how do i make the axis on a rotating door horizontal?

i'm trying to make an iris door, but i can't remember how to make the axis for the rotating door horizontal. how do i do so?

First, you have to make a brush that has all sides textured with common/origin, select both that and your door, and make them a func_door together. This way the center of the rotation will be the center of the origin brush.
Now, select any part of your door, hit "n" (entity info) and read:

Normal rotating door entity that opens by rotating around an axis (default: Z). Use an origin brush to specify the rotation axis.

This means that you have to shape the origin brush as if it's the "screw" that the door rotates around. It doesn't have to be circular or anything, just make sure that the dimensions of the brush correlates to the axis you'd like your door to rotate around (longest in eg. X axis = will rotate around X axis).
If you don't set an origin brush, the door will rotate around the Z axis, and will use the center of the door as rotation origin.

well, i'v done that and it isn't working for some reason. i used to be a big map maker in the past, but it was on a mac and it was about 2 years ago. it seems that things aren't working like they used to for some reason

I am actually having issues with this too...

Maybe make the origin brush longer in axis of rotation.

the origin brush is already long in the y direction than it is in x and z.....

longer than the entire door infact