October 15, 2025
Description
2025-10-20: I added print in place chains! no more filament inserting and no tolerance test needed. BUT you still need to snap the hinge from every chain link free, so it can rotate.
2025-11-16: I added closed chains just like in the real airport baggage conveyor.
This is my interpretation of a modular conveyor belt system. It is a mini modular plug-and-play closed-loop conveyor belt system with a track width of 37mm.
This system includes tracks and attachments, allowing allowing flexible layouts for baggage handling, security checks and passenger flow, and also fitting industrial transport uses. .
Tracks:
Attachments:
If you have an attachment idea to design, you can use the attachment_idea_pins.step in the files (in this stl there are two pins with the exact dimensions a distance for a boolean operation on your 3D model).
All parts connect tool-free using connectors, which makes it possible to build any structure. The conveyor belt is powered by hand, with the option of using LEGOs motors.
Boost MeI dont usually ask for boosts, but I really put a lot of effort into this model. The positive feedback helps me to keep making these models. So if you feel like supporting me, just hit the boost button. Thank you so much :)
My goal was to design a modular mini conveyor belt system.
I started with straight segments, each defined by a specific number of chain links. The 100% straight section contains n chain links (in my case, 12). The 50% straight has half as many, the 25% straight a quarter, and so on — down to 12.5%.
I wanted the 180° curve to use the same number of chain links as the 100% straight (so both have 12 links). The 90° curve should then naturally use half that amount.
An important design goal was that the outer diameter of the 180° curve should match the length of the 100% straight section. That way, when connecting multiple parts, there would be no offset between the start and end of the belt.
At the same time, the inner diameter of the curve should equal 25% of the 100% straight.
Unfortunately, this wasn’t perfectly achievable — the outer and inner diameters ended up about 1 mm larger than planned. This small deviation comes from the discrete number of chain links and their fixed pivot spacing.
The final result:
Despite the small tolerance, the system works very well and looks balanced when assembled.
Please read the description before printing the model to minimize problems.
Let’s say I want to build a closed loop with two straight sections and two 180° turns.
Decide whether you want a conveyor with a drive unit or without one.
The drive unit lets you move the belt manually (with your finger) or by using LEGOs L/M motor or a TT motor.
⚠️ Note:
The drive unit uses a 25% straight segment, so you’ll need to plan its position in your layout.
For example, if you include the drive unit, you might have to shorten another straight to make everything fit correctly.
Before printing, make sure your filament is properly calibrated and dry.
Here’s a helpful video on how to calibrate your filament:
Determine how many tracks and what types you need.
Example layout (with drive unit):
You can print using the Bambu Handy App or Bambu Studio.
=> Repeat the same process for straights, curves, and slopes.
Straights:
Curves:
Slopes:
How many chain links do you need?
| Track Type | Links per Segment |
|---|---|
| Straight 100% | 12 |
| Straight 50% | 6 |
| Straight 25% | 3 |
| Straight 12.5% | 1.5 |
| Curve 180° | 12 |
| Curve 90° | 6 |
| Slope | 3 |
Example:
If you have 2× Straight 100%, that’s 2 × 12 = 24 chain links.
After summing all your track types, you’ll know the total number of links to print (e.g. 84 links).
(Recommended for most users)
Clean your build plate before printing! A bit of glue or adhesive can help with bed adhesion.
Repeat until you’ve printed enough chain links.
Assembly:
Remove the printed chain from the plate and loosen the hinge by twisting it to the side — it should move freely right after.
(Recommended for most users)
Clean your build plate before printing! A bit of glue or adhesive can help with bed adhesion.
Repeat until you’ve printed enough chain links.
Assembly:
Remove the printed chain from the plate and loosen the hinge by twisting it to the side — it should move freely right after.
(More work, but useful if print-in-place doesn’t work well)
First, print the chain tolerance test and follow its instructions — this step is crucial so the links don’t fall apart when inserting the filament.
After printing:
Insert the long filament through the chain links, then cut it cleanly with a cutter knife.
⚠️ Safety Tip: Place a sturdy base underneath while cutting.
Drive unit (for LEGOs L/M motor)
Drive unit (for yellow TT motor)
Airport wall
Baggage separator
Barrier
Decide which ones you want to include in your build.
Bambu Handy App:
Go to “Attachment” → choose the desired attachment plate → select filament and print.
⚠️ Note:
The baggage separator has two separate plates that both need to be printed (due to color changes).
Drive unit (LEGOs L/M motor): Attach motor with compatible axle adapter.
Drive unit (TT motor): Mount motor base and secure the coupling.
Airport wall: Connect directly to the track edge.
Baggage separator: Assemble both color parts together.
Barrier: Four designs available — choose your favorite!
Track Assembly
Connect all straights, curves, and slopes according to your layout.
Insert the Chain
Feed the chain through the full track loop.
⚠️ The chain moves in one direction only — moving it the other way will cause it to jam.
Attach the Drive Unit
Mount the drive unit to the straight section as shown in the reference drawings.
The baggage pieces come from these models (scaled down):
If you encounter any issues or have ideas for improvement, feel free to leave a comment.
I’m always happy to hear feedback and see your own creative builds! 😄
License:
MakerWorld Exclusive License
7,756
JohannesDorig
