Manufacturer: Paton Hawksley Education Ltd., 17 Ashmead Business Park, Ashmead Road, Keynsham, BS31 1SX Bristol,

• Slit width: 0.2 mm
• Grating: 600 lines/mm
• Dimensions: 105 × 25 mm (L × D)

• Pi 4 (8 GB)
• 64 GB SSD
• Power supply (3 A – 15 W – Pi 4)
• Adapter Pi-camera cable to HDMI, mounted here
• Gelid Solution ICEBERRY Raspberry cooler – integrated heatsink + fan – very quiet operation – Raspberry Pi 4 Model B – 91 × 62 × 33.5 mm – silver

Cooling: The continuously running 5 V fan is very loud .

Cooling: The 5 V fan runs constantly and is very loud. An emitter circuit with transistor and resistor solves this.

There’s space in the case for a 1 kΩ resistor and a BC548B transistor, allowing for regulated fan control via GPIO pin 14.

Setup: Using `raspi-config`, configure pin 14 to activate based on temperature (e.g., from 75 °C) to control the fan.

☛ The fan is now off most of the time, so everything is very quiet.

Using the camera‑to‑HDMI adapter lets you swap the wide, delicate Raspberry Pi camera cable for a standard HDMI cable.

• PCB adapter Raspberry Pi‑Camera to HDMI
  • 2‑pack HDMI to CSI extension adapter for Raspberry Pi camera module with 5 cm FFC flat cable
• 4× M2 screws
• M2 brass spacers

• Raspberry Pi Camera B Rev 2.0
  • Waveshare Raspberry Pi Camera (B), OV5647 adjustable-focus 5 MP FFC (e.g. Eckstein shop)
• 4× M1.6 and 2× M2 screws

The 12 MP has lower resolution! Don’t confuse pixel count with pixel size

• Remove existing lens and replace with this:
• 6–22 mm 5 MP varifocal lens, manual zoom, high-definition
  • M12 mount thread
  • F1.6
  • 6–22 mm 5 MP M12 mount varifocal lens, manual zoom, high-definition network lens for 5 MP security cameras without filter (e.g. Amazon, eBay)

A spacer set (here M2), felt pads, and screws (we need M1.6, M2, M3) should be part of any maker toolkit.

• ALU 8 mm AlMg4,5Mn EN AW-5083, F 28
• Bottom:
  • 2× 2.5 mm holes → M3 thread to be tapped manually
  • Spacing: 37.0 mm
• Front: 4× 1.8 mm holes → camera holder

Alternatively, the camera holder can be 3D-printed. The bottom holes should be 4 mm for M3 threaded inserts.

• ALU 6 mm AlMg4,5Mn EN AW-5083, F 28
• Length: 208 mm, Width: 50 mm
• 2× 3 mm holes → for the spectroscope holder (spacing 23 mm)
• 2× 3 mm holes → for the camera holder (spacing 37.0 mm)
• 4× 2 mm holes → for the camera‑HDMI adapter

Screws on the underside don’t need countersinking since felt strips on the bottom act as protection and provide the required spacing.

The base plate should ideally be aluminum for stability. If no CNC router is available, you can source 50 mm wide aluminum sheets from various suppliers. The QCAD DXF file can be printed as a template for pre‑drilling holes. The holes can then be drilled manually. Alternatively, the base plate may also be made from wood.

• Cap diameter: 24.8 mm (to prevent the cap from falling out!)

☛ Serves as a dust cover—essential to protect the optics, since none is provided!

• Spectroscope print diameter: 25.2 mm (due to the sticker)
  • M3 hole spacing: 23 mm (important for the base plate)
  • Thread inserts
    • M3 pilot hole: 4 mm (for PLA)
    • M5 pilot hole: 6.3 mm (for PLA)
  • M5 thumb screw

• Optional, but recommended.
• Inner hole: ø 15.3 mm
• 2× M2 – uses the camera’s mounting holes to attach the cover.

• Optional, but recommended.
• 4× M2