Parts Ordering
This page records parts that instructors have actually ordered for Moving Rainbow kits, along with what was paid. Listed prices on marketplace sites rarely match the final charge, so real order totals give a better basis for classroom budgeting than the figures in a search result.
For the complete bill of materials, see the Purchasing Guide and Purchasing Your Own Parts.
Order Log
12 mm Tactile Switches with Caps (Momentary Push Buttons)
Recorded September 2026. Estimated delivery: September 24–30.
The listing sells 12 × 12 × 7.3 mm tactile switches bundled with matching round caps (sold as "knobs"). The order combined three variants of the same product listing:
| Variant | Contents per pack | Price per pack | Packs ordered |
|---|---|---|---|
| Green caps | 20 switches + 20 green caps | $2.21 | 2 |
| Yellow caps | 20 switches + 20 yellow caps | $2.02 | 5 |
| Mixed caps | 12 switches + 12 caps (2 each of six colors) | $1.81 | 3 |
Item prices are as displayed at checkout and may differ from the total by a few cents because of rounding.
| Supplier | AliExpress (US storefront), shipped by AliExpress |
| Packs ordered | 10 |
| Switches received | 176 (40 green-cap, 100 yellow-cap, 36 mixed-cap) |
| Caps received | 176 |
| Shipping | Free |
| Additional charges | $1.65, not itemized at checkout |
| Total paid | $21.65 |
| Effective cost | About $0.12 per switch, cap included |
The base kit uses two buttons, so 176 switches supply 88 kits. A class of 20 needs 40 switches, which is two 20-packs.
Caps. Every pack includes matching caps, so a separate cap purchase is unnecessary. The single-color packs suit a class in which every kit uses the same cap. The mixed pack gives each kit two differently colored buttons, which helps students tell the two mode buttons apart when they explain a project to someone else.
Additional charges. AliExpress added a $1.65 line labeled "Additional Charges" at checkout without describing it. The label does not indicate whether it reflects sales tax, an import fee, or a marketplace charge. Budget from the total shown on the final checkout screen rather than the listed prices, and use the effective per-switch cost above when comparing suppliers.
Verification. As with other marketplace parts, test a few switches for
continuity when pressed before distributing a full class set. Marketplace listings
also turn over frequently, so the link above may not remain valid; the search
keywords B3F-4055 12x12x7.3 tactile switch locate equivalent parts.