Move object from center bidirection

[gary.wuEQ8E4]

I have a drawing that contains two parts. Part A can move left and right based on the center point of Part B. The moving distance must be between -90mm(Top left) and 90mm (Top right). 0mm means Part A is in the center position.

However, I got some trouble creating this movement. It seems I can only create a movement that starts from 0 to a certain number. This means I have to place Part 1 at the top left and set up the max movement is 180mm. That's not the ideal way to do it.

Is there any good method to do a bidirectional move with 1 parameter (value from -90 to 90)?

[j.palmeL29YX]

Something like >>that<<? 

(The embedded video is for my testing only)

[gary.wuEQ8E4]

Hey... Sorry for the late reply.

I was working on your suggestion. It solves the problem. However, it seems the constraint conflicts with my action parameters. The rotation action would cause abnormal activity on the block even after I removed the horizontal constrain and fixed constrain. 

Is there a better solution for this? Or how can I solve the rotation action issue?

[j.palmeL29YX]

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@gary.wuEQ8E4 wrote:

Hey... Sorry for the late reply.

... it seems the constraint conflicts with my action parameters.

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It is always a bad idea to mix constraints and actions in the same block definition and in most cases it will fail. 

In your first post#1 there was no mention of a rotation parameter nor action, so I could not know that. Notwithstanding a few exceptions you should build the functionality of a dynamic block either using only dynamic parameters and actions or using only parametric constraints and dimensions.
If you need further help for your current problem let us know the complete requirements and needed functionality of the block.