Thought I wopuld share this transition as it came out pretty good.
I needed a transition for my blower. I wasnt happy with the Borg bought "register" type so I decided to make a custom fitted evolution.
I used a spread sheet calculator to determine the bends to transition form a 5-1/2"x7" rectangle to a 6-1/8" dia circle. (You can find a link for the calculator somewhere on Bill Pentz's website)
I plotted out a full scale template of the transition then transfered the shape to a 16gua sheet of galv steel.
Most of the tools for cutting
cutting it out
I taped it down to the sheet of galv steel so I could trace the shape
tracing the shape
I used a nail to mark the end and start of the lines.
my shape is done
connect the dents
I cut the sheet so I could trim the shape better.