Step 2　In the same sketch
Draw a spline and the dimension as provided picture
circular pattern – change the number of instance into 3

Step 3　Insert a new plane(A)
Offset from Top plane and assign an offset value of 150mm

Step 4  Plane(A)
Draw a polygon from sketch entities；set the number side to 3 ；
assign a vertical relation to the side of the triangle

Step 5  Insert a new plane(B)
offset from Plane(A) and assign an offset value of 35mm

Step 6  Plane(B)
Convert entities；select chain

Step 7  Loft
Start / end constraint (Normal to Profile)
Note: three green dots must be placed as provided picture

Step 8  Fillet – 2mm

Step 9  Front Plane
Draw a centerline and assign the length of 150mm；
draw a centre rectangle and change the dimension as provided picture

Step 10  Cut-extrude
Through all-Both；All bodies

Step 11  Top Plane
Draw a Φ30mm circle

Step 12  Cut-extrude – 5mm

Step 13 
Select the blue surface to make a new sketch  

Step 14  Boss-extrude
Draw a Φ15mm circle and assign a extrude value of 5mm

Step 15  Fillet – 0.75mm

Step 16  Shell
Select the blue line；2mm

Step 17  Front Plane
Draw a Φ200mm construction circle；
draw a Φ1mm circle on the circle. Copy 8 circles by circular pattern.

Step 18  Cut-extrude – 14mm

Step 19  Fillet – 0.75mm