I have that exact adapter and it works fine. Had a laugh at the name, though. SHNITPWR. For when you need an adapter that’s a real piece of SHNIT.
Recently, Amazon search results are cluttered with Chinese brands you’ve never heard of that just sound like some combination of consonants and vowels with no attempt to make an English or even Mandarin word. The important thing is whether the brand can be trademarked and uniqueness matters. Here is a gift link to a New York Times article on the phenomenon.
OP here — status update. After getting a 12v geared motor, power adapter and a cheap display turntable, I’m leaning toward AC synchronous motors. @Dr.Strangelove linked to something similar.
The big reason is they are described (in Amazon listings and elsewhere) as being for “continuous” use. Some of the 12v motors recommend breaks after 5, 10, or 30 minutes. Most don’t discuss service duty.
So, the DC motors would need interval timers. Some of the AC motors come complete with power cords and connection hardware — so, simpler and lower overall cost. User reviews say AC synchronous motors get hot in operation, so design caution will be needed.
@engineer_comp_geek — I also ordered some cute little synchronous teardrop motors from the Science Surplus place. Cheap and fun-looking but not as plug and play.
Sounds like a job for LEGO Technic to me, but only because I already own the bricks.
So you want a DC motor? There’s a big surprise…