A Better Remote Launcher For Control Line Models
When I wanted to practice the F2B schedule at short notice and there was no one else available to help, I had to improvise some sort of release mechanism. Simple enough and numerous ways of doing it.
I soon found they all had one drawback. The model has to be anchored to the device or mechanism before starting the engine; unless a lot of dangerous contortions involving a running engine and spinning prop are your sort of thing. Not so bad on a small model, but anything around a .29 and above are not to be trifled with. I still bear the permanent scars received many years ago from a PAW, and that was 2.5 cc
What was needed was something that would allow me to start the engine in any position, upright or inverted, then simply push the model backwards into an automatic secure lock.
The original mechanism. (Circa 1980's)
The usual way of anchoring these things to the ground is a couple of screwdrivers. Sufficient if you are on grass or something equally soft. Problem was, I was doing 90% of my flying of runways or concrete. Simple solution, use my toolbox, which was always with me when I went flying.
How it was used in real life.
So there we have it, and if I may say so myself, an elegant solution to my problem. I hope the idea will help someone else if they find themselves in the same predicament.
A drawing with dimensions is available
The functioning of the device relies on the model having a tail wheel wider than the slot to hold the model in place.If a simple skid is used a small bar soldered horizontally, or part of the skid bent sideways should achieve the ends.
The shape of the catch is also very important, the bit that does the work forms an arc, with it's radius centered on the pivot screw. If the inner angle is 90 degrees it is NOT safe!
The spring tension should be light enough to allow the model to be pushed in easily, and strong enough to make sure it latches back once the tail wheel is in place. This is in fact, quite floppy.
When working correctly no amount of pulling or shaking the model should cause the catch to release. Please test this first before a live launch, for your own safety, as well as everyone elses....!