I know starting collars are to tap off of square duct but is there such a thing for round metal duct. The reason I am asking is because I have a 12 inch supply that I want to take run some duct lines off of. I see that A saddle is about the only thing used for this. I can't seem to find any pre-made saddles around here and all the sheet metal shops in my area are backed up for over a week. Are there Any alternative that don't include seperating the line and adding a tee.
I attempted making the style in the picture below. It didn't turn out as good as I would like and it took a lot of time cosidering I need 6 of them. Is there an easier style to make and if so how is it attached?