Terrific Technology

If you use up all the charges on your Engineering item, a new one will respawn in your Garrison building. Since you need to use them multiple times for the achievement, the fastest way you could get this is by chain using the items over and over in your Garrison and picking up a new one.

20 [item=119158]
50 [item=114974]
10 [item=114246]
10 [item=114744]
5 [item=115530]
50 [item=114983]
50 [item=114924]
10 [item=114244]
5 [item=114633]

If you want to smash out your 10 [item=114246], stand in the doorway to the Gearworks - on the small speedbump/hump in the doorway. This is counted as outside, but has the ceiling above you so you won't rocket away. Do this twice to finish the item in your bag, go and collect it again, rinse and repeat.

So, after a year of having my engineer alt at 100 and just using him as a bank/auctioneer toon, I JUST NOW realized that this comes from a large-plot building called Goblin/Gnome Workshop and NOT the Engineering Works small profession building. So don't feel stupid if you've been getting stuck trying to figure out how to get the achieve done on your Engineering Works building.