E3D dual head on Velleman VERTEX K8400 with space gain and light

Update 19-Mar-2017 New and improved revision of the printhead is available from here.

This set of things allows to upgrade Velleman VERTEX K8400 printer with single- or dual-head E3D hot-end.

Almost all other designs that "marry" K8400 with E3D are reducing print area because of 2 reasons:
- new hot-end is bigger than the original and
- the fans hanging on E3D heat-sinks take a lot of side or front space.

My design allows to attach E3D hot-end(s) to K8400 and gain extra print space