In the early 90s Peter Rospert planned an own airplane project: designing and building a nice metal aircraft. Time went by and the start was delayed from one year to the other. So he started to create at least the variable pitch prop for its project.
The new high performance UL-aircraft generation also demanded for a VPP in combination with that brand new Rotax 912 engine. To vary the pitch a pushpull-rod was installed through the hollow engine gearbox shaft. A scissors type actuating mechanism connected to the rear of the gearbox. In the beginning a hand crank operated it.
Later this was replaced by a linear actuator. Even a constant speed device was soon available. Eventually three bladed propellers were designed and two different blade makers provided their products:
Glass composite and carbon composite blades in different shapes for different purposes.
The blades are fully interchangeable and every kind of Neuform or Helix blade can be installed on the Rospeller hub. Replacement of a damaged blade is a job of just a few hours.