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Enclosures & cases
Storage box for four 18650 cells
A lidded box that carries four 18650 lithium cells with each one in its own bore, so the terminals cannot touch and short in a bag. Each cavity is 18.8 mm in diameter and 66 mm long to fit protected cells with a little slack, with 1.5 mm ribs between bores and a 2 mm outer wall. A finger groove at the top of each bore makes removal easy, and the lid closes with two 0.4 mm snap bumps. Print the base upright so the bores come out round. Open the ready-made model free, resize it on your phone or computer, then download a print-ready STL, 3MF or G-code sliced for your printer, free.Opening the ready-made model and downloading it as STL or 3MF are free, no card; AI changes use credits, from Maker at $7.99 a month.No printer? We print this part and ship it to your door. See its priceUpdated
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Change its numbers in the viewer for free, or ask the AI in the chat: wall thickness, hole size, the thing it clips onto. AI changes use 2 credits per request (1 for a quick edit, 3 for a redesign), paid with a plan from Maker at $7.99 a month.3Print
Download a watertight STL or 3MF free, with your numbers and hand edits, or G-code sliced for your printer at the same price. After an AI change the download is included in every plan (4 credits without one).
Dimensions of the ready-made model (editable)
| Parameter | Value |
|---|---|
| cell bore diameter | 18.8 mm |
| bore depth | 66 mm |
| wall between adjacent bores | 1.5 mm |
| outer wall thickness | 2 mm |
| floor thickness | 3 mm |
| number of cells | 4 |
| finger groove width | 6 mm |
| how deep the groove cuts down from top | 10 mm |
| lid height | 6 mm |
| snap bump size (radius-ish bump) | 0.4 mm |
| fit clearance for lid skirt | 0.3 mm |
Example prompt
Design a lidded storage box for four 18650 cells in a row. Bores 18.8 mm diameter, 66 mm deep, 1.5 mm ribs, 2 mm outer walls, 3 mm floor. Finger groove 6 mm wide per bore. Separate lid 6 mm tall with two 0.4 mm snap bumps.
Fit notes
With SpeakCAD the box holds precisely as many cells as you carry, in whatever arrangement fits your pocket: two by two, a row of four, or a flat sleeve. Preview in the browser, then ask for a hinge, a label recess or 21700 dimensions instead.
Questions people ask about a storage box for four 18650 cells
A lidded box that carries four 18650 lithium cells with each one in its own bore, so the terminals cannot touch and short in a bag. Each cavity is 18.8 mm in diameter and 66 mm long to fit protected cells with a little slack, with 1.5 mm ribs between bores and a 2 mm outer wall. A finger groove at the top of each bore makes removal easy, and the lid closes with two 0.4 mm snap bumps. Print the base upright so the bores come out round.
Click Open it free on this page and create a free account (no card): the ready-made model opens in your browser, on your phone or computer, nothing to install. Change its numbers in the viewer for free and download a watertight STL or 3MF free, or G-code sliced for your printer at the same price. An AI change in the chat uses 2 credits per request (3 for a redesign), and the download after it is included in every plan (4 credits without one). Start with Maker: 50 credits a month for $7.99, cancel anytime.
On this page: open the ready-made model free in a SpeakCAD account (no card), change any dimension in the viewer, then download the STL or 3MF free, or G-code sliced for your printer at the same price.
A shared STL is modelled for someone else's measurements. Here you open the ready-made model free, change it to your measurements in the viewer, then download a file sized for the part you actually own, free as STL or 3MF.
Yes. SpeakCAD slices the part on its servers with OrcaSlicer and your printer's official profile (380+ printers, including Bambu Lab, Prusa, Creality and Elegoo), and you download the G-code (a sliced .gcode.3mf for Bambu Lab printers). G-code sliced for your printer costs the same as the STL: included in every plan, free for a part you shaped by hand, 4 credits without a plan for a part with AI work in it. Pick your printer on the printers page to see its profile.
No. SpeakCAD runs in the browser on your phone or computer: the chat, the 3D engine and the live viewer load in the tab. The only file you download is the finished STL, 3MF or sliced G-code.
Print it your way
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