Maybe a bottom bracket wrap around template similar to the miter templates to locate the vent holes and or the tube interface shapes.
Wed, Jan 24, 2018
#1
Bottom bracket template for vent holes
A template for the tube interface shape is a good idea that I will consider for a future update. As for the vent holes, the center of the chain stay where it intersects the bottom bracket shell is located by the input dimension F in the chain stay dialog box. Therefore, you can locate the vent holes simply by measuring a distance F from the outside edges of the BB shell.