CUE - single spool passive drybox top mount for Bambu Lab A1 & A1mini, Prusa Mk3/4 & Prusa mini

CUE - single spool passive drybox top mount for Bambu Lab A1 & A1mini, Prusa Mk3/4 & Prusa mini


Print Profile(2)


For Bambu Lab A1 & A1 mini
For Bambu Lab A1 & A1 mini
18.9 h
6 plates

For Prusa Mk3/4 and Prusa mini
For Prusa Mk3/4 and Prusa mini
18.7 h
6 plates




Please read the instruction guide below. I try to make the guide as comprehensive as possible and will fine-tune it along the way with user inputs.

I do my best to double-check and test the print profile I create. They are up to date with whatever changes I made to the designs. If you are using profiles made by others, please check if they are updated.


UPDATE 06 Mar 2024

Expanding the CUE ecosystem, I have added a bracket for Prusa Mk3/4 and a tabletop bracket (CUE UP) for A1 mini and Prusa Mini. Please choose the correct print profile for the different printers. In addition, I am working with US and EU vendors to provide CUE and also CUE hardware kit (pre-cut acrylic cover, and all the parts in the Bill of Material) . Users can buy CUE read-to-use or print their own and assemble with the hardware as a project. More information on vendors coming soon.


Living in Singapore, South East Asia, the high humidity makes printing pet-g challenging due to the hygroscopic nature of the material. A spool of pet-g cannot be left in the open for long prints and can result in stringing and print failure. I enjoy printing with Bambu Lab PETG-CF, but it requires a dry box to use on the Bambu Lab A1. So I designed CUE.


CUE is an acronym for Cute, Unique, and Enclosed. It is a single-spool passive dry box CU-case that can be slotted into the CU-bracket (mounted on the A1);

  • The CU-case with the filament spool inside can be removed and stored away when not in use.
  • The spool rolls on PTFE tubes for smooth movement.
  • A reusable silica bead cartridge (Dri-Cell) can be easily replaced without the need to open the CU-case.


Due to design limitations, CUE will fit spools with the following dimensions.

  • OD 200-201mm
  • ID 52-54mm
  • Thickness ≤ 71mm

Spools tested:

  1. Bambu Lab spool
  2. Polymaker cardboard spool
  3. Hatchbox
  4. Prusament spool
  5. Esun plastic spool
  6. FusRock clear plastic spool
  7. Creality spool



As with all my design process, I set a few parameters and requirements when designing CUE:

  • Easy and lean design to print.
  • Easy to use ( as much as possible)
  • Mounting on the top gantry of the A1
  • Sturdy and reliable when fully loaded.
  • Secure mounting using screws.
  • Keeps the air within the case dry using reusable silica desiccant.



Ø6mmxL3mm magnets6pcs
M3xOD5mmxL4mm (or M3xOD5mmxL3mm) Brass Inserts6pcs
M3x10mm BHCS (or M3x8mm BHCS)6pcs
3mm Acrylic Cover1pcs (svg & dxf in zip file)

PTFE tube OD4mmID2.5mm

  • 72mm
  • 130mm


4pcs (use the 72mm rig)


PC4-M10 Pneumatic Coupler1pcs






One set of CUE (plates 1,3,4) uses about 418gm of filament and takes 11h10m

The rigs and accessories (plate 6) use 63gm of filament and takes 1h55m

The project profile is tuned for Bambu Lab A1 using Bambu Lab PLA Basic filaments.



Build Plate 1 & 2

  • You only need to print either plate 1(dual colour) or plate 2 (single colour).
  • The time taken to print single or dual colour is about the same as there are only 3 layer changes.
  • I prepare 2 sets of Dri-Cell to be printed because it's always good to keep a spare set.


Build Plate 3

  • This is the CU-case for the filament spool.
  • Support is needed.
  • Print time is about 7h30m and uses 288gm of filament using my print profile.


Build Plate 4

Consist of the cu-bracket for A1 (or Prusa Mk3/4 if you are the 3mf for Mk3/4)


Build Plate 5

Consists of the stl for CUE UP, a tabletop stand for A1 mini and Prusa mini.

Build Plate 6

Consist of:

  • 2 sets of ptfe tube covers and connectors.
  • 72mm rig to cut the ptfe rollers. You will need 4 pcs per CU-case
  • Cu-case magnet installation rig.



Before installation, remove the support structures on the CU-case. You will also need to get the acrylic cover cut to size: the OD=215.6mm and ID=32mm. I have included the dxf and svg in a zip file under the RAW Model Files section.


  1. Install the Ø6mmxL3mm magnets into the CU-key and CU-bracket. Ensure the polarity is right so that both parts snap together.
  2. Install the M3xOD5mmXL4mm brass inserts into the CU-bracket.
  3. Slot the CU-bracket onto the top aluminium gantry of the A1, roughly at the centre. Do not install the CU-bracket at the edge of the top gantry. This is because it will knock against the x-axis gantry. You need a minimum of 35mm gap.
  4. Use the M3x10mm screws to secure the CU-bracket with the CU-bracket cover.


  1. Install the M3xOD5mmXL4mm brass inserts into the Dri-Cell.
  2. Use the M3x10mm screws to secure the grill cover to the Dri-Cell when in use.
  3. Insert Dri-Cell into CU-case to check fitting. If fitting is an issue, you will need to reprint the grill cover with more elephant-foot compensation (0.18mm)
  4. If the fitting is good, press fit 2 Ø6mmxL3mm magnets into the Dri-cell.
    • Please ensure the polarity of the magnets is in the same direction. (VERY IMPORTANT).
    • The holes are supposed to be tight (Ø6.1mm) , I use a mallet to tap them in.
    • The Dri-Cell holds up to 60 grams of silica desiccant which for me can last around 3 weeks.


  1. Insert the CU-case into the CU-case magnet rig
  2. Place the setup on a solid table to press fit 2 Ø6mmxL3mm magnets into the CU-case.
  3. Please ensure the polarity of the magnets is in the same direction and attracts the Dri-Cell.
    • These magnets are what keep the Dri-Cell firmly attached to the CU-case. (VERY IMPORTANT).
    • The holes are designed at Ø6.2mm, I use a mallet to tap them in.
    • If they happen to be loose-fitting, use super glue.
  4. Install the PC4-M10 pneumatic coupler and insert the 120mm PTFE tube thru the coupler.
  5. Use the ptfe tube rig to cut 4 pcs of 72mm each. These tubes will act as rollers for the spool.
  6. Use a 4mm drill bit to push thru the 4 roller holes on the CU-case to remove the single-layer support (optional)
  7. Inset the ptfe tube into the holes.
  8. Ensure that the ptfe tube is flush to the edge.


Images below show how to install the spool into the CUE and onto the bracket.





It might take a while to get used to loading and unloading filament. I have testing it for a month now (different prototypes and the first release). So far it has been keeping my filament relatively dry. All the best and happy printing.



To date, my designs are free to download and use. There is no Patreon or OnlyFan (hahaha). If you like my designs and wish to contribute to my coffee addiction & help fund the filaments and materials needed for prototyping, a donation of $5-$10 to Ko-fi or will be greatly appreciated.



As with all my designs, Prototyping and testing were conducted to ensure printability and meet my own expectations. However, I understand it may and may not work for you. I would request that you read all instructions and print and install them at your own discretion.







Comment & Rating (9)

Please fill in your opinion

This design is amazing! but the model is pushed up by the heater head during printing, Could you please help me fix that?
The designer has replied
1. the build plate has to be cleaned to provide good adhesion. 2. You must reduce the speed if you use non-high-speed pla or petg. change the max volumetric speed from 21 to15mm3/s for pla and even lower for petg. 3. check if you your bed temperature is stable.
great design! do you have plans to remix this to work on the AMS lite?
The designer has replied
The dry box for AMS lite is another design for the future.
Replying to @thrutheframe :
Glad you're considering it! Looking forward to it!
Replying to @thrutheframe :
Ooooh! Please sir!
I've printed this and cut the acrylic cover, excellent design work, but I am confused as to the "2 sets of ptfe tube covers and connectors." What am I missing please?
No more