Please note I have since changed my printer to linear rails with a different mount so I won't be updating this further, the link to the CAD file has been provided so that anyone may make changes they wish to and remix the design.
This design took some references from the following designs/designers and built upon them to create a setup that suits my printer hardware needs but likely suits many others.
Nase00 - for the nutsert adapter on the front https://www.thingiverse.com/thing:4010707
ChipCE- For the backing plate https://www.thingiverse.com/thing:4017555
PermaNoob - Fan duct - https://www.thingiverse.com/thing:4031637
Prusa - the fan mount is based on their 45 angled blower fan mount but adapted is to suit a Volcano Heaterblock and nozzle. there is also a V6 block and nozzle version included.
For those who wish to modify this themselves I have made the related files public documents in Onshape. where you should be able to copy the document and continue working on your own version.
I am yet to print and try this but will update when I have it installed.
Included in the photos is a screenshot of how to orientate the parts for printing and where supports should be.
https://cad.onshape.com/documents/f04494c9cf5309403af27db7/w/45f1748992e65746c9627977/e/7b9dff52ba52b2a5290a11efthe Probe XY offset is: X:65mm Y:0mm
Please note to fit the prusa 45 angled fan mount using a V6 block I had to cut away some sections of the fan by 2mm to give a 2mm clearance to the heaterblock. I am unable to test if this is sufficient clearance, please make sure it fits ok and does not melt or get too hot. If there are issues i can make changes to the V6 mount design, but I personally use a Volcano.
Also added another fan duct design that integrates into the front accessories holder, the fan mount hole is to suit an M3 Brass Heat set insert. PRINT SETTINGS!!!!
Using prusa slicer under print settings --> Layers Perimetres check the box "Extra Perimetres if needed, and deselect "Detect thin walls" with the main accessories mount/fan duct I've had to remesh the file and am having some strange holes, but if you use these settings it will print perfectly.
GENERAL HEMERA NOTES:
Prusa slicer default retraction if based of the MK3 printer is 2mm, you need to drop this to 1.2mm or (1-1.8mm) and 40mm retraction speed I found 2mm was causing jams and grinding issues and under extrusion at least with the volcano.
UPDATE: 11/12/19 - added an EZABL Pro mount that provides easier access hopefully to the side adjustment screw, this design will have the locking nuts placed lower on the probe so that hopefully you can access adjustment screw whilst probe is fixed in place. Also revised the Main duct/accessories mount for the Volcano(R2) so that there is a slot for the nut on the back incase you cant use a brass heat set insert, also increased hole diametre to 3.3 for better clearance also removed extra material that blocked side view of the hemera heatsink.
9/12/19 - Made the fan mount a little stronger and set it back a bit further from heaterblock on volcano model, as somehow cad model of heater block was not accurate. other than than all assembled well, just a bit fiddly to get the bolts into the square nuts on the hemera motor.
9/12/19 - Added another fan duct design that integrates 'Permanoob's' design into the front accessories mount and uses an M3 Brass heat set insert. Also Revision the mounting plate to trigger more reliably on the X axis switch and to not affect the home offsets.