help extruding along path
 

hi. im new to maya.

I am looking to extrude a profile shape along a path as one might describe that volume that a switchback fire stair might occupy - for example it must main constant sectional dimensions, and I would like for it to have square edges.

I have tried two different routes to get what I am looking for and neither one quite works. FIrst, I tried extruding along a path. While the extusion is close, i am finding that the section is slowly rotating along the path's length. I dont know how to get it to stop doing that.

The other route I tried was to attach the section shape to the path as a motion shape, and then creating an animated sweep. This one works excepts for the corners in plan. When the path turns a corner, I get a step before the corner and after the corner, and ultimately a chamfer between either edge. I have tweaked all the settings I can find to try and force a step immediately at the corner, but I havent figured it out. Even if I were to get one, I am not sure that it would understand how to deal with the sections immediately before and after.

what I am looking for is similar to the sweep command in 3d studio max....but in maya.
see attached screengrab to decipher what I am describing.

thanks in advance