Spark gap for Tesla coil

Two types of spark gap

There are two types of spark gap for Tesla coils, one is static and one has a rotating electrode.

Tesla coil with static spark gap 1891:

The most simple Spark gap distance, static:

Rotary spark gap 1892:

While Tesla used rotary gaps extensively and even used them in several patents (514,168 & 568,180), he did not seem too enthusiastic about them in 1892:

“I may here mention that I have also used dischargers with single or multiple air gaps, in which the discharge surfaces were rotated with great speed. No particular advantage was, however, gained by this method, except in cases where the currents from the condenser were large and the keeping cool of the surfaces was necessary, and in cases when, the discharge not being oscillating of itself, the arc as soon as established was broken by the air current, thus starting the vibration at intervals in rapid succession. I have also used mechanical interrupters in many ways. To avoid the difficulties with frictional contacts, the preferred plan adopted was to establish the arc and rotate through it at great speed a rim of mica provided with many holes and fastened to a steel plate.”

Mechanical configurations - Rotary spark gap:

Simple and special spark gap

Simple spark gap, easy to find, the most effective is the engine spark plug:

If we already have spark plugs, just add this device to create a spark gap for the Tesla coil:

We can buy it, or make it ourselves. Buy cheap with some keywords: 

spark plugs

Spark gap

Adjustable spark gap

Special spark gap:

There will be many sparks passing through the gaps set by the copper pipes. This replaces the rotating spark gap, and increases ignition efficiency.

Diagram of the creative spark gap - in particular:

All distances must be accurate and equal. So a coordinate adjuster is needed:

Use the ruler and clip bar to adjust the distance accurately

Related:

• Free Energy Tesla Coil
• Explanation of Plasma on the Tesla Coil