proved I got it to work that way as well.

I gave you a solution you are unwilling to accept.

Fact that you are able to place a flexible bolt in a hole for the first time proves nothing. I can place this bolts in hundreds of ways, when they fail I can still fix them. But they fail, as well as jacks, and a lot of other flexible stuff.

1st time? I did it 5 times and I can do it 200 times but I proved it works with the 5 times. If you do it my way they never will fail.

I would look into your jack issue but you seem not to agree with changing your workflows to make things work.

If you manage to use it in all situations during assembly life this will prove.

I don't use bolted assemblies, I just thought I would help you get them to work and then I was going to look at your other issues but you seem to disagree on my fixes.

I have showed many examples where perfectly healthy assembly is just solved wrong.

I have downloaded 3 but only did this one and was going to look at the others but you disagree on my fix on this so not sure if you really want help. Would love to help but you have to be open to correcting a few workflow issues.

 But I seen a few things in what I did look at to be a practice I would not teach my clients. Not that they are wrong but that I know more stable ways.

If yo want to continue please just start your won thread. Lets say "Flexibility is awesome by jletcher".

  I don't have flexible issues so no need.

But when you are ready to learn the best practice of flexible PM me, I would love to help.

[jtylerbc]

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@jletcher wrote:

 I don't have an issue, I would not turn flexible on till I constrain one side.

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Yes, you've mentioned that, and I even agree with it.  But the reason you insist on that order is because of the issue of the washer and nut drifting away - you pointed out this issue yourself.  I proposed a method that prevents it from mattering which order it was done in.  It may not help in any way with the flipping issues that the two of you are arguing about, but I didn't propose it as a fix for that.  I proposed it as a way to control the secondary issue of the parts drifting away.

It is particularly helpful in cases where you copy a subassembly that has already been set as Flexible.  The new copy will automatically clone the Flexible status of the source, putting you back in the situation of constraining something that is already Flexible.  This eliminates the need on the subsequent copies to turn Flexibility back off, add the first constraint, then turn it back on.  Less clicks - I thought you of all people would like that.

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@jletcher wrote:

This thread should be in the bug section not the help section.

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The three forum sections listed under Inventor are "Inventor Forum", "Inventor Ideas", and "Inventor Customization".  Where are these "bug" and "help" sections you refer to?  Additionally, in the same general "Inventor Forum" section that this thread is posted in, you have at least 10 topics posted that have the word "bug" in the title or the original post.  Two were posted last week.  If you feel this is not an appropriate location for talking about bugs, why do you keep doing it?

[Frederick_Law]

We should all read our own post and follow our own advice.

People were telling you the same thing before.

When its your problem, someone else need to fix it.

When its someone else's problem, they should ignore it and walk around it.

I'll go back to work on my problems.

[jletcher]

@jtylerbcWrote:

 Yes, you've mentioned that, and I even agree with it.  But the reason you insist on that order is because of the issue of the washer and nut drifting away - you pointed out this issue yourself. 

No I was just pointing out what could happen doing it that way, I never use bolted assemblies so I would never run into it at all.

 I use flexible for hinges I don't recall using it for anything else to be honest, Just one of my clients also does this bolt assembly method.

Where are these "bug" and "help" sections you refer to?

I will have to search back in post I believe it was Curtis that gave me the link I copied it to a note pad but seem to have lost that. He may have the link faster then me looking.

As for the help section that is what I call this forum.

you have at least 10 topics posted that have the word "bug" in the title or the original post. 

If you feel this is not an appropriate location for talking about bugs, why do you keep doing it?

True but only 2 were I did not know if they were when I started the thread I just always put bug and I should not do that and will stop, and sometimes I forget.

I was told they were bugs after the fact, and at that time Curtis gave me the link.

@Cris-Ideas  knows this is a bug in his mind and does not want it to work any other way but the way he wants, as you clearly see I gave him the way but fights with me I did not do it his way to see the bug.