create 3d curve or helix

Question

Hi all 
 I need to create a ramp between c-c' en d-d'. Same for a-a' and b-b'. To take on example: the radius on c-c' = 325 cm en the height is 350 cm. But the angle between c and c' = 227.8652&deg;. See image below. 
 How to create this 3d curve or helix? 
 
 Best regards, 
 Jean Castro

Ron Jones · Accepted Answer

Hi Jean, You can can use Surface by Extrusion Along. Key-in: CONSTRUCT SURFACE ALONG 
 Just draw your 350 cm vertical axis and line C-D, and set the spin angle to 227.8652. Now extrude line C-D along the vertical axis. Cheers, Ron

Jon Summers · Answer

Unknown said: How to create this 3d curve or helix? 
 Type helix into MicroStation's help Search tab to see several answers. 
 You can create a helical curve, surface or feature. Key-ins: 
 
 CONSTRUCT SURFACE HELICALSURFACE 
 PLACE HELIX 
 MODELER HELIX

TSL · Answer

Thanks Ron and Jon for replying my question. 
I could create my two ramps with the keyin from Ron.