This 4 prompt Fast Load AutoLISP (FAS) application, lets you build a complete 3D helical ramp, including sidewalls, landing bridge and center shaft.
Just specify : Height per revolution, landing height, inner radius and ramp width. You'll watch the ramp being built in seconds performing the following tasks: ramp, exterior sidewall, interior sidewall and landing bridge as separate solid elements. You can erase the ones you don't need.A center shaft can also be constructed by typing “shaft” at the command prompt.