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.

[johnsonshiue]

Hi Cris,

The updated assembly can be found on Fusion Team, https://autodesk2701.autodesk360.com/g/all_projects/my. Just log on and go to "Shared With Me" section. It should be there. The zip file is about 120MB.

Many thanks!

[Cris-Ideas]

I have simplified the crane problem.

And it turns out there is some weird mathematics in inventor constrain solver.

Pay attention. I have a constrain that is perfectly fine to be 25m, and I am able to change it to -25m but than I am not able to change it again to 25m

What a nonsense!!!

Is it really not possible for ANYONE form Autodesk to explain this to us?

You have a simplest possible assembly here 3 parts total.

ARE YOU Autodesk ABLE TO EXPLAIN why constrain solver behaves like this?

Cris.

[cadman777]

Autodesk Development 'Team' should add you to their R&D.

You're doing the work for them!

[johnsonshiue]

Hi Cris,

Many thanks for sharing the example! I think I have seen such behaviors while recording the video. It is a bug or a limitation with Positional Overrides. The issue here is that POs are fed to the solver as the initial position for the components. Then the solver solve the constraints based on the initial position. If the overrides are all constraint based, such behavior may not be easily seen I would assume.

Unfortunately, at the moment, I am not aware of a better solution than the one shown in video I recorded earlier.

Thanks again!

[cadman777]

I have a much better solution.

I stated earlier on.

FORGET ABOUT POS-REPS, b/c like other functions, THEY SUCK!

(That is, if you do more than one per assembly.)

Instead...

You create one assembly for EACH pos-rep.

Then you create one drawing for each assembly.

Here's what you do:

You create the first assembly + drawing.

You copy that pair, then change their names to #2 or something like that.

Then you open drawing #2 and swap the existing view's assembly to assembly #2.

(I do this the 'long way' b/c of Inventor 2010,)

Then you change that assembly's pos-rep to POSITION #2.

Then you repeate the process until you've completed all of them.

When you're done, IF YOU WANT (I don't b/c of overhead), you can compile all drawings into ONE drawing file.

NO BIG DEAL.

I posted a pdf of a 'manual' I did like that that, which was sent along w/the job for the guys to use in the field.

What's so difficult about that?

No more bulls**T fiddle farting around w/Inventor's long-standing DEFECTS.

No more AGGRAVATION and CUSSING.
Once I settled myself on the idea that Autodesk doesn't give a g.d. about it's customers, and that I was STUCK using this not so bad POS 3d modeler, I invented ways to use CORE INVENTOR to do what I needed done. And my method doesn't take a whole lotta work or time. It's just STUPID that it's come down to this, considering the PILES OF MONEY for SUBSCRIPTION + SALES that has flowed into Autodesk coffers over the decades!

Incidentally, this is one more thing you can try, IF you wanna go through all the trouble:

Make an ANIMATION.

Segretate your CONSTRAINTS so they operate at the heart of the assembly motion (for example, you put an ANGLE constraint right on the centerline of the crane's cab pivot point, and another ANGLE constraint btw the boom and base, and a MATE constraint btw the 2 boom segments, etc.). Then you activate each constraint sequentially (or in tandem) using STUDIO.

That way, you can make a VIDEO out of it.

But it's a TON of work!

I've done that before, but prefer to use the previous method due to the time and work involved with Studio.

[Cris-Ideas]

@johnsonshiue 

Johnson,

Please watch the video carefully.

Problem is in the assembly that has NO POS REPS and NO FLEXIBLE components.

So this is CLEARLY NOT AN ISSUE with POS REPS limitations as you suggest.

@cadman777 

Thanks for suggestions.

However this thread was intended to clear some points telated to flexibility it is more and more obviosu that only conclusion is that POS REPS and FLEX do not works at all.

Furthermore as it becomes also more obvious there are obvious errors in constrain solver that show themseleves on a very basic level in simples assemblies possible (like the one from previous video).

So overally I am really giving up hope to find constrain solver really working.

And also I am giving up hope to hear any explanation from Autodesk.

It is so sad.

It is so sad because

fristly answers could be given and surey there are people available that are able to explain why constrain solver behaves this way,

and secondly it is so sad because it is a perfectly fasible task to make a constrain solver that actually solves asssmelbies in all cases.

But as we clearly see Autodesk is not interested in any of the above.

Cris.

[johnsonshiue]

Hi Cris,

I don't fully claim that I understand the issue. But, my speculation is that this may not have anything to do with PosRep or Flexible. It could be related how the constraints are solved. I am sorry I don't have a good solution unfortunately.

Many thanks!

[Cris-Ideas]

So please at least explain to us, or find someone who can explain, how exactly constrains are solved so we are able to avoid this bugs.

Cris.

[johnsonshiue]

Hi Cris,

If possible, please contact Subscription Support and report a case. My forum engagement is usually geared toward quick solutions. This particular issue requires significant efforts to debug and track. Please report it accordingly.

Many thanks!

[Cris-Ideas]

@johnsonshiue 

I have been reporting this issues through Subscription Support for years (as you very well know), I also tried my reseller and other possible and impossible channels.

There is no result from that, not even a reasonable answer with explanation.

Most of the answer you get from Subscription Support is " This has been reported, Case closed - change request" And that's all.

Point that I am constantly bringing up, every time I encounter this buggy behaviour of Inventor and every time it costs me a lot of time (and money), is that Autodesk is well aware of this bugs and does nothing (nothing really significant) for years, not even explaining users WHY this kind of solver issues appear and DOES NOT even try to make users lives easier in this way.

What you can do easily is to find someone dealing with constrain solver in the inventor team and ask this person to give some real technical explanation to all of the users here on this forum.

This way it will be helpful to everyone who experiences this issues, assuming one will look for answers.

Cris.

[cadman777]

Hey Cris,

During my early days of using Inventor I ran into this same issue (Autodesk's unresponsiveness). After 2 years on Subscription (tech support + annual upgrades) I cancelled it forever b/c tech support sucked, and (for the most part) I knew more than they did about their own software, especially the DEFECTS. I quit writing up those long emails about what's broke and HOW TO FIX IT (which I never got any credit for or MONEY, by the way, even though one of their white papers on the piping module nearly quoted verbatim one of my emails!). So, way back then I figured out that Subscription was nothing but a money-maker for the Investors, and that Autodesk didn't give a shyt about their customers, I decided to quit paying them if at all possible. Since then Autodesk became a publically traded corporation, which means they're controlled by INSTITUTIONAL FUNDS, which means most likely GOVERNMENTS. That is another subject for another day, due to the WORLD POLITICS involved.

The result of my 'bad relations' with Autodesk (both AutoCAD and Inventor, and how they screwed their customers and VARs like McNeel) was DO NOT SEND THEM ANY MORE MONEY IF YOU DON'T HAVE TO. Hence, I still use 2010 to this day. Unfortunately, Autodesk extracted a good 2 decades of money out of me before I woke up!. If everybody 'was content with what they have' instead of 'believing in' the LIES that Autodesk peddles year after year about Inventor, Autodesk would have either gone out of business or would have changed their corporate policies to at least 'throw us a bone'.

But since the criminal syndicates that control the USA (the 'idle rich' + government) are 'backing' Autodesk (in a round-about way like mafia protection rackets do), the 'business brains' at Autodesk cooked-up a scheme that we now know as perpetual Subscription. Let's face it, SUBSCRIPTION IS SLAVERY. This is something Lord Coke petitioned Parliament to stop because he saw how it was destroying feudal England. He called those 'guilds' MONOPOLIES ON LABOR. In this case, it's a monopoly on 'THE TOOLS OF THE TRADE'. These monopolies are an ancient business model of CONQUEST, which I hope you realize.

So today, the Criminals at Autodesk have basically ENSLAVED THEIR CUSTOMERS, and nobody's saying a peep. Apparently all their customers would rather SUCK-UP to Autodesk than BE FREE. In any case, the fact that Autodesk shoved perpetual Subscription down their customer's throats and is getting away with it tells us two things: 1. Subscription Slavery is the only way to ensure perpetual revenues for Autodesk's investors, b/c apparently too many of their legacy customers were 'jumping ship', due to waking up to the fact of Autodesk annually SWINDLING their customers with their 'upgrades', and 2. Autodesk gambled on the majority of their customers and on the new generation of customers (ignorant of all this racketeering) being 'faithful', AND THEY WON (or at least it appears that they did). This is the STRONG ARM business model. It's one step short of mafia thuggery: it lacks the physical violence. But the BUSINESS VIOLENCE is easy for anybody to see.

The fact that nobody in here talks about this CRIMINAL EXTORTION RACKET, and everybody in here just 'plays along' shows me what we're dealing with. Do I need to say what THAT is? I won't.

The result of Autodesk's NON-RESPONSIVENESS is, I sought another venue for support, which are the AutoCAD and Inventor Forums. This forum is a very nice method of finding WORK-AROUNDS for perpetual DEFECTS in Autodesk's shoddy software. This forum is also a modern day form of SOCIALISM. It's all political, even though most in here would be loath to admit it. There is only one solution to it, since nobody is willing to 'put their foot down' and 'just say no' to Subscription Slavery. The solution is BREAK UP THE MONOPOLIES ON LABOR and return to 'if you don't work, neither shall you eat'. Investors certainly DO NOT WORK FOR A LIVING, which is why they US Congress called them 'the idle rich'. The Investor 'business model' is a perfect example of a modern day EXTORTION RACKET. If you want me to get into the LAW of it, I will. But at this point, I'm thinking most people in here reading this are saying to themselves that this guy's a bit loony, and this message will likely be flagged by the moderators, or I'll be told to go into the LOBBY and chit-chat there about all this irrelevant psycho-babble. So much for the female mind!

If I was you, I'd save my LIVER the trouble of all those constricted blood vessels caused by the ANGER this situation causes, and learn to live with CORE INVENTOR, and learn to live with all that LOST TIME, LABOR AND MONEY which Autodesk robs from you annually. Let's face it, all the added trinkets in Inventor are only really only good for 'light work', b/c they're really half-assed shyt that Autodesk added to 'show face' to PROSPECTIVE CUSTOMERS in order to 'get them on the hook'. We all know that once we have a certain amount of Inventor-generated DATA, and once we and our 'employees' (slaves) have grown accustomed to Autodesk's software, it's gonna take 'hell and high water' to get things changed. So once they get you ADDICTED, you're screwed. That's why the vast majority of Inventor's functions are TRINKETS. They're designed as MARKETING TOOLS, plain and simple.

CORE INVENTOR ALL THE WAY BABY, and forget about all that frivolous garbage that doesn't do anybody any good in PRODUCTION DESIGN AND DRAFTING. And if that doesn't work good enough for you, you can get someone to code you some VBA or C#. That's what I did, and it 'gets me by' (barely!).

Cheers...

[CGBenner]

@cadman777  @Cris-Ideas @WHolzwarth @swalton @johnsonshiue 

Tagging everyone because I do not want to point fingers at anyone.

This thread is very quickly getting out of control.  It is becoming unproductive, and seems to be moving toward personal attacks against individuals and Autodesk as a whole.  I get that you are frustrated, but making demands, accusations and simply venting anger are not going to solve anyone's problems.  I'm asking you all to please keep the tone of this thread professional and productive.  Everyone just take a deep breath... back away from the keyboard for a few minutes... and let's see if we can get this train back on the tracks.  Thank you.

[johnsonshiue]

Hi Cris,

Please do not get me wrong. We have every intention to review the issue and fix every bug. You may not want to admit but quite a few issues reported within this thread have been resolved as of Inventor 2021. I hope you can recognize it. It was significant investment to solve those issues.

We also have other users to work with. You are not the only one, though you are very vocal about your issues and I think everybody can agree with that.

Before involving other team members, I would like to take a closer look at the issue #295. I did take a closer look. I think I may have found some interesting facts.

1) Open crane flex 1.iam.

2) Edit Angle1 constraint -> change the maximum from 80 to 180.

The errors you are seeing will go away.

Can you confirm that? I suspect the original Limit range (0 to 80) was too restrictive. It blocks the crane from moving or rotating in certain way and the solver deems it unsolvable. I am just speculating.

Many thanks!

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Due to the age,length and tone that is developing here we are closing this thread to additional replies.

DA