3D Printed Flashlight - Fast print, snaps together, no tools required!

Introduction

This model is a redesign of my keychain flashlight assembly, based on feedback and assembly observations. The assembly process required tools, sometimes insulating tape, and a non-intuitive assembly process.

Recommended print settings:

• Material:  PLA

• Layer Height: 0.20

• Infill % : 15+

• Supports: No

• Print Orientation: Default as modeled

Assembly

You will need the following items:

1. One complete print of this model.

2. CR2032 battery

3. 5mm LED - standard Dual in-line package (DIP) with anode and cathode leads, white color is recommended, as it's compatible with the CR2032 3V supply.

4. Optional - Keychain

Assembly steps:

1. Start with the side with the raised snap features - place it as shown, with the battery holder facing up.

   

2. Slide the LED in completely - the longer lead (anode) is recommended to be on the bottom, but it will work the other way as long as the battery polarity aligns.

   

3. Check that the LED is completely inserted - in this example, the flat top LED is almost flush with the edge, round head LEDs may stick out a bit more, but the bump on the base of the LED should be entirely within the housing slot.

   

4. Insert the battery between the LED leads (in this example the positive side is down, to match the LED polarity). If the LED lead is touching the battery and turning on, bend the upper lead slightly away from the battery as shown.

   

5. Press the top of the flashlight straight down onto the assembly.

   

6. At this point, the assembly is complete. The light is turned on by pressing down on the center.

   

   1. Optional - add a keychain or keyring.

      

Troubleshooting:

If the LED fails to illuminate when the center is pressed:

1. Check that the polarity matches: the longer LED lead should touch the positive (+) side of the battery.

2. Check the battery voltage.

3. Try a different LED.

If the lamp is stuck on, follow the steps below (battery replacement) to disassemble, and adjust as necessary.

Battery Replacement:

Insert a flat screwdriver into one of the slots on the side, and twist gently to pry the assembly apart.

Design history/iteration:

1. Replaced screws with snap-fit posts - this worked, but the opposite corners lifted during operation.

2. Added two additional posts - improved retention, but the posts easily snapped off when disassembling.

3. Changed to thicker square posts for increased strength, an improvement, but posts still broke occasionally.

4. Replaced square posts with a bar for increased strength - the bar didn't break, but the front seam of the flashlight lifted up during operation.

5. Replaced square bar with semicircle feature to improve stress distribution and minimize flexing.

6. Recessed the retention features to stay inside the assembly body.