Introducing the Cobra Carriage!

Born out of wanting a carriage that supported a 4010 blower fan, and one that was lightweight, I designed this. The 4010 blower is surprisingly powerful for its size. I think it also runs quieter than the 5015 blowers too. The carriage is designed for the Anet A8, however should work on other 3D printers with 45mm rail spacing (centre to centre) on the X axis.

The Cobra Carriage weighs just 45 grams with no hardware! It measures just 60mm wide by 74mm tall and 66mm deep with all hardware installed!

The fan duct is not great, hopefully someone else who is good at that sort of thing can design one for me. I am having to run the fan at 75% to avoid Thermal runaway triggers.

*** PLEASE NOTE: The initial release is only for 45mm rail spacing. There are TWO versions of the A8 with different spacing. Check before taking the time to print it. I am using it with my Anet A8 X axis redux https://www.thingiverse.com/thing:2814446 ***

*** ALSO NOTE: Due to the positioning of the nozzle with this carriage. It is possible your X axis motor holder and or idler may hit your Z couplers when homing. To avoid this you can print some spacers that go between the bearing blocks and Y carriage. https://www.thingiverse.com/thing:1129055 ***

I suggest supports touching buildplate only with a roof and print the body how it comes in the STL. Block supports from being created in the nut trap and bolt hole else they will be a pain to get out.

If you want to use a 40mm fan (ie Noctua) you could use this adaptor https://www.thingiverse.com/thing:1546165

Print in ABS or PETG. PLA is likely to soften and warp for the fan shroud.

Required Hardware:

1 x M3x30mm Bolt to go through the back of the fan shroud and clamp it to the E3D cold end.
4 x M3x15mm Screw to attach 30mm fan
2 x M3x20mm Bolt to go through E3D clamp into main body - 20 x M3x20mm Cap head on Amazon
2 x M3x10mm Bolt for mounting Bltouch 10 x M3x10mm Cap head on Amazon
5 x M3 Nut. 2 for E3D clamp, 2 for Bltouch mount and 1 for Fan Shroud clamp
4 x M2x5mm Screw to attach 4010 blower and its duct. Screw duct from inside edge, closest to the hot end
3 x igus RJ4JP-01-08 polymer bearings or LM8UU linear bearings 8 x RJ4JP-01-80 on Amazon
1 x E3D V6 or V6 clone Clone E3D v6 on Amazon
1 x 30mm 12v Fan OR 40mm fan using this https://www.thingiverse.com/thing:1759396
1 x 4010 12v Blower Fan 4010 blower on Amazon
1 x Bltouch or 3Dtouch sensor Bltouch on Amazon

Assembly is pretty straight forward. Bolt the fans and sensor to the shroud before installing on the E3D.

You may need to use a flat screwdriver or something like that to pry the slits on the bearing carriers as they are tight to get in.

Belt holder has been designed around a "GT2" belt from ebay.

Offsets:

#define X_PROBE_OFFSET_FROM_EXTRUDER 24

#define Y_PROBE_OFFSET_FROM_EXTRUDER -1

#define Z_PROBE_OFFSET_FROM_EXTRUDER -0.25



#define LEFT_PROBE_BED_POSITION 20

#define RIGHT_PROBE_BED_POSITION 200

#define FRONT_PROBE_BED_POSITION 20

#define BACK_PROBE_BED_POSITION 200



#define X_MIN_POS -28

#define Y_MIN_POS -10

These are ROUGH offsets. If you work out better or more accurate ones please post in comments :) Also take into account I use my "X axis redux" so the endstop position may be different with your set up.

If you like this thing please consider buying me a beer by tipping me.