Screw (video tutorial)

Hello.

I am still trying to finish my first tutorial for SW.

Now is time  of the screws for the camera.

The problem : The videotutorial shows how to do a screw, using extruded cut.

Then picks "rectngle center" and press at the middle of the circle plane.

He makes first rectangle then repeats the action and does the second one, this time horizontal. Finally picks 1 line from first rectangle and then another line from the secondone and press "equal" inside relations.

Now he can move any side of any rectangle and they are ALWAYS proportional so you can choose any width and the draw mantains the relation,

When I repeat the same process than the video when I move any side of the rectangles ...they don't move equal and the rectangles don't maintain any relations with the center of the circle plane....

I've tryed like 5 times doing exactly the same than the video...and I can't approach any positive result.

Thanks a lot!