Hardware-Free Radiation Shield for Environmental Monitoring

This is a hardware-free, fully 3D-printable radiation shield designed to protect environmental sensors (like the FS400-SHT31) from sun and rain. By shielding the sensor, it allows for more accurate ambient temperature and humidity readings while protecting the electronics from the elements.

This model now offers two distinct versions:

V1 (Original): The classic, robust design for those with newer well-tuned printers, like the Bambu Lab X1 Carbon. Top has integrated rods for seamless assembly.

V2 (Improved & Easier to Print): Redesigned for broader printer compatibility, featuring separate, screw-on rods and optimized fin angles for reliable printing on a wider range of machines. Rod can be printed on its side (orient to the rods flat side). 

Here is YouTube video detailing the assembly process for the V1 model, which can be a helpful visual guide for the V2 assembly as well. The assembly process is very similar for both V1 and V2. The main difference is that V2 requires screwing in the separate rods first, whereas they are integrated into the top of V1.

 https://a.co/d/4XhEAoh

⭐ 2025 Update ⭐

Based on user feedback and to improve printability and versatility, I've made the following significant updates:

Introducing Version 2 (V2) - Enhanced Printability:

Redesigned Top & Screw-On Rods: The top piece has been updated. The three support rods are now separate, have a flat side for easy printing and threaded components (longer threads attach to top). This allows the rods to be printed on their side for maximum strength and accuracy, then screwed securely into the top. This significantly reduces challenges for printers that struggle with overhangs or accuracy on the original V1 top. (See attached image for V2 design).

Improved Threading for Rods: The threads for the V2 rods are designed to be "worked in." You may need to screw them on and off a few times to achieve a fully tight and secure fit. This ensures a durable connection.

Optimized Fin Angles (V2): Both the top and fin angles in V2 have been adjusted to 45 degrees. This dramatically improves print success for machines that have issues with steep overhangs, making V2 much more forgiving to print.

Print Info: Applies to all versions

• Material: PETG, ASA, or ABS (White for best results) for outdoor use
• Layer Height: 0.2 mm 
• Walls: 2
• Infill: 25% gyroid
• Supports: None required
• Filament Usage: ~150 g

Parts to Print:

5 Fin setup (V1 and V2)

• Top or TopV2 (1x)
• Rod - 5 fin (3x_
• Fins (5x)
• Bottom 1x
• Mount 1x 
• Nut 3x

9 Fin setup (V1 and V2)

• Top or TopV2 (1x)
• Rod - 9 fin (3x_
• Fins (9x)
• Bottom 1x
• Mount 1x 
• Nut 3x

You can find a mount for a EMT tube .75in and 1in and a mount to screw onto a 2x4. There is a button that is made specifically for the FS400-SHT 31 Sensor. There is another bottom that with a larger opening for people to make there own sensor holders.  The video shows how to assemble the shield. To mount the sensor into the bottom, We use a M4 screw.  You can 3D print a M4 screw and it will work fine. 

Assembly is simple and requires no extra hardware.

For V1 (Original):

• Print all V1 parts.
• Slide the 5 Fin_V1 pieces onto the rods integrated into the Top_V1.
• Slide the Bottom piece onto the three rods 
• Slide your  Mount on to the rods
• Screw on nut and tighten it gently to clamp all together.
• Install your sensor probe, use a M4 screw to tighten

For V2 (Improved - 5-Fin or 9-Fin):

• Print all V2 parts for your chosen fin count.
• Take the Top_V2 piece and firmly screw in the three Rod_V2 parts (longer threads attach to the top). Remember: you may need to screw them on and off a few times to fully seat and tighten the threads.
• Slide your chosen number of Fin_V2 pieces (5 or 9) down the rods.
• Slide on the Bottom piece onto the three rods 
• Attach your Mount to the bottom plate.
• Screw on nut and tighten it gently to clamp all together.
• Install your sensor probe.

Why do you need a Radiation Shield?

A shield is needed for a temperature and humidity sensor to protect it from direct sunlight, rain, and other environmental factors that could significantly affect its readings, ensuring accurate measurements of the ambient temperature and humidity levels by preventing the sensor from getting too hot or wet; essentially, a shield allows the sensor to accurately measure the air temperature rather than the temperature of its surroundings. 

Key points about using a shield for a temperature and humidity sensor:

Accurate readings:

The primary function of a shield is to maintain consistent conditions around the sensor, preventing drastic temperature fluctuations caused by direct sunlight or precipitation, leading to more precise data collection. 

Sensor longevity:

Protecting the sensor from harsh elements like rain and extreme temperatures can extend its lifespan. 

Radiation protection:

Shields are often designed to block solar radiation, which can significantly impact temperature readings, especially during the day. 

Ventilation design:

Most shields have a ventilated structure to allow air to circulate around the sensor, ensuring it measures the true ambient temperature.