AMS Lite Users

A version for the AMS Lite can be found here: https://makerworld.com/en/models/1011533

Change Log:

• Version 2.0.3: 3/8/25
  • Arm Update
    • Two more versions of the Arm were created that create an additional 0.2mm and 0.4mm gap between the filament and the blade to prevent dragging.
• Version 2.0.2: 2/16/25
  • Slide Update
    • The blade has more clearance when retracted to prevent dragging
  • Arm Update
    • The blade has more clearance when retracted to prevent dragging
  • Lock Update
    • The nub is taller for easier toggling
  • Guide Update
    • Lengthened and rounded sides to help prevent snagging on spool sides
• Version 2.0.1
  • Slide Update
    • Corrected the spring thickness numbering on back of slides
• Version 2.0.0: (Now compatible with Sunlu spools!)
  • General Updates
    • It is narrower, smoother, easier, and looks better!
  • Updated the Lock
    • It is more compact.
  • Updated the Slide
    • It has features to make the short tube easier to install.
  • Updated the Body
    • It is more compact to not interfere with narrower spools (Sunlu) or filament clips.
    • It has a groove to make loading filament easier.
    • It has extended rails to better support the Slide.
    • It has a larger slot instead of a Teflon tube at the bottom.
  • Updated the Arm
    • It has a larger cutout for better filament visibility.
    • It is shorter for narrower spools.
    • It has more mechanical advantage, making cutting easier on the Feeder.
    • It has a fin to prevent spool gaps from catching when re-spooling.

What is this?

This is an AMS Saver unlike any other. Not only does it prevent wear and tear on your AMS filament inlet, but it also prevents snags and obstructions from delaying your print!

How does it work?

NOTE: I am actively updating this model as I receive feedback, so if you have any issues please message me and I will work with you to resolve them. Also, check back often for the next improved version!

This AMS Saver differs from the other options because it has a mechanism that automatically cuts the filament if a tangle or an obstruction (taped end of the spool) is detected. This feature is turned on or off with a slider lock. Cutting the filament when a snag is detected allows the printer to automatically switch to your backup filament by setting up the Auto Switch function. If you are running a long print, this can save you hours of delayed print time! If you don't have the Auto Switch function activated, it gives you a few minutes to take action while the printer continues to use the filament in the tubes. You have a few minutes to address the issue and re-feed the filament manually for an uninterrupted print.

Process WITHOUT Cutter

1. Snag is detected by the printer.
2. Printer immediately pauses and the spool is retracted.
3. Warning is displayed "The AMS Assist motor is overloaded. This could be due to entangled filament or a stuck spool. [0700 8010 083713].
4. Printer remains paused until the issue is fixed manually

Process WITH Cutter and WITH Auto Refill enabled

1. Snag is detected by the Cutter (not the printer).
2. Filament is cut.
3. Printer detects the end of the filament.
4. Printer continues to print uninterrupted until all filament in the tubes is depleted.
5. Printer switches to the refill spool automatically and continues to print.

Process WITH Cutter and WITHOUT Auto Refill enabled

1. Snag is detected by the Cutter (not the printer).
2. Filament is cut.
3. Printer detects the end of the filament.
4. Printer sends a warning message that the end of the filament has been detected and needs attention, but the print is not paused.
5. Printer continues to print until all filament in the tubes is depleted (this takes a few minutes).
6. Printer pauses if the tube is depleted before the issue has been fixed.
7. Printer remains paused until the issue is fixed manually
8. If issue is fixed before the filaments in the tubes is depleted then the printer continues uninterrupted.

Compatibility

AMS Style

This is compatible with all AMS for the X1 and P1 series printers. It is not compatible with the AMS Lite. A version for the AMS Lite can be found here: https://makerworld.com/en/models/1011533

Desiccant holders

It is compatible with desiccant holders placed in front of the AMS. 

Spools

It is compatible with all spools compatible with the AMS, even the Narrowest Respool!

Filament

Some engineering-grade materials such as PA-CF may be too tough/strong/hard for the mechanism to cut. If you have trouble try using a new sharp blade. Let me know if you want a version that can work with these materials, and I may design one if there is enough interest. 

Some filaments (ABS, ASA, ect.) have a density that is lower than PLA, so a full 1kg spool includes more filament length. This extra filament length makes the spool diameter so big that there is no room to close the AMS lid with a full spool and the AMS Saver. Unfortunately, the width of the cutter blade and the required arm thickness don't give me any options for making the AMS Saver any thinner. You can still use the AMS Saver with the lid cracked open, or you can install an AMS Lid Riser.

Materials Needed

Filament - The cutting trigger force is dependent on the filament stiffness. I tested with standard PLA, but if you use a different material the trigger force may be too high or too low. Refer to the “Trigger Tuning” section below. 

Filament Cutter - Spares may have been included in your printer shipment, or you can purchase them at the Bambu Store.

PTFE Tube - At least 2.75 inches (70 mm) of 4 mm OD is required. Spares may have been included in your AMS shipment, or you can purchase it at the Bambu Store.

AMS Tape Saver Multi-Tool (Suggested) - This is a helpful tool that helps hold and cut the Teflon tubing. 

https://makerworld.com/en/models/982416

Mechanism Overview

• Actuate the Cutter mechanism by moving the Slide down into the Body. To adjust the trigger force see the “Trigger Tuning” section below.
• Reset the Cutter mechanism by moving the Slide up out of the Body until it clicks and stops. 
• Lock the Cutter by sliding the lock to the Right until an (X) is visible (note that the mechanism must be in the reset position to lock).
• Unlock the Cutter by sliding the lock to the Left until a circle is visible.

Assembly Instructions

 1. Cut Teflon Tubing

• Cut a Teflon (PTFE) Tube section to 1/4 inch (6 mm) and another section to 2.5 inches (64 mm).
• The AMS Tape Saver Multi-Tool is useful for cutting and handling the tubing

2. Attach Teflon Tubes to Slide and Guide

• Insert the 1/4 inch tube into the hole at the bottom of the Slide.

  

• Insert the 2-1/2 inch tube into the hole at the top of the slide and the other end into the Guide.
• Push the Tube into the Slide and the Guide until it stops.
• Hold the Slide and twist the Guide clockwise (righty tighty) while pushing them together to thread the tube into both parts.

• If the tube begins to buckle/twist, you may want to use the AMS Tape Saver Multi-Tool as a clamp to grip and twist the Teflon tube.
• Observe the Tube in the Slide inspection hole and the Guide end to ensure it is fully assembled.

3. Assemble the Arm into the Slide

Note: The default Slide design on Plate 1 seems to have the best trigger force. The trigger force can be changed by using a different Slide model. Refer to the “Trigger Tuning” section below.

• Remove the “REMOVE” tab from the Slide and flatten the nub/flashing.
• Orient the Arm as shown and slide the shaft into the slot.
• Rotate the Arm 90 degrees toward the Slide.

4. Attach the Cutter

Caution: The cutter is sharp! Handle with care.

• Insert the Cutter into the Slide slot and snap the pins into the Arm holes.

5. Attach the Body

• Line up the pins on the Body with the slots on the Arm.
• Insert the Slide into the Body while inserting the pints into the slots.
• The Slide will snap in place. 

• Note that you can disassemble the mechanism by pushing a piece of filament into the hole on the side of the Body while pushing the Slide out of the Body.

6. Attach the Lock

• Push the Lock into the Body until it snaps into place.

7. Attach the Bracket

• Remove the “REMOVE” tab from the Bracket and flatten the nub/flashing.
• Insert one pin fully into one hole.
• Rotate the Body and bend the Bracket to insert the second pin into the second hole.

8. Attach the AMS Feeder

• Slide the Bracket into place on the Feeder so that the tabs in the back fit under the housing.
• Push down on the middle of the Bracket so that the bottom of the Bracket snaps into place.

Note that you can remove the Bracket by reaching down and pushing the bottom of the Bracket free of the Feeder.

9. Attach the Hat

• The Hat is an optional piece that allows for easier filament loading.
• It is recommended that the hat be attached to the filament in the feeder. This lifts the button up and makes it easier to access.
• Slide the short end of the Hat under the front of the Button and slide the Hat back.
• Push down on the back of the Hat until it snaps into place on the Button.
• When loading filament, push back on the Hat and it disengages the rollers to easily slip the filament into the Feeder.

10. Removal and Disassembly

• To remove and disassemble you essentially perform the assembly instructions in reverse as seen in the video above.

Setup and Features

NOTE: The written instructions below are the most updated. The pictures and videos are for reference only and may not be updated with the latest design improvements.

1. Load the Spool 

• Insert the spool into the AMS
• Narrow spools should be shifted to the right such that the left-hand rim is slotted into the channel shown below.
• The moving side of the mechanism should not rub against the side of the spool as this may cause false triggers.

2. Insert the Filament

Ensure the Cutter lock is engaged so you do not accidentally cut the filament while loading it! The (X) is visible when the Cutter is locked.

• Rotate the Body forward to access the AMS Spool Holder.
• Insert the spool into the AMS Spool Holder.
• Ensure the lock is in the locked (X showing) position. The Body can't rotate past the top of the Bracket if the lock is disengaged. This serves as a reminder to lock the cutter when installing filament.
• Insert the end of the filament into the Guide.
• Push the filament through the Saver and into the Feeder funnel.

• Push the button Hat toward the spool while pushing the filament into Feeder funnel until the AMS pulls the filament.

4. Use during printing

• After the filament loading sequence has been completed, unlock the Cutter by sliding the lock to the Left until the circle is visible.

• Ensure you have the “Auto Refill” option enabled on the printer (if you have a backup spool).
• Note: If you find that the cutter is triggering too soon or too late refer to the Trigger Tuning section below.

5. Remove the filament

• Ensure the lock is in the locked (X showing) position. The Body can't rotate past the top of the Bracket if the lock is disengaged. This serves as a reminder to lock the cutter when installing filament.
• Rotate the roll of filament backward until the filament exits the Guide.
• Be sure to not let the end of the filament go free and get tangled.
• Rotate the Body forward.
• Remove the Spool.

Trigger Tuning

The material you use to print the model may be softer or harder than what I used for development. A softer material will create a weaker spring resulting in a lighter trigger and less force to activate the cutter. The inverse is true for harder material. If you are having issues with the cutter triggering too soon (cutting without a tangle) or too late (AMS feeder can't feed) don't worry. I have you covered.

The Slide part has the plastic spring incorporated into it, and there is a number on the back of the Slide indicating the thickness of the spring. The default Slide is marked with "1.8" indicating a spring thickness of 1.8 mm. A thicker spring will compensate for triggering too soon, and a thinner spring will compensate for triggering too late. Plates 2 through 9 have different Slide spring thicknesses, and they are labeled in Bambu Studio with the spring thickness on that plate (a minimum of 1.4 mm and a maximum of 3.0 mm).

If you have a cutter triggering too soon, look at the back of your Slide part and note the number. Print the plate with the Slide spring one increment thicker. Remove the current Slide and replace it with the thicker version. For example, if you have a "1.8" on the back of your Slide, then you should print the 2.0 mm plate. Test this new spring thickness and see if you are still encountering triggering that is too soon. If it is still triggering too soon, then keep increasing the spring width until you find a Slide spring that triggers at the appropriate time. Let me know if you are still having issues and I will help.

Blade Gap Tuning

The blades from Bambu have a large variation in length. This can cause dragging/scraping of the blade against the filament even if the blade is fully retracted. Multiple arm versions were created to compensate for this variation. Follow the procedure below:

1. Print the standard Arm model on Plate 1. If no dragging occurs, then continue using this version.
2. If the blade drags against the filament when retracted, then print the +0.2mm Arm on Plate 10. If no dragging occurs, then continue using this version. 
3. If the blade continues to drag against the filament when retracted, then print the +0.4mm Arm on Plate 11. If no dragging occurs, then continue using this version. 
4. If the blade continues to drag then please message me and I will see how I can help.

Please check out the other models on my profile too!