Holder for 15 Lasers

I'm helping to create a demonstration of what happens to light inside a lens. Using 15 lasers allows us to test the complete range of the lens while being able to find the focal point(s). Also, I just wanted to play with a bunch of lasers. Each laser has individual up/down adjustment using the two screws. With the model shown in the photos, I have not finished aligning the lasers.
Optics Demonstration Example: aim the laser array at a wall, then place a a curved lens in the path of the lasers. See where on the wall the beams end up. Flip the lens the other way, see the effect. Move the lens closer to and further away from the lasers.
Mounting holes are provided to securely strap your laser array to your attack shark.

I have used the rear part of the laser holder to screw and glue a battery holder for a 18650 lithium ion battery salvaged from an old drill battery. I drilled a small hole that intersects with one of the laser holes to allow for a small slide switch. The lasers can be purchased on Aliexpress or Ebay, the price is about $3 for qty=10. Each laser has a current limiting resistor that allows them to operate on 5V. I have found that running them straight from the battery at 4.2V does not cause them to heat up so fast. Caution: leaving this circuit on for too long will run down the battery below its lower safe voltage, which will damage the battery. Turn on this circuit only for short times to protect the battery and to ensure that the lasers are not allowed to heat up the 3D printed material too much. The model in the photo was printed with PLA, but next time I will print with ABS or PETG for its higher heat tolerance.
The project is available to edit on Tinkercad.