A modification which will allow Robox users to print with flexible filaments such as Ninjaflex. Bowden tube printers struggle with flex materials but the patented needle valves on Robox give excellent results.
In future we will produce extruders with this part as standard, this mod is for reference only. We are working on the details of an upgrade service which when purchased will allow your Robox to be updated with the latest available parts.
WARNING! This mod is not supported by CEL or it’s resellers, any changes to your Robox or changes which affect it will not be covered by warranty.
WARNING! Never remove or connect any plugs or covers while power is supplied to Robox via the mains plug or by USB.
This mod prevents flexible filament (tested with Ninjaflex) from distorting in the gears of the extruder. Details of the mod are deliberately sparse as this should only be attempted by skilled people familiar with the required tools and with Robox.
Do not open any casing or remove any cables while power is present. Leaving Robox completely unplugged – including USB and mains cables – for at least 30 mins will allow capacitors to discharge and reduce the chance of a shock.
It requires printing of the small part shown above (flex_material_part.stl – print some spares before removing your extruder) which fits between the 2 filament drive wheels without stopping the filament from being driven by these wheels. To fit the part some of the extruder housing needs to be cut away from 2 parts of the extruder housing.
Above: Top part is modified, bottom is original.
Below: It is very important that the filament is not trapped by the new part. Use a piece of filament put through the central hole to keep the new part in place while marking prior to cutting.
The depth of the cut is equal on each side. Take care to keep cuts square and neat, we used a grinder similar to a Dremel.
Remove small amounts of material and test the assembly often to ensure the fit is good.
Images below left for reference.