Man-Machine Interface, where to find respawning targets?

[Tilarta]

I am working on the GRA 3 Star Achievement Man-Machine Interface.

All the notes I have found said that the Mr Steels in New Vegas Steel are the best subjects, as they respawn every 3 days.
But so far, they have not.

Where else can I find respawning targets for this challenge?

And do not suggest any locations where the enemies do not respawn, as I've been through all of them now, rendering them invalid for this challenge as the enemies have already been defeated.

Also, do not suggest allied Mr Gutsy as the target, such as the ones occupying Nellis AFB.
The Boomers (who are allies) would not approve of destroying their robots.....

[Incunabulum]

1. Most cells respawn in *30* days, not 3.

2. You must ensure that you are not in the cell and far enough away that it gets unloaded from memory. So camping righ outside the door won't help.

[Dosbilliam, Boring but Practical]

http://fallout.gamepedia.com/Man-Machine_Interface

[Tilarta]

Most of the above from that link do not count, as they do not respawn (I already deactivated them) or they are Allied.

[Dosbilliam, Boring but Practical]

Allied doesn't matter as long as you can use stealth effectively.

[Tilarta]

It looks like the Steel Gutsy are finally respawning.
I wonder what was blocking them before.

And it's the principle of the thing, I don't like to destroy assets (the Nellis Gutsy detachment) that are being used to aid me (they're maintaining the Volare, amongst other duties).

[Dosbilliam, Boring but Practical]

Originally posted by Tilarta:

It looks like the Steel Gutsy are finally respawning.
I wonder what was blocking them before.

It might have been the cell needed reloading, or you waiting a couple hours less than you needed to. :P