This DIY star tracker is built around a SkyWatcher Star Adventurer declination bracket, a 28BYJ‑48 stepper motor with ULN2003 driver, and a simple hardware control interface using a potentiometer and a toggle switch to control N-S direction.
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The actual Dec bracket is not intended for constant tracking purpose, rather to hold the payload on to the SkyAdventure’s tracker , However with its sturdy build it was put to a test with a Celestron 130 EQ’s OTA and it was able to track without major mechanical stress.
Please use this cautiously as its just a proof of concept & it is not an actual product !!!
Concept and Purpose
The main idea is to reuse the declination bracket from a Star Adventurer as a precise mechanical platform and add a low‑cost motorized drive on the declination axis for wide‑field astrophotography.
Instead of a classic barn‑door tracker, the build leverages the bracket’s worm/gear and clutch for smooth motion, while the stepper handles slow, controlled tracking or fast slews depending on potentiometer setting.
Cost
The DIY tracker comes in at a tiny fraction of the cost of professional portable star trackers while still giving usable tracking for light camera rigs (upto 4kg of payload)
- Commercial portable trackers from major brands generally sit in the mid‑to‑high five‑figure range 35k - 70k.
I managed to keep the cost down under 8K including all required parts. Refer the BOM for detailed list.
Mechanical Build
- The stock Star Adventurer declination bracket is used as the moving axis, so you still get the fine DEC adjustment knob and the ability to lock/unlock the clutch.
- The base of the declination mechanism is bolted to a 100 mm aluminium extrusion using a standard cheese plate, which gives a rigid, modular spine and plenty of 1/4"-20 / 3/8" mounting options.
- The mount can be attached to any tripod using the HOT-L-Type Quick Release Camera Vertical Plate.
- The extrusion/cheese‑plate assembly is drilled so it can be dropped onto almost any photo/video tripod via a central mounting screw, effectively turning any sturdy tripod into a tracking platform.
- The bracket is driven by a classic GT2 20 - 36 Teeth pulley with belt to eliminate any mechanical tension / vibrations.
Drive Electronics
- Motion is powered by a 28BYJ‑48 5 V stepper motor paired with its ULN2003 driver board, a very common and inexpensive combo used in many DIY projects and the whole setup is powered by Arduino Nano to keep the circuit / encolure portable. Code is in the GitHub
- Power comes from a simple 5 V source (USB bank or 5 V regulator), making the whole tracker easy to run in the field with typical astro‑imaging power setups.
Control Interface
- A panel‑mounted potentiometer (wired to the controller) sets the motor speed, allowing anything from very slow tracking (wide field long exposures) up to relatively fast slewing for framing Celestial objects like Moon/Sun Or even Comets.
- A flip SPDT switch on the control box reverses motor direction, so you can quickly change between CW and CCW depending on hemisphere or how you have the rig oriented.
- This simple hardware interface means the tracker can be run and tuned in the dark without needing a laptop, keypad, or display, which is ideal for field use.
Mounting and Use
- On top of the declination bracket you can mount a ball head or lens collar to hold a DSLR or mirrorless camera and lens, using the same dec bracket ergonomics as the original Star Adventurer setup.
- Since the whole assembly sits on a 100 mm aluminium extrusion that bolts onto any tripod, it is easy to swap between tripods or integrate into a larger imaging rig.
- Combined with reasonable polar alignment, this DIY star tracker should handle wide‑field exposures with a lightweight camera/lens while keeping the build compact, modular, and relatively inexpensive.
Output
Here is the stacked picture of Orion Nebula shot on a Bortle 5.5 scale sky during Dec star party.
The Payload had a Canon 7D with a Samyang 135 F2 Lens, together the payload was around 3.5 kg
Materials used:
- SkyWatcher S20560 Star Adventurer Dec Bracket ~ 5K imported
- 360 Degree Rotating Panoramic Ball Head with 1/4 inch Quick Release Plate ~ 1.5k on any e-commerce sites
- 1/4 Inch to 3/8 Inch reducer Bushing Set to mount the ball head to the Dec Bracket ~100 Rs
- 28YBJ-48 DC 5V + ULN2003 Driver Board + Arduino Nano + 10K Pot + 20-36 Pulley wheel and GT2 200mm belt ~550 Rs
- 2040 100mm aluminum extrusion profile ~100 Rs
- 8Pcs M5 10mm Hex screws & 10 Pcs TNut M5 ~ 50 Rs
- Aluminum V slot Gantry Plate for 2020 profile for 3d Printer (Cheese plate) ~ 400 Rs
- A Bracket to mount the stepper motor.