FAQ
TL;DR: For a 2-inch conductive, springy contact on a rotating potato-gun igniter, use 6061‑T6 aluminum or spring steel; “sliding contacts are self-cleaning.” [Elektroda, DAVID CUTHBERT, post #21661023]
Why it matters: This FAQ helps hobbyists choose and mount reliable sliding contacts for taser-based multi-barrel ignition.
Quick Facts
- Target strip size: 0.5–0.75 in wide, ~2 in long for each barrel pass. [Elektroda, Andrew LeVino, post #21661005]
- 6061‑T6 aluminum works; oxide breakdown occurs at taser voltage; sliding contact self-cleans. [Elektroda, DAVID CUTHBERT, post #21661023]
- Spring steel is hard, inexpensive, and easy to source; ultra-low resistance isn’t critical for a taser. [Elektroda, Bob Loy, post #21661011]
- Beryllium copper is springy; its “non-sparking” claim concerns mechanical sparks, not electric arcs. [Elektroda, Bob Loy, post #21661008]
- Off‑the‑shelf clips/plates: Digi‑Key battery contacts and Seastrom spring clips; sample BeCu available. [Elektroda, Todd Hayden, post #21661022]
What metal works best for a conductive, springy strip on a rotating taser ignition?
Use 6061‑T6 aluminum for an easy, robust sliding contact, or spring steel for durability against repeated rakes. Aluminum’s oxide gets punched through at taser voltages, and sliding action self‑cleans. Spring steel is cheap and widely available. [Elektroda, DAVID CUTHBERT, post #21661023]
Is beryllium copper (BeCu) a good choice here?
Yes, for springiness and stable contact pressure. Its “non‑sparking” property refers to preventing mechanical sparks, not stopping electrical conduction. It will still pass taser discharge to your barrel contacts. Consider clip forms if you need defined preload. [Elektroda, Bob Loy, post #21661008]
What size should the contact strip be for each barrel pass?
Build around a 0.5–0.75 inch width and about 2 inches length so the barrel plate reliably sweeps the contact during rotation. This footprint balances contact area and manageable spring force in compact builds. [Elektroda, Andrew LeVino, post #21661005]
Where can I buy suitable spring contacts or clips?
Repurpose battery contacts or spring plates from suppliers like Digi‑Key, or order spring clips from Seastrom. Some BeCu manufacturers will provide samples. These parts give consistent pressure and easy mounting. [Elektroda, Todd Hayden, post #21661022]
Will a simple steel spring work as the brush?
Yes, a metal coil or leaf spring can flex and return to position during each sweep. Watch for a failure edge case: localized arcing can cause micro‑welding of the spring to the track under poor alignment or excessive pressure. [Elektroda, Steve Lawson, post #21661012]
How do I keep visible sparks to a minimum for a safer user impression?
Favor a solid sliding contact over intentional air gaps. Avoid pointed electrodes facing the track, and use smooth, flat interfaces. As one user noted, visible arcing can be unsettling to operators. A continuous brush‑on‑plate contact reduces arc length. [Elektroda, Andrew LeVino, post #21661017]
Could I adapt a motor commutator approach for multi‑barrel firing?
Yes. A commutator provides timed conduction via segmented copper and stationary brushes. One proposal ties opposing segments to a barrel, with an event every 180 degrees. This gives robust, repeatable timing on a rotating assembly. [Elektroda, Frank Bushnell, post #21661020]
Quick how‑to: build a simple commutator contact for a rotating ignition ring?
- Salvage a suitable DC motor; keep the commutator and shaft.
- Remove windings; connect each barrel to opposing commutator segments.
- Mount fixed brushes to feed the taser output as the shaft rotates. [Elektroda, Frank Bushnell, post #21661020]
What is a commutator, in plain terms?
A commutator is a segmented conductor on a rotating shaft. Stationary brushes touch the segments to route current at specific angles. In this project, segments can map to barrels, giving synchronized firing as the cylinder turns. [Elektroda, Frank Bushnell, post #21661020]
Can I use a PCB track and a spring-loaded ball for smoother contact?
Yes. A ball catch with adjustable spring force can ride over a copper PCB track. This offers low-friction, self-centering contact and easy force tuning by swapping springs or adjusting preload. [Elektroda, Sarah Harris, post #21661021]
Does aluminum’s oxide layer block the taser current?
Not in this setup. At taser voltage, the thin oxide breaks down. Sliding contact also wipes and refreshes the interface. As the contributor put it, “sliding contacts are self-cleaning,” which helps maintain reliable ignition. [Elektroda, DAVID CUTHBERT, post #21661023]
Is deliberately arcing across a small air gap a workable strategy?
It can work, since a spark uses ionized air as the path. Keep the gap tiny to limit energy loss before the chamber spark. A pointed rod near the strip starts the arc at a lower voltage. [Elektroda, Steve Lawson, post #21661015]
What tip materials survive repeated tiny arcs if I try the gap method?
Use hard, high‑melting materials like tungsten carbide or titanium drill bits for the pointed electrode. Expect erosion; design for adjustability or replaceable tips to maintain a consistent gap over time. [Elektroda, Steve Lawson, post #21661016]
Any sourcing tips beyond electronics suppliers?
General hardware outlets carry springs and small metal stock. Ask auto parts stores for specific spring dimensions if needed. Older electronics retailers carried hobby materials, but specialty distributors now offer better part selection online. [Elektroda, Steve Lawson, post #21661012]
What is beryllium copper (BeCu)?
BeCu is a copper alloy with beryllium that combines decent conductivity with strong spring properties. It resists fatigue and keeps contact force over many cycles, making it ideal for clips and brush fingers. [Elektroda, Bob Loy, post #21661006]
What’s a practical takeaway for first‑time builders?
Keep it simple: a 0.5–0.75 inch by ~2 inch 6061‑T6 aluminum or spring‑steel brush against steel plates. Scale later if needed. This balances availability, durability, and reliable conduction for hobby builds. [Elektroda, Andrew LeVino, post #21661005]
