@NorthShore, what type of nuts are you using?
Are you using keps-nuts (pictured below) or regular nuts (without the spiky collar)?
For different places on the robot there are different mounting options that work the best.
If you are attaching two aluminium pieces together, then properly tightened keps-nuts are the best option.
If you are attaching plastic bearing block to a metal frame then it is best to use nylocks:
And, if you are using standoffs, instead of nuts, then it is best to insert plastic spacers between the metal and standoff that could compress:
In my experience, using thread-locker only makes sense when the joint is experiencing constant twisting loads. Then use only blue (medium strength), because once you apply red (max strength) thread locker, you could only undo it with a heat gun.
Screws with pre-applied thread locker (blue dots) are usually much more expensive and it is cheaper to apply it yourself. But, once again, most of the times nylocks are all you need.
Additional info could be found here: Standoffs Coming Loose - #11 by technik3k