Depending on how consistent extrusion is for the object you are printing, you don’t need to modify the 2.75mm hotend for 1.75mm. I recommend getting a hotend/nozzle or printcore with a 1.75mm-2mm inner diameter to reduce the filament play in the print head to avoid clogs. I converted my Ultimaker 1.75 with the DXU printhead that you can get more info for at github.com/ansonl/DXU
Is this all you had to do to print with 1.75mm or did you modify the printcore also?
Depending on how consistent extrusion is for the object you are printing, you don’t need to modify the 2.75mm hotend for 1.75mm. I recommend getting a hotend/nozzle or printcore with a 1.75mm-2mm inner diameter to reduce the filament play in the print head to avoid clogs.
I converted my Ultimaker 1.75 with the DXU printhead that you can get more info for at github.com/ansonl/DXU