Our flight simulator for MagButterfly projects

A list of main components, scripts, 3d printing/laser cutting files, instructions

A flight simulator is a specialised experimental setup designed for studying the orientation and navigation of flying insects. It serves as an analogue to Emlen funnels, which are widely used in avian research to investigate the orientation behaviour of migratory birds. It was invented by Henrik Mouritsen and Barrie Frost in the early 21st century [Mouritsen, Frost, 2022], leading to a significant increase in research on monarch orientation and navigation over the following two decades. Now, flight simulators in various modifications are used not only in studies on monarch butterflies but also on other insects, including European butterflies [Nesbit et al., 2009; Pakhomov et al., 2023, 2025], hoverflies [Massy et al. 2022], and moths [Dreyer et al, 2018; 2025 Hui et al, 2023].

Guides:

The flight simulator is constructed from non-magnetic materials (PVC, aluminium, PETG) and consisted of three main components:

Flight Chamber – A white plastic cylinder (45 cm in diameter, 50 cm in height) is placed vertically on a plastic/aluminium table. At the centre of the table, a 120-mm diameter 3D-printed plastic pipe (5), perforated with hundreds of 3-mm holes, create a laminar airflow (≤ 1 m/s). This airflow, generated by a PWM-controlled computer fan, is designed to stimulate tethered butterflies into active flight (Mouritsen & Frost, 2002). Most components are designed using Autodesk Fusion 360 for for fabrication via laser-cutting and 3D printing.

Butterfly Attachment System – A non-magnetic rod is mounted on top of the cylinder, with an encoder at its centre. A fine tungsten rod (15 cm long, 0.5 mm in diameter) serve as the encoder shaft, connecting to the encoder (1). To facilitate quick and secure attachment, a small plastic tube (20 mm in length, 2 mm in diameter, with a 0.5 mm hole) is affixed to the distal end of the rod. All procedures are non-invasive and do not harm the butterflies or moths; after testing, they are released in good body and wing condition and can continue their migration.

Video Recording System – The system records insect flight for behavioural and orientation analysis using using DeepLabCut or custom-written scripts. In the classical version, an optical encoder (1) is used for this purpose.

Two miniature video cameras (2; Waveshare Electronics, model H) are symmetrically positioned around the tungsten rod, with one capturing the butterflies’ behaviour from above. Using two cameras instead of one ensure a symmetrical environment within the flight simulator. A Raspberry Pi 4 single-board computer (3) connected to a laptop (6) is used for real-time monitoring of insect flight behaviour and to store raw video footage from each test for further analysis.

Various types of information about the migratory flight of an insect in a flight simulator can be extracted from video files, including , activity patterns (flight/non-flight), and.

flight tracks

activity patterns

flight direction

custom-written neural network

in DeepLabCut

Part of simulatorComponentQuantityPrice (GBP)LinkComments
Videorecording systemVideo camera 228RobotShop (UK)
224PiHutalternative
Main computer (raspberry pi)143PiHutRaspberry Pi 3 or 4
Camera cable 15PiHutFor Rasp Pi 3 and 4, Rasp Pi 5 – 50 cm cable only
Encoder systemE4T encoder120US Digital
Encoder cable (3 m)122US Digital
DAQ device1475US Digital
Flying chamberClear acrylic tube (450 mm OD)1690PlastockPrice for 2.1 m tube = 4 cylinders
Custom-made cylinder1~ 180Different supplierswhite plastic sheets, wooden rods, and two laser-cut clear acrylic circles
Plastic tabletop with a central hole for a fan150Local laser-cut companycreated in Autodesk Fusion 360
Air fan tube1custom-made and 3D printedcreated in Autodesk Fusion 360
Computer PWM fan 128AmazonSilent fan powered via USB from power bank + fan speed controller
Network5V Splitter18AmazonIf you need to connect several Raspberry PIs to one laptop (power bank powered, no need electricity)
Part of simulatorComponentQuantityPrice (GBP)LinkComments