Filament Cutter User Guide & Troubleshooting
Overview
The Infinity Flow Filament Cutter is a compact, mechanical accessory designed to prevent print failures caused by tangled filament, bent ends, or other obstructions in your filament. It helps avoid jams in your Infinity Flow S1’s, AMS’s, and other MMU units— keeping your printer running without interruption. It can even be used right on your 3D Printer to prevent a clogged extruder.
The cutter works by automatically trimming the filament end before reloads. This removes common failure points that can cause failed prints, especially in automated or multi-roll setups.
Automatically Cuts Off:
- Bent Filament Ends
- Tangled filament
- Taped Filament Ends
- Glued Filament Ends
A labeled diagram of the cutter is included below to show key parts.
Installation Instructions
Mount Specific Setup Guides
To see how to install filament cutters on your S1 click here: Filament Cutter S1 Setup Guide
To see all of our setup guides click here: All Setup Guides
Custom Mount Design Guide
Click here to view our custom mount design guide and to Download Free CAD Files.
Best Practices
Mount the cutter just after the filament leaves the roll but before it enters your S1, AMS, or extruder. The cutter should sit inline with the filament path and allow smooth movement through the cutter.
⚠️ The cutter’s inlet tube must make direct contact with any obstruction (like bent filament, tangles, or tape) in order to trigger a cut.
If the tube can’t physically reach and press against the obstruction, the cutter will not engage.
We recommend using a filament guide — a small, teardrop-shaped part that attaches to the cutter’s inlet tube.
This guide keeps the inlet tube properly aligned and prevents miscuts. Without it, the tube can get caught on the spool itself, causing false triggers. This is especially common on rolls with large side cutouts.
Using the Cutter
Once installed, the cutter works automatically. It sits idle during normal filament feeding, and only activates if an obstruction is detected while printing.
Detent Positions
The cutter has two detents that control how much force is needed to trigger a cut:
- Detent 2 (Default) - Requires more force to cut. Less prone to accidental cuts.
- Detent 1 (Sensitive Mode) - Requires less force to cut. Easier to trigger
** If the cutter is cutting too often or without any visible obstruction, switch to Detent 2.
** If the printer can not activate the cutter while in Detent 2, try Detent 1.
Resetting the Cutter
After each cut, the blade mechanism must be reset manually. This is done by pushing the slider up until it clicks into one of two detent positions.
Troubleshooting
Cutter is triggering when there is no obstruction (Miscuts)
Symptom: The cutter is activating when there is no obstruction in the filament path, causing premature cuts and filament runouts mid-print.
- Cause 1: The detent force is too low.
- Solution 1: If using detent one (the sensitive setting), switch to detent two so that the cutter requires more force to trigger (see diagram above).
- Cause 2: There may be excessive friction in the cutter inlet due to a long or sharply bent tube.
- Solution 2: Try shortening the inlet tube or reorienting the cutter so that the filament does not need to make any sharp turns before entering the system.
- Cause 3: Holes in the filament roll are hitting the inlet tube and pushing it into the cutter.
- Solution 3: Make sure to use a filament guide as seen in the diagram above to prevent this. Depending on the severity of this problem with your filament rolls, a custom filament guide may need to be printed.
Filament doesn’t cut all the way through
Symptom: The cutter activates but will not cut all the way through the filament. The filament will get caught in the cutter causing filament grinding or motor skipping in the S1/AMS/3D Printer. This is more common with very hard filaments (especially for filaments with Carbon Fiber or Glass Fiber).
- Cause: The 3D printer (or AMS) does not have enough grip to pull the filament you are using through the cutter.
- Solution: Clean out the gears of the S1, AMS, or 3D Printer and if possible increase the preload force on them in order to increase the grip on the filament, preventing slipping.
Cutter does not activate
Symptom: The filament is tangled or caught on something but the cutter does not activate, leading to the printer/S1/AMS grinding filament or skipping.
- Cause 1: The inlet tube is not able to make contact with the obstruction in order to activate the cutter.
- Solution 1: Ensure that the cutter is positioned such that the inlet tube can make contact with the filament roll throughout the entire cutting motion (see the diagram above).
- Cause 2: The 3D printer/S1/AMS is not strong enough to pull past the detent, activating the cutter.
- Solution 2: If using detent 2, switch to detent 1 (see diagram above). If this does not solve the problem, try to clean out the gears of the S1, AMS, or 3D Printer. If possible,increase the preload force on them in order to increase the grip on the filament, preventing slipping.
Cutter is causing filament grinding/skipping motor
Symptom: The filament will get caught in the cutter once activated causing filament grinding or motor skipping in the S1/AMS/3D Printer.
- Cause: The 3D printer/S1/AMS does not have enough grip to pull the filament you are using through the cutter once it has activated
- Solution: Clean out the gears of the S1, AMS, or 3D Printer and if possible increase the preload force on them in order to increase the grip on the filament, preventing slipping.
Filament won’t feed through the cutter
Symptom: When loading, the filament hits a catching point and will not feed through the cutter. This problem is more common for filament that is heavily bent.
- Cause: The filament is getting caught on the internals of the cutter.
- Solution: Try inserting the filament in a different orientation relative to its natural bend in order to get it to feed through cleanly.
Getting Help
Need assistance with your setup or have a question about the cutter?
💬 For community support, setup ideas, and mount designs, visit our subreddit:
🛠️ For returns, exchanges, order issues or technical support that requires direct help from our team, submit a request here:
