Ok but I need to rotate a Cement Mixer on a Cement Truck, the cement mixer needs to be animated rotating, but because a cement mixer is rotated a little bit I can't seem to rotate it without moving the object as a whole. Really all I need to do is rotate it without moving any geometry, or making the geometry rotate along it's own edges. I can't seem to make anything work though. Because the Cement mixer is rotated on the Y axis I can't seem to make it rotate on the X Axis perfectly.
I think I understand, one quick solution (that I don´t recommend) is that you just change the "transformation orientation" (in the top center in the standard layout) to "normal" and now if you press "r" and then "x" you will rotate around the objects x axis. A better solution is to ad an "empty" and set it to be the parent oft the cement mixer. Make the "y" rotation on the empty and then the "x" rotation and animation on the cement mixer. See 4:27 in the video to get an better understanding. Hope this helped otherwise ask again :)
You could ad an “empty” and then select the wrench and then the empty, press Ctrl+p, (to set the empty as the parent) then rotate the empty. Hope that helps
