RESPOOL - Universal Print-Twice Twist-Lock Spool for 1 kg Filament Refill

Print one part twice to create a complete reusable spool for standard 1 kg filament refills.

RESPOOL is a two piece reusable filament spool designed for a wide range of standard 1 kg refill coils.

It supports Bambu style refills as well as compatible third party refills with an approximately Ø82 mm cardboard core.

Both spool halves are identical. Print spool_half.stl twice, flip one half, connect the two parts, and twist clockwise to lock them together.

The assembled spool measures:

• Ø200 mm flange diameter

• 67 mm overall width

• Ø55 mm center bore

• Approximately Ø81.7 mm maximum barrel diameter

• Six viewing windows on each flange

These dimensions allow RESPOOL to work with many common printer spool holders, filament dryers, AMS systems, AMS lite systems, and other automatic filament systems designed for standard 1 kg spools.

Refill Compatibility

RESPOOL is not limited to one filament manufacturer.

It is designed for:

• Standard 1 kg filament refill coils

• Bambu style filament refills

• Compatible third party refill coils

• Refill coils with an approximately Ø82 mm cardboard core

• Refill cores with or without alignment notches

• Refill coils approximately 60 mm wide

Compatibility depends on the actual refill core diameter, refill width, and available clearance inside your printer, filament dryer, or automatic filament system.

Before printing, measure your refill core and confirm that it is approximately Ø82 mm.

Twist Lock Connection

RESPOOL uses a three point bayonet locking system to securely connect the two identical spool halves.

• Three locking tongues connect the halves.

• The halves can be inserted in any of three positions.

• A clockwise twist of approximately 15° locks the spool.

• A detent creates a noticeable tactile click.

• A mechanical hard stop indicates the fully locked position.

• The joint is not held under constant spring tension.

• The locking pockets are located inside the barrel.

• The filament rests against a continuous outer barrel surface.

The locking geometry is designed to prevent the halves from separating during normal printing, handling, and filament feeding.

Lock Confirmation Holes

Two Ø2.1 mm witness holes near the flange rim align only when the spool is fully locked.

Look through the holes to confirm that both halves are correctly assembled.

For an optional secondary lock, insert a short piece of 1.75 mm filament through both holes and trim it completely flush.

When using RESPOOL inside an AMS or another enclosed filament system, make sure the filament pin is completely flush and cannot contact surrounding components.

Refill Core Grip

The barrel includes six shallow grip ribs.

These ribs create an approximate Ø81.7 mm maximum barrel diameter and help prevent the cardboard refill core from rotating independently of the spool.

A nominal Ø82 mm cardboard core should slide over the barrel with light contact.

Slightly tighter cardboard cores may compress gently against the ribs.

No alignment notch is required, allowing RESPOOL to support compatible third party refill coils without notches.

Additional Features

• Print the same part twice

• Secure twist lock assembly

• Tactile locking click

• Mechanical hard stop

• Visual lock confirmation holes

• Optional filament pin secondary lock

• Six filament viewing windows per flange

• Viewing windows align when fully locked

• Ø3.5 mm holes for securing the outer filament tail

• Barrel slot for holding the inner filament end

• Continuous outer barrel surface

• Support free printing

• Compatible with many standard 1 kg refill systems

Material Recommendations

PLA

PLA is suitable for normal spool holder, AMS, and room temperature use.

For use inside a filament dryer:

• Keep the dryer at approximately 45 to 50 °C maximum.

• Place the spool flat whenever possible.

• Do not use PETG, ABS, ASA, or nylon drying temperatures with a PLA spool.

PLA does not melt at normal dryer temperatures, but it can gradually soften or deform when exposed to excessive heat for long periods.

PETG

PETG is the recommended material for regular filament dryer use.

Benefits include:

• Better temperature resistance than PLA

• Good layer adhesion

• Low shrinkage

• Good durability

• Suitable for approximately 60 to 65 °C, depending on the specific PETG material

Always check the heat resistance information provided by your filament manufacturer.

ASA or ABS

ASA and ABS are recommended for higher temperature applications.

• Better heat resistance than PLA and standard PETG

• Enclosed printer recommended

• Shrinkage compensation may be required

• Suitable for warmer dryers and enclosed filament storage systems

Compatibility

RESPOOL is designed to work with many:

• Standard 1 kg filament refill coils

• Bambu style filament refills

• Compatible third party refill coils

• Standard printer spool holders

• Filament dryers

• AMS systems

• AMS lite systems

• Automatic filament systems accepting Ø200 × 67 mm spools

Important Compatibility Information

RESPOOL supports Bambu style refills, but it is not limited to Bambu style refills.

A RESPOOL half only locks with another RESPOOL half.

It does not lock directly to an original Bambu spool half or another manufacturer's spool half.

Always confirm:

• Refill core diameter

• Refill coil width

• Spool holder bore compatibility

• Available filament dryer clearance

• Free rotation inside automatic filament systems

This is an original design based on commonly used refill and spool dimensions. No official manufacturer CAD geometry was copied.

Assembly Instructions

1. Keep the refill coil retaining straps attached.

2. Place the first RESPOOL half flat.

3. Slide the refill coil over the barrel.

4. Place the inner filament end into the barrel slot.

5. Position the second spool half over the first half.

6. Allow the three locking features to drop fully into position.

7. Twist the upper half clockwise approximately 15°.

8. Continue past the tactile click until the hard stop is reached.

9. Confirm that the witness holes are aligned.

10. Optionally insert a short piece of 1.75 mm filament through the witness holes.

11. Trim the optional locking pin completely flush.

12. Secure the outer filament end in one of the rim holes.

13. Cut and remove the refill retaining straps.

Opening the Spool

1. Remove the optional filament locking pin.

2. Hold both spool flanges securely.

3. Twist counterclockwise past the detent.

4. Separate the two halves.

Print Settings

• File: spool_half.stl

• Print quantity: 2

• Orientation: Flange flat on the build plate

• Supports: None

• Layer height: 0.20 mm

• Walls: 4

• Infill: 25%

• Infill pattern: Gyroid or grid

• Top layers: 6

• Bottom layers: 4

• Brim: Optional

• Flow calibration: Recommended

• Elephant foot compensation: Recommended if the lock is too tight

Print the file exactly in the supplied orientation.

Do not scale the parts, as scaling will change the refill core fit and twist lock clearance.

Printer Requirements

• Recommended build area of approximately 205 × 205 mm or larger

• Suitable for most printers with a 220 × 220 mm or larger build plate

• Does not fit the Bambu Lab A1 mini at the original size

• Both halves must be printed at the same scale and with the same settings

Estimated Material Usage

One spool half uses approximately 132 g of solid equivalent material.

Print two copies of the same file to create one complete RESPOOL.

Actual filament usage depends on:

• Material density

• Wall count

• Infill percentage

• Top and bottom layers

• Slicer settings

Included File