Like many others I have installed a pair of e3d v6s but I thought it might be useful to those who might be thinking of doing so if I outlined my experiences on this project.
My starting point was the file of K8400 parts download on thingiverse which is an amazing resource for k8400 owners, It allowed me to modify the existing mount plate without having to measure it myself. My approach was similar to that of others in basically just attaching a T bar to the front of the mount plate to support the e3d hotends. Where I think I differed was in making this assembly quite deep (12mm) I did this to try to maximize the rigidity of the assembly and because it meant that I not only didn’t lose any movement on the z axis but actually gained a couple of mm…
I retained the top fan but didn’t reinstall the little fan. My first print was a great disappointment and from my limited knowledge I guessed that the problem was cooling. To address this I made small duct for the top fan to direct its output directly on the point of extrusion. This helped but the quality of the print was still poor. I then reinstated the small fan and that improved matters a lot but I was not printing as well as with the original hotends. I then made another duct for the little end and I was careful to ensure that the fan experienced no backpressure by making sure the surface area of the outputs matched that of the output from the fan. This worked well but it means I lost 20mm of the y axis because of the little fan. It also meant that I lost25mm on the x axis because I had had to reorientate the e3d fans from the front to the side which lost me 20mm and the hotends are wider than the original ones which lost me another 5mm.
I now wondered whether the top fan was actually necessary so I disconnected it and found no drop in quality. So I shortened the mount I had made by 20mm and everything worked fine. So now in comparison with the original print area of 180 by 200mm I had 180 by 175mm and I don’t see anyway that I can retrieve the lost 25mm on the axis but I can live with that,
I still had one problem and that was matching the height of the two nozzles. Every version I built always had the left extruder nozzle 0.15mm lower than the right hand one. I had overcome this problem by inserting layers of 0.8mm plastic sheet on the left hand side between the mount I hade made and the ‘XY carriage 2’. While this worked it was crude and its accuracy was restricted to the thickness of the plastic, i.e., I could only go in steps of 0.8mm.
To address this problem I decided to use screws to adjust the height,. To this end I made little inserts to fit into the gaps on the top of the ‘XY carriage 2’ without increasing it height. These inserts are what my screws would push against.
My previous mount had a gap in the centre exactly the same as the original mount where the top fan sat. I filled this area and on each side made two 3mm holes to take 3mm cap screws and a hexagon recess at the bottom to hold the nut,
To test this arrangement I reassembled everything and made sure that bed was level. I then sent the extruders to the home position and then moved them to the centre. I measured the gap between each nozzle and the bed and found as usual that the left extruder was 0.15mm lower. Now the pitch on the 3mm threads I was using was 0.5mm so to raise the extruder by 0.15mm required that the screws be turned 108 degrees. I lowered the bed slackened of the four screws a holding the print head assembly together by a couple of turns, turned the left hand pair of adjusting screw approximately 108 degrees, tightened the pair of right screws holding the assembly first and then the left ones. When I came to measure the gaps between the nozzles and the bed they were to all intense and purpose identical.
I am going to do one further thing which is again to use the K8400 parts download to get the stl file for the bottom xy carriage support and modify it by adding recesses to hold the nuts. By doing this I won’t even have to lower the bed to match the heights as I will be able to do it all from the top.
Hope this is of some use to those thinking of fitting e3ds’ and I would be interested to hear others solutions.