I designed my own truss system :-)
A section is about 25 cm in height, and the heart-to-heart distance between 2 outer poles is 15 cm.
You need long pieces of rod, 10mm diameter.
Yellow pieces can be connected with M3 bolts/nuts ...

I'm using this system for my homebuilt large RGB LED matrix. (2m x 1m20, so 320 x 192 pixels)

I still need to draw the corner pieces. Give me some time to finish this :-)

• I use pieces of 2 meter 10mm hollow aluminium rod.
• you need 6 M3 bolts/nuts to connect to sections together.
• Cut 3x 26,5 cm rod for the diagonal parts.
• leave the 3 vertical rods in one piece, just slide your sections over it.
• Use 2 identical parts for every section.
• Alternate between regular and mirror part for every section.