Brother_Sven if you carefully place the panel in the top, the edges should be flushed with the tube, a little bit more inside than in the middle, this will help prevent shadows
Brother_Sven mark in the copper tube were there is a hole in the card, if there are none just do .5 cm from the edge of the card, make sure the frame is tight with the tubes fully inside the angles, do this for both sides
Brother_Sven carefully remove the panel and put it in a safe place, the take that copper tube and cut it in the markings
Brother_Sven when you put the frame back it should look something like this, but now its larger and it does not fit, so we need to make it the same size as the top pipe
Brother_Sven take both bottom and top tube and put them together side by side, nicely aligned, then mark where the extra length is
Brother_Sven both top and bottom tubes should be exactly the same length with the two "T" tightly fitted in the bottom
Brother_Sven put the frame back together and now cut some 10cm to 15cm for the bottom two stands, this length is arbitrary and will decide the height, but too high will cause it to be unstable, 10 cm is a good length
Brother_Sven now cut two 30cm pieces from the leftover tube, and then cut it in the middle, so you should have 4 pieces of 15 cm
Brother_Sven put these four 15 cm pieces in the bottom and now your frame is completed, its just needs to be affixed together, but it should look something like this
Brother_Juan Looks good! Steampunk style 🤟 I'll try with the laser cut frame first, if it doesn't work then I'll do this one If it works I'll be posting the files and guide
Brother_Sven Brother_Juan Thank you Brother Juan!, looking forward to seeing your prototypes and to help in any way