Last year, I bought a 3D printer, and found myself having to make many small objects sequentially for customers' production runs. So, I had to come up with a way to clear the build plate. So, I did! It's been a year, so I'm going to open the design.
It needs to be cheap, easy to build, and adaptable to many printer types. And ideally quieter than the prototype since the idea is to print things overnight and I don't think everyone has their printers in a closet!
I did! The problem problem with those is that they are hard to build, large (they eat up a lot of Z axis build area) and prone to breaking. And you can't really add one to a printer AFTER you bought the printer. This is intended for adding onto an existing printer, same as my L-Cheapo laser cutter.
Won't the prints stick to the surface? I usually see people use utility knives to get them off.
MakerBot made a conveyor belt build platform a few years ago and then made a 3D printer with one built in (the Thing-O-Matic); you might want to look at those.