This Gakken kit is the smallest of the Rotary Engine kits, but it is a nice little replica of an early
Mazda 12A engine.
The model was originally made by Gakken, but was soon after reboxed by the Entex trading company.
In 1997 Minicraft revived this model kit in all its glory, so back then there was no more need to pay collectors prices for an old Entex or Gakken kit if you wanted to own this model.
However, over the years the price of the Minicraft kit has krept up to a level beyond what the older releases sell for on eBay, so nowadays it pays to look around before buying the Minicraft kit.
In this kit emphasis was placed on making the completed model 'work', a small electric motor drives
the eccentric shaft and small light bulbs, representing the spark plugs, blink when the spark plugs are firing.
The shift lever acts as an on/off switch for the electrics.
The gearbox holds a clip for two Penlight (AA size) batteries. If you plan to run the model often, it would be better to extend the wires and use an external battery clip as changing the batteries requires removing the model from its stand and opening up the gearbox every time.
The small size and the electric motor mean that the moveable parts in the engine are simplified, for instance there are no planetary gears in the rotors, instead the housings side walls 'bounce' the rotors around.
The model comes in clear and multi-colored plastic and the gear box casing is factory painted in aluminum color.
The Entex trading company reboxed the Gakken kit and added a nice booklet
about how the real rotary engine works.
This Entex kit was sold in large quantities during the early seventies.
In 1997 Minicraft rereleased the Gakken/Entex kit. They did a great job: all the
mechanical parts are still in perfect shape, so assembling the kit and making things
work is easy.
In 2001 Minicraft revised the box art.
Catalog number and kit contents remained the same.