Hi all,
Today, I finished the rebuild of my K8200. I replaced the standard extruder/hotend with an E3D Kraken.
To get this working, I needed to replace the standard controller board with a RUMBA controller card. This card is capable to control up to three extruders, which make it possible to print in three colors or two colors and a support filament like 1.75mm PVA.
A big advantage of the Rumba card is, that you need to attach two power supplies. One for the heatbed and another one for the extruders/hotends and fans. This way you can connect a power supply with a higher voltage for the heatbed without additional circuits.
The E3D Kraken can only accept the 1.75mm filament via a Bowden extruder so I installed three Airtripper’s Direct Drive Bowden Extruders. You can print and build them yourself or a ready build item is also available via Ebay if I’m correct.
A disadvantage is, that the hotends are placed 20mm from eachother so the maximum usable print space will be a little bit smaller than the original space.
The E3D Kraken has got two connectors for water cooling, so on top of the printer, you see a 1.5 liter water reservoir that is used to cool the three hotends.
To attach the E3D Kraken to the printer, I designed a small adapter.
My Z-axis is still the original one as I never experienced major problems with the axis, but I will replace it once the new K8204 (Z axis upgrade rod en coupler) will be available, because it always can be improved a little bit. Then I will also install a second Z-Axis on the opposite site to further improve it.
In the picture below, you can see my very first trial with dual color printing. The main color was light blue so you can see some traces of the darker silver. I suppose if I used the colors reversed, the result would be slightly better.
Anyway, I still need to experiment with the retraction of the filament to prevent these traces a much as possible , but for my first print in dual color, I’m already very happy. I also need to adjust the amount of filament when the printer starts again with another color because now the first milimeters nothing is printed as the filament doesn’t come out yet due to the retraction.
I also need to adjust the printer settings as now you can see on the result that the spaces are not completely filled. So still a lot of work before the result will be optimal.
Next tests will be triple color or two colors with a support via the third extruder.
