How to Make a Glass Bottle Cutter - DIY Wine Bottle Cutting Tool!
By the way, that flashlight allowed the 18650 battery to slide 12 mm inside the screw base. I bought it at Costco in 2 pack, in 2005. It was just right for this conversion.
Very good idea. I have used this method with success. Please note that Li Ion replacement battery is 18650 and charge limit is 4.2 volts. I use 14500 (AA) size in miniature flashlights that use 1.5 volt or 1.2 volt rechargeable batteries. I find that these batteries charge to 4.2 volt limit in a cheap dual AA chargers. Example Use a blank short circuit instead of one battery in series. The older Li PO4 type 14500 batteries are charged to 3.2 volts. Be careful not to overcharge the batteries. May overheat, leak, explode or become non rechargeable.
3D Printing Class