quick exercise learn flex and loft command
first step create 2 plane from front plane one must be 150 mm and last one must be -150 mm .
select plane one and create a circle of 17 mm like in image inside it create 5 circles they must be tangent relation each other and also tangent to 17 mm circle.
make the same step on plane 2
after that create a circle of 40 mm on front plane make it for construction
open a sketch on right plane make the same sketch as you can see on the image
and put pierce reation as you can see on the second image. to do that select the circle and the sketch .
create a loft