Dynamic 3D block wonky move/stretch

[donald_vanzwyndregt]

3D dynamic block of suspended pipe support bolted to steel.

Move action with grips works once, second grip move has no visible effect yet the DIM_X or Y property number changes.

Entering the value for DIM_X or DIM_Y works fine.

Perhaps related to the stretch actions used to provide the total length of the steel members?

Note: baseplate dims are locked for this block, I'm only referring to the length and width values.

Thank you in advance for any advice.

[j.palmeL29YX]

Two basic mistakes in your block definition: 

1. Dynamic blocks are for 2D only. 

2. You must not mix Dynamic Parameters/Actions with Constraints.  

It is not possible in AutoCAD to build a block which fullfills all the expected functionality. Only a block with variable Dim_X and Dim_Y may be possible. (Assoziative Surfaces based on a 2D-Sketch in the XY-plane of the block editor). 
But never at the same time you can change the dimensions (diameter and distances) of the holes.

[donald_vanzwyndregt]

Dynamic blocks are for 2d only, okay I get it.

The attached example has a baseplate with variable length and width plus hole distance limited to between 30 and 40mm and hole diameter set to between 20 and 26mm.

It is possible to fake some rather nice 3d dynamic blocks using basic Autocad.

Also, this block is set up the same as the previous example where the move action doesn't seem to work properly but in this case it works fine and I can't find the difference.

Age is catching up with me.

[Washingtonn]

Create steel members from 3DFaces which will stretch within a dynamic blocks.

As for Dynamic Blocks being 2D - this is correct for using the parameters but you can actual get some 3D actions as shown in the following video clip.

[j.palmeL29YX]

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@donald_vanzwyndregt wrote:

I can't find the difference.

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Sorry, I don't understand. I can't see any significant differences and also no different behavior. In both blocks you can change the plates, and in both block you can not chance Dim_X and Dim_Y.

This is, because the plates are driven by "dimensions" which reside in the XY-plane, but the "dimensions" to drive Dim_X/Dim_Y reside in the current XZ-plane. This will never work.

All "dimensions" which shall drive the geometry (parameters/actions or constraints) must reside in the same plane. So you can drive either the plates OR the Dim_X/Dim_Y values.