21700 battery storage tray for 8 cells with polarity marks
A desktop tray that keeps eight 21700 lithium cells upright and separated, handy for vape, torch, power bank and e-bike battery projects. Each cell is 21.4 mm in diameter and 70.6 mm long, so the tray has eight 22 mm bores 35 mm deep on a 26 mm pitch in two rows, a 1.5 mm finger notch at the front of each bore and raised plus and minus symbols embossed 0.6 mm on the rim so you can track which cells are charged. The base is 4 mm thick with 1.6 mm walls between cells, and a 3 mm chamfer at the bore mouth guides the cell in. Prints flat in one piece with no supports.
A tray sized to the exact cell keeps wraps from being scuffed, which loosely fitting downloads cause. In SpeakCAD you describe your cells, preview the tray free in the browser, switch to 18650 or 26650 or add a lid in the chat, and download the STL.
Design a battery storage tray for eight 21700 cells with 22 mm bores 35 mm deep on a 26 mm pitch in two rows of four, a 4 mm base, 1.6 mm walls between bores, a 1.5 mm finger notch per bore, a 3 mm entry chamfer and 0.6 mm embossed plus and minus marks on the rim.