Derived from the design of thing 17965 by dmeehl. I haven't been able to find a good mount for my Printrbot+ LC but dmeehl's was close just not quite long enough because it was designed for a different printer. I mocked it up in Tinkercad and made it a bit longer so that it should fit my laser cut extruder.
The original design ended up not working too well in practice, it bent too much but it might work in ABS better so I will leave it on the model. For v2 I basically redesigned it from scratch to be much simpler and more stable. v2 is the one I am using on my Printrbot now and it seems to be working well.
This is designed for my Printrbot+ LC but I believe most of the Printrbots use the same or similar extruder design and this is basic enough to work with a bit of tolerance. Leave some comments if it you have a different model and let me know how this thing works.