[blakeyrat]

The gun fires straight ahead. The electrons it produces are deflected in the desired direction by electromagnets.

I don't think it's possible to create a mechanical way of moving the gun fast enough to achieve the needs of even a low-res TV screen. If it was a physical mechanism, you can imagine it'd break all the time.

[schwap]

Not to mention your TV would sound like it was possessed by a banshee from the servo (presumably) noise.

[mchanson]

There was such a thing as a mechanical television:

https://en.wikipedia.org/wiki/Mechanical_television

[blakeyrat]

Not one using an electron gun. The article is specifically about CRTs. (Of course I know about mechanical televisions; I just didn't talk about them because they weren't relevant to the topic.)