Hot Glue Gun Extruder 3DP Experiment

Another 3D printing experiment appeared on Hack A Day, in which a common workshop hot glue gun was persuaded to act as an extruder for a hobby 3D printer. 
 
At first this might make sense, as the hot glue gun does extrude material that solidifies. However, after watching the video and thinking about it, we believe this is probably not a terrific way to extrude. While it might be less expensive to make, there are issues: 
 
  • The extruded "glue" seems to slump considerably, meaning rough surfaces and likely difficulties in printing even slight overhangs
  • The glue feeder is limited in capacity to the size of standard glue sticks. Ok for small prints, but anything large would be tricky, unless you build an "auto-feeder"
  • It's really slow. Large prints would take a very long time to complete
 
But now we know, thanks to an idea and an experiment.