Filament assist drives make printing tacky, flexible filaments possible by counteracting friction in the guide tube. They also make loading filament easier.

Mechanical assembly:

1. Unload filament and slide the PTFE out of the filament cabinet
2. Using 2x M5x8 screws, attach the mounting bracket to 2x T-nuts and slide the assembly into the extrusion. (If you are installing the assist between two existing positions, you can insert the T-nuts into the channel from the front, then mount the bracket to them)
3. Slide the drive unit until the extruder is aligned with the filament cabinet outlet and tighten the M6 screws
4. Insert the PTFE guide tube into the bottom of the drive unit, making sure the "V" of the PTFE is aligned between the drive roller and idler
5. Insert the upper PTFE guide through the filament cabinet outlet and into the top of the drive extruder, again ensuring PTFE rotation is correct with respect to the drive roller and idler

Electrically wiring:

1. The first filament assist drive you install requires the Filament Assist (FA) PCB. Subsequent drives do not require an additional PCB. The FA PCB should be mounted to the upper position on the front plate of the cabinet with 4x M3x6 screws.

2. Two cables must be attached:
   • A 4-wire cable from MOT IN on the FA PCB to E9 on the Duex5 PCB
   • A 5-wire cable from SELECT on the FA PCB to a cable labelled "Efasw" (not on a PCB)

3. Connect one end of the cable to the correct position on the Filament Assist PCB mounted to the front wall of the Electronics Cabinet. The positions are labelled 1, 2, 3, 4, and 5 to correspond with those tool numbers. The filament spools are ordered 1-5 from front to back. If you are adding a filament assist to Tool 2, you will connect the cable to position "2" on the filament assist PCB, and route the cable back to the second bay from the front in the filament rack/cabinet. 
4. Route the cable through the feedthru hole between cabinets, underneath the trunnion supports, and through the external cabinet feedthru nearest the drive that you already installed. Plug the cable into the drive motor.

To enable the filament assist in the firmware, go to the System Editor tab under Settings and find the tcreate#.g file (# is the Tool position that the filament assist is being added to). Open it up and make sure that the following line is not commented out.

Enabled

M567 P3 E1:1 ; Configure filament assist

Disabled

;M567 P3 E1:1 ; Configure filament assist

Next, add the second drive to the M563 line.

Was

M563 P5 D2 H7 L-1 ; Define tool 5

Should be

M563 P5 D2:3 H7 L-1 ; Define tool 5

Note: this is a typical Tool 5 definition for a 3-FDM configuration (where Drives 0, 1, and 2 are associated with the tools at the turret, and Drive 3 is the assist). If you have a 5-FDM configuration, your assist will be "5" instead of "3".

Save the file and restart the machine.

The current of the filament assist drive is set much lower than the primary drive. The motors easily stall when the filament cannot be pushed further into the guide tube.