Banner-ad frame, modular

This was a banner-ad frame I created for a local company. Since they had alot of different banners, i made it modular in nature - all the parts in orange and red are welded, all grey parts can be changed, so the frame can be 2x3m or 2x6m, depends on the need. One of the prequisite of this system was that it had to stand on its own. Made out of pretty thick tubing, the 2x3m frame weight came to almost 350kg - no real extra blocks needed to keep it up in the wind. Please let me know if the STEP file works, had some trouble saving it.