Petromax LM500 Anti Shock Insert

Heyhooo


This is a shock absorber I designed for the Petromax LM500.

https://www.youtube.com/shorts/hlhutxKBYMc

The Problem
Quite soft impacts from the direction of the battery axes are enough to temporarily disconnect the power supply. That is due to too soft springs & or too much space calculated for the batteries.

This has happened to me frequently, of course, when I've lightly bumped the lamp against something or haven't placed it very carefully on a table.

The Solution
I designed this space holder/ tensioner to fit beneath the batteries and the body of the lamp. It does not interfere with the springs at all but adds some tension (dependant on the softness of the TPU you use) on the batteries itself. So they won't disconnect any longer. Even if you bump against sth. quite hard.

Material
Since the design is based upon a implemented tension you have to use flexible materials like TPU.

I did use TPU with A98 Shore hardness. So every normal and easy to print TPU should work fine for the job! (No extra soft TPU necessary)

Assembly
I like to assemble the bottom 2 batteries first and then add the Insert behind them. Make sure it fits properly and presses evenly against the batteries.

After that I add the top two batteries.

To remoove the Insert I just use a screw driver or sth. similar and insert that into the hole to pull it out easily.

Disclaimer

Hard materials like PLA/ PETG etc will probably not work and might damage the batteries or lamp!

After inserting or removing the batteries, check all parts, such as the batteries and contacts, for damage!

Please do not use damaged batteries.

Have fun!