MOD 3 way base connector

Use with mod inner connector SHORT.
Use with MOD 2 way angled connector to create the frame for a light...or something else?
** This is part of a project i'm doing for uni. The concept is all about re-using old/scrap materials. I've designed a series of connectors that aim to join old scrap pieces into new furniture/homewares.
The idea is that scrap material can be slotted into the inner connector (the diameter of the hole can be changed) and then these connectors slotted into the housin