Flexible sub-assemblies

I have a sub-assembly that I want to move dynamically in an upper
level assembly and there are multiple instances of this sub-assembly
that need to move independently of each other. I can get this to work
for just a few seconds then I get warnings from sw that the component
is fixed and cannot be moved.

What I have been doing is selecting each instance of the sub-assy that
I want to set to flexible, rmb, component properties then set them to
flexible. I then move each one at least once to make sure they are
flexible, and they all move correctly but the next time I try to move
those same sub-assys (just a few seconds later) they fail to move and
I get the warning that the components are fixed and cannot be moved.

Is this a known issue? Is there something that I am doing wrong?

Thanks

 

Did you make all instances flexible?

TOP

 

Yes, all instances were set to be flexible.

 

hi there,

try to set all components from base assembly to be Float.

 

Flexible subs is less than a success in my book. They tend to stall
and act in ways contrary to their billing.

For simple mechanisms, I install some of the sub's components
separately and mate at the top level assembly. The sub's components
are added as envelopes so they do not show up on the BOM.

An example of this is a linear actuator motor in a lifting mechanism I
am working on. The extending arm component of the actuator assembly
is added as an envelope and mated to the actuator assembly to control
length with a limit mate. This is a PITA work-around but has been
more robust than flexable subs for the long game.

 

Thanks for your feedback guys.

John and Tick, I think I am in agreement with you guys that I am
probably not doing anything wrong and that flex assemblies are just
not robust enough.

For a little more insight into what I am doing (or trying to do), I am
trying to model an automated cnc assembly line that has a conveyor
(the conveyor is just a part file with no movement), 8 instances of
the same robot that I want to be able to animate independently of each
other and 10 or 12 cnc machines that as of now will not be animated
but at some point we may want to simulate their movements as well. My
assembly structure is as follows.

AssyLine<top level assembly>
AssyLineConveyor<multi-body part file representing conveyor>
MachineAssy<assy file containing robot (the robot is an assembly with
a underdefined config named "Free Drag", cnc machine that the robot
feeds and everything else related to either the robot or the cnc
machine; such as electrical cabinets, hyd tank etc...Each MachineAssy
has a config named Free Drag and the robot is set to its Free Drag
config and set to be a flexible sub-assembly for the MachineAssy Free
Drag configuration>

For this particular assembly line there will be at least 10 machine
assemblies, so MachineAssy01 through MachineAssy10. What I had hoped
to do was to set each of the 10 machine assemblies to their Free Drag
configurations (which in turn references the robot assembly Free Drag
config and is also set to be flexible) and set each one to be Flexible
so that while operating in the AssyLine assembly I would be able to
move the robots for each machine assembly. As I noted prior this does
work but only for a few minutes and eventually the robots quit
moving.

The next thing I tried was to dissolve the MachineAssy assemblies
incontext of the AssyLine file so that now there are no MachineAssys',
now I set the robots to be flexible (the robot is still a sub-
assembly) and that seems to work ok so far but I do not like having
all this data in the top level AssyLine document. It does not give me
the ability to open each machine assembly with that machines robot,
electrical cabinet, hyd tank etc..., I have to open the entire
assembly line just to work on one machine.

As usual there is always some give and take, it appears that if I want
the ability to animate the robots incontext of the assembly line I
will need to give up the machine assembly organization...


Sam