STP-42D201-37 Bipolar Stepper Motor, 12V, 18" Lead Wires, 1.8 Step Angle, 1.65" Dia x 1.49" D

So far so good. It looks well made. She has some gravity in her. I can feel the steps when I turn the rotor with my hand. I haven't plugged it in, but it looks legit.I'm buying this with the intent to do direct drive, shaft-to-shaft. The gear looked problematic for that. I'm still considering this motor because the specs+datasheet look good for what I'm doing, and it's $5, which is great.I can confirm that the gear exists and is on there pretty solidly. It might be an interference fit or similar. If you pull on it hard enough to extricate the gear, you might ruin the innards.However.Note that the gear mates fairly well with a 12mm 12-point socket. It does not seem to play well with SAE though, as 7/16 was too small (idk, maybe if you hammered it in or used thermal interference, but it wasn't going in at room temps) and 1/2 was too big (lotsa slippage; rarely grabbed). So just use 12mm metric (and 12-point! that's important!).This is probably not the cheapest way to connect a shaft. And given that this thing is a rather affordable $5 right now, cost might be on your mind. But at the very least, you can probably find a way to adapt this in a pinch.Disclaimer: I haven't actually ran this motor yet. I intend to use custom circuitry to drive it, so I still have work to do before any testing happens. I bought it ahead of time to test mechanical fit, and here we are.