Dynamic Block Action Stretch Question

[kcharette1961]

I have a DI-3C structure that I want to stretch to specific throat lengths.

I want hold the stretch from front mid point of the line with the lookup for throat lengths.

I'm not getting where to do my first corner of stretch frame.

[steven-g]

Take a look at the attached block, it is a very simple example, click on various things in the block editor and take a look in the properties palette to see how it is set up, clicking on the action icons will highlight the stretch frames. Click on the linear parameter and check the properties. Hopefully this will point you in which way to go

Stretch.dwg

[kcharette1961]

Thanks a lot.