Most tools sport rechargeable batteries these days, but there’s no need to toss that old flashlight: just replace the cells with rechargable ones!
[monjnoux] had a 3-cell D-sized MagLite lying around—though you could reproduce this hack with a 2 to 5 cell model—which he emptied of its regular batteries and replaced with some 11000mAh NiMHs from eBay. The original bulb was also tossed in favor of a 140-lumens LED.
After disassembling the flashlight, [monjnoux] set about installing the new parts. He replaced the original bulb with the LED, soldering it into place and securing it with hot glue. He then drilled a hole in the body of the flashlight for a DC socket. The charger he purchased is adaptive, detecting the number of cells and adjusting its voltage accordingly. It had the wrong connector, though, so [monjnoux] simply chopped off the end and soldered on a new one. For a hack that comes in at 40€, it’s definitely a cheaper alternative to the official rechargeable model: which costs 80€. And with a duration of 7 hours (though it’s unclear whether this number reflects continuous use), it likely outlasts the official model, as well.
Maglite’s used(?) to be the king of flashlights, but replacing those pesky D-cell batteries is kind of ridiculous in this day and age. So [Travis] decided to upgrade it to make use of the ever-so-common, 18650 lithium-ion battery.
Not looking to purchase any components [Travis] performed this hack using simple recycled household parts. You could solder tabs on the 18650’s so they better mimic a typical alkaline battery cell, but [Travis] notes that because most solder tarnishes the electrical conductivity isn’t always the greatest. So instead, he used aluminum foil. It doesn’t look professional, but it does the job and keeps all the components unmodified so the lithium cells can be used elsewhere if needed. To center the batteries inside the Maglite he used a few strips of cardboard from a case of beer — again, this is just making use of what was available. That being said however, if you wanted to do a professional job on it, nothing is stopping you! A 3D printed 18650 to D-cell adapter would look quite nice… Finally, in order to make the battery spring contact the smaller surface area of the lithium cells, all you have to do is flip it around backwards and slightly bend the inner spring out. That’s about it.
It’s a pretty simple hack we admit, but definitely super handy. In a past project [Travis] also replaced the halogen bulb with a high power LED, making this flashlight even more powerful — and because the LED driver accepts a broader range of voltages it lasts longer too. If you need more inspiration for retrofitting flashlights with LEDs check out this switch-mode driver board hack.
Unfortunately this hack does reduce the Maglite’s thief-head-bashing-ability with such light batteries.
This innocent looking Maglite houses a piston and barrel, making it into a functional pneumatic BB gun. A Maglite was chosen due to its high durability, and easy access to the internals. A schrader valve sticks out of the battery cap, which allows the gun to be charged using a standard fitting. A brass tube is used as the barrel, and a piston controls firing.
Firing the gun is simple. First, the whole thing is charged up to the desired pressure. Then the ammunition is inserted into the barrel. At this point, the rubber piston is held against the end of the barrel by the pressure in the gun. By pushing the pin of the valve in, the piston is able to move back slightly. This acts as the trigger, and causes air to rush into the barrel, firing the BB.
The results are fairly impressive. Using a chronograph, the speed of the BB was measured at 850 feet per second. Using the Gas Gun Design Tool simulator, it was estimated that the gun could fire at over 1000 feet per second, and maybe even break the sound barrier.