Placing/replacing adjustable parts in assembly

[NZMark]

Dear All,

I am placing a set of adjustable parts in an assembly.

Certain parts will be replaced later with others, such that associative placements using existing part *surfaces* become invalid.

Fortunately, in my case, I can also use reference planes in the parts to perform the initial associative placements, and if I replace these parts with others having the same named planes (x,y,z and some manually added coincidence/parallel ones) then everything works fine.

Except... when I have adjustable parts, the coincidence/parallel planes don't adjust to the adjustable value used in each instance in the assembly (see attached graphic)

Instead, the planes appear in the assembly parts at the position corresponding to the "prototype" part (with a nominal adjustable dimension), not where I hoped for.

I have tried the following, in vain:
1. Parallel vs coincidence - both fail

2. Set position of par./coinc. plane in part using a variable: This also fails, even if I make the plane position variable Adjustable as well and set it manually in the assembly.

I have some reasons why I want to stick with Adjustable parts, as opposed to a Part Family...

Any suggestions?!

Kind regards,
MT

 

[beachcomber]

Hi MT,
I'm not sure if this is how you are doing it but you can't use the distance between 2 planes as the assembly variable, at least in V19.
To get round this, make a new variable in the assembly and in the Formula column make it equal to the distance between the planes. You can then use this variable to get the part adjustment.

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

 

[NZMark]

Hi BC,

Here is, perhaps, a more concise example of the problem:

If you create a part, let's say containing a simple protusion, and make the protusion depth an adjustable variable.

Now add a coincident plane to the end-plane of the protusion.

When you place this part in an assembly, and set a value for the protusion depth, the coincident plane doesn't adjust.

I tried a few variations on this, and they didn't work out. Is there any way to have those part planes react to the adjustable protusion length? (is this related to the instructions in your last post...?)

Kind regards, MT

 

[beachcomber]

I tried a few methods and there does not seem to be a way to get a reference plane to move with the end of the part.
I tried making the protrusion from-to extents and using a plane as the 'to', but it still doesn't move.
Why do you need it?


bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

 

[NZMark]

Hi BC,

Just to reiterate, the problem only occurs in connection with Adjustable Parts (in assemblies), as per the posted graphic above.

(i.e. No problem with maintaining the association of a coincidence plane and a protusion end-plane in a normal part!)

My reason for wanting this (modest?) functionality, is that I have to construct an assembly of adjustable parts, *starting with approximate placeholder ("dummy") parts with simplified geometry*.
Later I will replace these with more complex parts, but with different surface definitions.

So, I would like to initially place the dummy parts using associative relationships, but not using their surfaces for alignment (as these will change upon part replacement), instead using reference planes (which will be maintained between dummy and final parts). This all works with non-adjustable parts.

Hence, I would like reference planes that move with the adjustable dimensions!

Is there something to try in the Part/Assembly Variables List to force the adjustable part to update?

A rather gratuitous example of the ref. plane not moving with adjustable dimensions is as follows (I had thought this would have been a brute force solution!):

- Place a parallel plane in a part.
- In Dynamic Edit, set the displacement of the plane to a variable, and make this adjustable
- Import into Assembly as adjustable, and set adjustable variable
...but ref. parallel plane doesn't respond even to this! (it's still in its "nominal" position).

Any further help would be greatly appreciated. I can provide more screen shots if this would help...

Regards, MT

 

[donyoung]

Hi,

the plane shown in the first posting will not move
just because the modification to the part will be
done within the assembly only. That is the part
itself will not be modified and therefore the plane
(coincident) will not move only the height of the
part will be adjusted -- that's all.
It will work different when you define:

- a parallel plane with distance x (the variable with
that dimension will automatically defined by SE)
- make the part adjustable and use the variable that
holds the dimension.

- in the asm define a variable to control the dimension
- place the part as adjustable
- assign the defined assembly variable to the part's variable
(within the pop-up window)

Now, changing the assembly variable will move the part's
plane and everything that is created on this plane.

@BC
I use Camtasia Studio to create those 'movies'

dy

 

[beachcomber]

Don,
That is what I tried, but the plane still does not move.
My steps were (V19):
In the part file create a plane parallel to one of the base planes.
Give the offset distance a name other than V123 etc.
Create a protrusion FROM the base plane TO the offset plane,
so the distance between the planes controls the protrusion length.
Make the part adjustable, with this distance as the adjustable dimension.
In the assembly create a variable to control the length and assign it to the part plane offset variable.
The length of the protrusion changes, but the plane position does not.
I also tried it using a surface instead of a plane as the protrusion limit, but the result is the same.
I can't understand why the feature controlling the protrusion length does not adjust with the protrusion.

bc.
2.4GHz Core2 Quad, 4GB RAM,
Quadro FX4600.

 

[donyoung]

BC,

hmm, I've just checked it and in fact it will only move
the object on that plane but not the plane itself, I'm
a bit confused because I got it to work as expected at
least once -- maybe it was just by accident/an internal error.
It seems that SE can only adjust objects but not refplanes
whether associated with an object or not. The help does
not have any information on this. BTW: the behaviour has
not changed with V100.

dy