Strut Attachment in Making History

[Salokin9]

In to the Mun Via Minmus, the ship has two cores. One is attached by what looks like only struts. Can anyone explain how to build something like this? 

https://imgur.com/hMv8n7f

https://imgur.com/a/bkOEb

 

 

Edited March 22, 2018 by Salokin9
Added image

[HvP]

I'm guessing that the lower central portion was first attached to the bottom of the upper half normally (the small white separator was attached to the small inline battery above it.) By selecting the "translate" gizmo you can click the lower part, hold shift, then slide it downwards to open up a gap. Then then you can attach struts between them to make it appear that the struts are holding it together.

Once you've done this you can place the other surface attachable parts, like science experiments and RCS thrusters anywhere you want. You wouldn't be able to attach any center node attached parts in the gap between the two sections however because those nodes are technically being used to hold the ship together even though cosmetically there is a gap.

Edited March 22, 2018 by HvP