I put together a list of 3d printers featuring some form of automatic ejection.
If you know of a printer missing from this list please submit a link using this form.

Company

Quality

Technology

Cost

link

⭐⭐⭐⭐⭐

Disposable build surface film on roll with vacuum plate.

$100,000+

https://www.stratasys.com/3d-printers/continuous-build-3d-printer

⭐⭐⭐⭐

$11,000

https://blackbelt-3d.com/blackbelt-3d-printer-desktop-version

⭐⭐⭐⭐

Bulldozer sweeps build surface to eject part.

 

$23,500

https://visionminer.com/products/saam-ht

https://www.e-ci.com/saam-ht

⭐⭐⭐

Stationary blade with moving bed.

$3,000

https://autodrop3d.com/