I'm trying to create a dynamic block for wiring connections of our field parts. The wire is intended to represent a "Twisted Pair" communication cable, so there is what I'll call a "Wave" in the middle of the block. There are two (2) line segments on each side of the Wave.

I want to Stretch the line segments on both sides of the Wave in one direction but I want the wave to stay in the center of the block.

I'm able to get the lines on both sides of the wave to stretch correctly, and able to keep the wave in the middle of the line block.

My problem is that the grip should remain at the end of one of the stretch parameters, but it's not. I suspect it's not because my Move parameter isn't moving the line segments on the right side of the wave in the block.

I can't figure out how make the grip track with one side of the block when it's being stretched?

uploads/290750/Dynamic_Wire_Stretch.dwg