3DS Cube 3 Replacement Filament Feed System "HubCap"

Do you have a 3D systems cube that has soul crushing print failures?

Often the cause for print failures is old and brittle 3DS filament that breaks in the feed path when being fed into the top nozzle. The default 3DS system puts a lot flexing stress on the filament and the feed tubing is fragile usually leading to clogs and print failures.

This is a "bowden" PTFE tube assembly replacement that is intended to limit the amount of flex and reduce friction on the filament as it is fed into the extruder. With the help of the 3DS filament "hack" non 3DS filament can also be used.

http://www.print3dforum.com/showthread.php/900-Cube3-Filament-*SOFTWARE*-Hack-is-here!!!

The "HubCap" can be used without the "HubClip" by the installed magnets. The "HubClip" will clip in-place to add extra security, is designed to help channel the stepper cooling fan air to the metal extruder housing and provides a filament feed guide. TO remove the Hubclip, simply pull straight off.

This "kit" consists of 4 separate 3D printed parts. It also uses several parts from the stock 3DS filament cartridge.

The additional parts needed are:

3DS Cube metal extruder housing, HOBB bearings and screws etc.
3DS Cube metal nozzle tip
3DS Cube nozzle spring
3DS Cube 3mm PTFE tub3
3DS Cube Filament Chip from cartridge housing.
PTFE Teflon tubing 2mm ID 4mm OD https://www.captubes.com/shop/#!/1-Meter-Low-Friction-Bowden-Tubing/p/82190682/category=23214267
2x M6 Pneumatic quick fittings. https://www.captubes.com/shop/#!/4-Pack-PC4-M6-Fittings/p/84203147/category=25823850
M6 thread tap (matching the pneumatic fittings you are using) https://www.amazon.com/gp/product/B071VKZ2DC/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
2x 8mm wide 3mm thick Neodymium Disc Magnets https://www.homedepot.com/p/MASTER-MAGNETICS-0-3-in-x-0-11-in-Neodymium-Rare-Earth-Magnet-Discs-10-per-Pack-07045HD/202526363

WARNING:

The purpose of this was to get my cube printing again at 70nm without filament failure, the stock parts were simply not working at all.

However the fix has a few potentially frustrating aspects.

1. The filament needs to be loaded by turning the hobb-gear with a screw driver. The filament tends to get curled by the gear so initially feeding filament past the extruder into the PTFE tube may take several tries. I found it best to have the filament cut at an angle to help the end slip past the small inner edge between the extruder and pneumatic quick fitting. Once loaded, I tend not to change the filament often.

2. The "HubClip" is intended to be as simple as possible to print. The clip section that inserts into the cube printer can be fragile depending upon the material printed and settings used. I use ABS, as I found PLA to be less flexible. The clip can be hard to remove, but I simply pull it straight off or use a flat head screw diver to ply it loose on one side first.

3. Be careful when installing and removing the printed head, it is best to wait until it has cooled off to make any adjustments. Polycarbonate is more resistent to heat compared to PLA and ABS.

Big thanks to the members on 3Dprintforum.com in particular TommyDee, MegaloDon, bolsoncerrado, Mythandar, and ztoddman1

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