Filament Guide Assembly

This is the top-level page for the assembly which supports the Filament Guide 2 and the Extruder Bundle Strain Relief mods.

There are three components needed for the assembly:

You'll find the STL models for each from the links above.

The full assembly was designed for a height and depth which produces a smooth curve in the filament  as it unwinds from the spool. Its purpose is to enable the filament to play out evenly (ignoring retractions...) with no friction between the filament and any surface (except for a small wiper cloth if desired , as seen in Figs. 8 and 9 below).

f3d filamentguideasm

The Filament Guide 2 mod is designed for 1.75 mm filament only!

The models for these mods are sourced as components in the large Ender 3 Subassembly model (and must be downloaded from there).

This mod requires a small amount of hardware:

Quan Desc
1 M4x20 fastener
1 M4 hex nut
4 M4x12 fastener
4 M4 hex nut
1 22 mm diameter roller


20181102 091423Fig. 1

Shown here are the printed components along with other hardware needed:



20181102 091050Fig. 2

Right side view full printed assembly less the roller.


20181102 091011Fig. 3

Left side view full printed assembly less the roller.

Note the bosses which contact the roller's ball bearing inner race and ensure that the roller is enabled to rotate freely without any friction against the side walls.


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Fig. 4

Bottom view full printed assembly less the roller.


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Fig. 5

Right side view full assembly, mounted in place.


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Fig. 6

Left side view full assembly, mounted in place. The Extruder Bundle Strain Relief is also in view with zip ties securing it in place.


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Fig. 7

Bottom side view full assembly, mounted in place on Z-axis roller fastener. The extruder bundle strain reliet is also in view with zip ties securing it in place.


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Fig. 8

The filament guide provides a pocket in which a small wiper cloth can be inserted. (See Fig. 9.)


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Fig. 9

A close-up of the pocket for the wiper cloth (See Fig. 8).

Note the two small flanges at the rear of the channel to hold the wiper cloth in place.

I designed the Filament Guide to move the filament slightly (~0.5mm) toward the rear of the printer to ensure that it does not contact the Z lead screw.

IMO, the location of the Z lead screw relative to the axis of the filament through the extruder stepper motor appears to be poorly envisioned. The bracket which holds the extruder stepper motor could have been made about 2 mm deeper (toward the rear of the printer). I can only assume that something was overlooked or changed after the design was largely committed for manufacture.


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Fig. 10

Close-up of the Extruder Bundle Strain Relief (below the Filament Guide Base) with the rectangular slots provided for the zip ties. (Bundle currently not secured to provide a good view.)


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Fig. 11

A close-up of the support flanges on the right side of the Filament Guide Base. These were added for rigidity in the vertical direction.