A dual extruder mounting system for a Bowden feed tube setup on a Prusa i3 with multiple versions:

• One with an 8mm Z offset (V2).
• One without any offset (V4).
• One with a 6.5mm Z offset (V5).

The clamp will securely hold any of the groove mount extruders (16mm/12mm/16mm) such as the E3D and J-Head Style extruders with one M4 nut & bolt.

The V2 files are designed to hold one of the old style Ebay J-Head Extruders from China which is (mine is anyway) 8mm taller than the new and shorter E3D V6 extruders. You should definitely check your Z Offset before printing these files as I'm sure there are many variations out there.

The V4 files have no offset and are for mounting two extruders which are both the same height.

The V5 files have a 6.5mm offset on the left Extruder. It incorporates the improvements made in length and slight improvements in extruder spacing (moved 2mm closer).

The part was written to try and ensure that the extruders remain as true to center as possible however there is a slight offset as I needed to take into account that the old style J-Head has a slightly larger diameter heat-sink (and cooling fan mount).

V2 Specs:
Backing Plate Dimensions: 44.5mm (W) x 44.5mm (H) x 6mm (D)
Neck Overall Length: 35mm measured from the center point of the extruders
Neck Thickness(Z Height): 12mm
Overall Y Offset: 41mm measured from the center point of the extruders
Nut/Bolt Dimensions: M4 - a large range of Bolt lengths are accommodated

Left Extruder Z Offset: 8mm
Left Extruder Fan Housing Clearance: 35mm total half this from the center of the extruder
Right Extruder Fan Housing Clearance: 30mm as above
Clamping Collar Thinnest Wall Thickness: 6mm

V3 Specs
All specs are the same as above apart from having only 30mm clearance around each extruder (that is approx. 15mm radius from the center of each extruder). These have been removed and replaced by the improved V4 files.

V4 Specs
30mm clearance around each extruder (radius = 15mm from the center). I have updated these files (from the V3 specs) for a better fit onto the backing mount for less post print work and increased the step out (neck length) slightly to better utilize the print bed area along the Y axis. There is also a slight increase in the diameter that is cut out for each of the bolt holes.

V5 Specs
Please see the notes above.