As we all know, the problems of a practical radio controlled helicopter (not THE first RC helicopter) were finally overcome by Dieter Schlüter's successful helicopter incorporating 'flybar' control of the rotor head.  However, though the head design was very simple in principle the first production kits were scale types which made them complicated and very expensive.  Schlüter did though take a step sideways in the mid seventies and produce a model which was a helicopter in name only and on the similar principle to the British Lark, produced the Heli-Baby which led the way for the 'all metal' 'pod and boom' models which were to 'globally' follow.

Kavan and Graupner followed in the 'Schlüter' footsteps of expensive 'scale' helicopters though they spent longer in developing them before they were released.

These were the big three German manufacturers of the 70's but there was to be a fundamental difference between them.  Kavan and Graupner were distribution companies and were quite 'conservative' in production with making a profit and reputation upper most; Schlüter on the other hand was a designer and even before a new model was in full production he had a few ideas already being researched.  Because of this he was to be the most prolific in models and revisions whereas Kavan and Graupner were to only produce a few further models but they were well targeted and generally aimed at the upper end of the range.    

In 'vintage' terms, German manufactured RC helicopters are covered by a number of sites and if you want to know more then it is a must to visit the sites below (Remember to activate your universal (read Google) translator first.....):-

Helioldie  -  Full of information especially concerning remanufactured parts, restorations and restoration techniques.    

The Heli-oldie site has many sub sites linked to it and so you can spend a happy hour bouncing around finding all sorts of interesting info. 

Heli-Baby  -  Web site run by Gerd Guzicki dedicated to the Schlüter Heli-Baby and including the new manufacture of the original Fixed Pitch Heli-Baby.

Schlüter  -  Dieter's own web site covering his current occupation and historic helicopters.

Cobra  -  Web site run by Uwe Jantzen covering the early Schlüter models Cobra, DS-22 etc.