3D-printable covers for the AbleNet Jelly Bean accessibility switch. Each cover adds a distinct raised tactile texture to the top of the switch, so a user who relies on touch (or who has low/no vision) can tell two Jelly Bean switches apart without looking — a physical "Tangible Symbol" bonded to that switch's function.
Printed covers in PLA, fitted to Jelly Bean switches alongside an uncovered switch.
Jelly Bean switches are often deployed in sets — e.g. wired to different sounds, messages, or steps in an activity. Out of the box, every switch looks and feels identical, so a non-visual user has no way to know which switch does what. Snapping one of these textured covers onto each switch gives every switch a unique, consistent tactile identity that can be paired with its function (for example: ribs = "next," cross = "stop," dots = "music").
All covers share the same footprint and are sized to fit over the Jelly Bean's actuator cap:
| Dimension | Value | Approx. |
|---|---|---|
| Inner (fit) diameter | 63.4 mm | 2.50 in |
| Undercut | None — straight pull, no retention lip | |
| Outer diameter | 68.4 mm | 2.69 in |
| Overall height | ~16 mm (varies slightly by texture relief) | 0.63 in |
Millimetres are the authoritative values. The inch column is for getting a feel for the size only — don't design to it. The fit diameter in particular is a calibrated value with a narrow window: 63.4 mm was snug against a real switch while 63.8 mm and above were all too loose, and that whole 0.4 mm window is under 0.02 in. Rounding the fit diameter to 2½ in will not give you a working part.
That testing was done on a Bambu Lab A1 mini, 0.4 mm nozzle, PLA. The value is calibrated, not theoretical — if you print on a different printer, nozzle, or material, re-check the fit before trusting it.
| File | Pattern | Notes |
|---|---|---|
01_parallel_ribs_id63.4mm.stl |
Parallel ribs | Direction-dependent: feels different along the ribs vs. across them |
02_concentric_rings_id63.4mm.stl |
Concentric rings | |
03_coarse_grid_id63.4mm.stl |
Coarse grid | Two-directional line pattern, kept coarse to stay distinct from layer-line noise |
04_large_cross_id63.4mm.stl |
Large cross | Meaning-bearing symbol rather than a texture |
05_dot_pattern_id63.4mm.stl |
Dot pattern | Low direction-dependence baseline pattern |
06_left_chevron_id63.4mm.stl |
Left-pointing chevron | Encodes direction; line width ≈5.2 mm, relief ≈1.4 mm |
Files are binary STL. Pick as many patterns as you need distinct switches — each one is a self-contained, ready-to-slice model.
None of these STLs include modeled/embedded print supports — each file is only the finished shape meant to be touched. Supporting the internal ceiling is left to the slicer:
- Orient the part opening down, tactile face up.
- Auto-generate Tree / Organic supports (this was found to work far better than no supports or a small number of hand-modeled support posts).
- Check the layer preview to confirm the internal ceiling is actually supported before printing.
- After printing, remove the tree supports through the opening with needle-nose pliers, and check for leftover burrs or support fragments — especially on the tactile face — before fitting the cover to a switch.
Modeled supports were tried and abandoned: printing with no supports let the internal ceiling sag, and three hand-modeled breakaway pillars removed cleanly but did not provide enough support density. Slicer-generated tree supports printed reliably and peel out easily, so the STLs carry only the finished shape.
The patterns are deliberately coarse. FDM layer lines are clearly perceptible to a fingertip, so a tactile feature has to be large enough to read over that background texture — subtle patterns would be lost in it.
- Slice and print the covers you need, one pattern per switch.
- Fit each cover over the top of a Jelly Bean switch's actuator cap (63.4 mm recess).
- Assign each pattern a consistent meaning across your switches so it can be learned and recognized by touch.
Before putting a cover into real use, check that it does not interfere with how the switch works: it should not increase the force needed to activate the switch, and it should not come loose in use.
Copyright © 2026 Toshimitsu Yamaguchi
Licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). You are free to share and adapt this work, including commercially, provided you give appropriate credit. See LICENSE for the full terms.
Suggested attribution:
Jelly Bean Switch Tangible Symbol Covers by Toshimitsu Yamaguchi, licensed under CC BY 4.0. https://github.com/YamaguchiToshi/JellyBeanSWcover
If you adapt these covers — new patterns, a re-calibrated fit diameter, a different printer profile — sharing what you learned is welcome but not required.
This work is provided without warranty of any kind, as set out in the license.
Jelly Bean® is a trademark of AbleNet, Inc. This is an independent, unofficial accessory. It is not affiliated with, endorsed by, or supported by AbleNet, and using it may affect any warranty on your switch.