Friction stir welding - GIF, video, and images

[Jon]

Are they intentionally friction drilling the hole to build up the hole walls, so that they can then insert a threaded insert into the hole, such that the insert will have more support on its perimeter?

[Toolmaker51]

Not in the GIF version, but could be done. Isn't any 'flash' remaining around the insert, a PITA to remove, doubly pointless application of thermal drilling. Rim of insert protrudes above parent metal. Thermal drilling [ferrous] in a wall thickness ~ .5 diameter creates a topside depression somewhat like a countersink; in most cases, a beneficial feature.
IMHO insert is in a standard drill hole, versus tapping a thermal drilled hole. Can't justify why the GIF shows two thermal-drilled holes. Mayhaps I'll re-visit GIF and re-evaluate.
My 'edit' button hasn't worn out yet!
Insert GIF, thermal drill has a head to roll the upper perimeter into a rim. But the flash below isn't visible, just the insert.
And still, 'edit' button hasn't worn out.

[Jon]

Aluminum stir welding.

[Ralphxyz]

Just how is that motor working? Is the motor and wiring on the other side?

Ralph