This is the 1/2A Starduster X of Don DeLoach in Colorado Springs. CO. Don is a top competitor in all classes of free flight. This shows how he uses the Micro I to give him a quick DT. This method was published in the NFFS Free Flight Digest and is shown in our Helpful Hints area in this web site. According to Don, the spring is 0.009" wire wound on a 2 mm mandrel. The loop is Dacron line and it is placed in a scroll groove below the engine kill wire. Test this to be sure you do not have too much drag on the scroll and cause the timer to slow or stall.

The pressure bladder, fitting, check valve, and fuel line are from Texas Timers, as is the radial mount for the TD engine.