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Make Flexible : is this feature working or not ?


New Member

this is my very first post here (from France).

I have a lot of trouble trying to use the "Make flexible" feature :
context : multi-level assembly (more than 3)
I'm losing constraints located very deep sub-assembly levels when I make flexible a sub-assembly from the top assembly level (while it works well at sub-assembly level).

For 2 full weeks now I made a lot of tests, yesterday I spent half a day with my local distributor support and finally it seems that the only way to make this feature working is:
- remove ALL constraints to any reference axes or planes
- keep only constraints between parts
- never use any anchor (at any level)
Parts looks like floating in the space. It is very difficult to test rotations or sliding because all the assembly moves.

Is this problem fixed now ?
I could not find any "guide" or "best practice" on how to use this Alibre feature. Is it available somewhere ?

Thanks for your valuable help !

Best regards,

PS :
My (brand new) config :
- 16 cores 5Mhz
- 16 Gb RAM
- Nvidia T600 4Gb RAM DDR6
- NVMe
- Win 11

PS2 : not using imported files/STEPS. Only native Alibre geometries

PS3 : failed (spam) to add here links to 4 posts related to this problem, dated 2020


New Member

first, I'm sorry for writing in a bad english, this is not my native language.
second, I'm in a positive attitude, trying to fix problems, not destroying anything. I'm sure Alibre dev team are valuable people working hard to deliver good product.

A quick update from my side :

- A few months ago I was the only Alibre user in my company and finally concluded that I was not using Alibre correctly. It tooks me days and days trying to understand what's wrong in the way I'm using Alibre but I couldn't find any explanation by myself. The only change of behaviour was the repeated use of save button before each new modification (part module is working very well, only assembly module fails), because I had a lot of crash (windows disapear). I also notice a lot of memory leaks, but this has already been raised somewere on the forum.

- Support from local distributor here in France has worked on my designs and gave me some advices without being able to completely explain the right way to use this feature. For example, I've been adviced not using a belt (toroïdal) constrained tangent to 2 coplanar V-groved pulleys, but instead a more simple co-planar constraint between the plane containing the belt and the plane containing pulleys.

- I got a trainee (engineer) working with me since April. He had a Solidworks experience and was positively convinced by Alibre from day one, the 2 softwares being very close in their use. He's working on a totally new design (read : he does not re-use any of my parts / assemblies, he has personnaly designed every part / assembly). All was OK even with a fastly growing design : multi-level sub-assemblies, very large main assembly. Constraints solving was performing very well UNTIL HE USED THE FLEXIBLE OPTION. Since then, he is experiencing same troubles. We had a customer presentation this week and we were not really proud to show a machine with "flying" parts, it really deserves our credibility....

- I have hired a mechatronics engineer this month. He is well experienced with Fusion 360 but we decided to buy another Alibre licence. It took only one day before he got a lot of troubles using Alibre. The big difference is that he is using a descendant approach, starting from the final assembly and designing parts inside this assembly, digging deeper and deeper into the assembly tree. He is using a lot of features like "projected sketch maintaining associativity with parent geometry". Among problems, for example when he moves the part with mouse the assembly stay constrained, but when he uses the 3D cube, a lot of constraint disapears. The only way to recover is to close without saving. The same action while being on the constraint dialog and once having selected at leat one geometry turns immediately into a general Alibre crash.

We have decided not to upgrade to V25, it seems that this new version does not fix the constraint loss problem and that new problems have been raised by users.

The reason why I started with Alibre was it's good price/performance ratio. I've been using it from a long time as hobbyist (well before the Geomagic story !). When I started my own business 3 years ago, It was obviously a good choice to start with even if Solidworks was an option at that time. Solidworks is much better performing but the cost of an Alibre licence is less than maintenance fees of Solidworks...

Frankly speaking, today I'm wandering whether we'll keep working with Alibre. The new engineer has shown us amazing features of Fusion and the total cost is 400€ per year, less than maintenance fees of Alibre, for much higher performance level. The only thing with still hangs this process is that Fusion is a cloud based system and we are working for some industries not very free about intellectual property problems.

I'd be delighted to get a feedback from Alibre team.

Sincerely Yours,


Alibre Super User
Without exposing any proprietary data of your models could you at least upload a screen shot of the problem model or upload similar model for evaluation?
You said that you are working with your local distributor, maybe you could enter a Support ticket with Alibre to see if they can help out.
I know that Make Flexible can have some issues and sometimes it takes a bit of effort to make it work at multiple levels of subassemblies.


Senior Member
I learned this early on. I never use project to sketch within an assembly mode. It just causes problems. It all gets very tricky when you start adding multiple levels of sub-assemblies. My work around was using configurations. But then that doesn't allow you to "move/flex" anything easily.

I have only dabbled with other 3D software, but I always thought that if you made the bolt pattern on part A, and then referenced that geometry on part B, that they would always be linked. That was how I started doing things but it never updated the parts correctly and just did not function well.

The only other option might be using the Global Parameters tool.


Alibre Super User
I always do my work from the ground up. Make all of the parts first and then make the assemblies. I see very few problems other than my own mistakes and issues that have already been brought up
in Alibre Design Expert it self.

I really can't criticize your English. You write better than a lot of Americans I have seen in the past.

Now as for "make flexible": It will absolutely not work if there are any "patterns" in any of your parts. No matter how deep down in the assembly tier they may be. Alibre has always flagged me with
with an error that patterns exist. And with that I must say that "make flexible" works fine on my system. No complaints at all. Also I use it in assemblies that are in the middle, more or less, of the
assembly tier structure. But it has to be "set" in the assembly it is in. I've never had any luck doing it from a higher tiered assembly.

Hope this helps some.

Pick a non-proprietary assembly that is causing you problems and package it and generate a support ticket. Just as Harold suggested. The package will make certain that all of the parts used in all tiers of the final assembly will be included.

Good luck and stay safe,


Alibre Super User
Parts looks like floating in the space. It is very difficult to test rotations or sliding because all the assembly moves.
have experienced the same problem...and found no better solution than you.
I have also build all parts and subassemblies from scratch , no interdesign project to sketch, no pattern, no imported parts, no anchors...
When any movment should be involved, i tend to make these part all in one assembly to avoid this - not the best way, but i haven't found another...