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The 2004-model is the largest mobile model until now; a 1½-Deck-Bus in approx. 1:10 scale.
The 1½-Deck-Bus in the sixties and seventies ran in many regions of the northern and middle Germany. It was available from different manufacturers like Büssing, Krupp and Mercedes-Benz; also from Henschel and Faun some single vehicles could be found, and since 1971 Büssing was replaced by M.A.N.-Büssing. But this companies only delivered the chassis; the body was built up by the Ludewig company in Essen and under license by the Vetter company in Fellbach. The following picture shows a typical bus of this type. (Nearly) all busses had e. g. two rear axles, from which the anterior was driven and the posterior was a trailing axle.
This variety was not unfounded: The interior equipment was manufactured customer-specific, and that resulted into a lot of different seat arrangements. On the other side this bus original also had a conductor; so the entrance was behind and the front door could be comparatively small. In course of time the conductor was abolished; thus the back entrance could be smaller resp. could be omitted, and now the front door was the entrance and had to be wider. The rear area of the bus then usually was equiped with seats. Prior to the mounting an intensive planning and construction on paper occured to appraise the expense of material and above all the weight; moreover in this way one gets a good idea of the appearance of the model. So the time of mounting was relative short and the required material could be purchased only with a few orders. Because of the numerous variants it is nearly impossible to build an authentic model, bur for a metal kit model this is secondarily. The base of the model was a Mercedes-Benz bus O-317 because this type was in remembrance passably and because of this type most pictures could be found. However the interior - and especially the upper deck - firstly was a problem. But near completion fortunately some plans of the interior equipment were provided and so the model could be finished satisfactory.
After getting on through the back door one stood on the lower deck, where an adult still was able to stand erect (height approx. 1,90m). Opposite to the door transversal to the driving direction was a seating bench for some persons. The benefit of this was, that the floor of the upper deck in the seating bench area could be lower for approx. 25 to 30cm. In this way above a gangway height of about 1,80m was possible. On the lower deck level between the wheelcases of the trailing wheels one passed the conductor. While passing a step one reached the main deck of the bus; now one was located exact above the driving axle. At this place the upper deck just ended, otherwise one would have bump his head agains it. This shows that the upper deck could not be used in this way the exterior view of the bus suggested; between the rear axles the upper deck had to end and itīs length not even was a quarter of the total length of the bus. Nevertheless the upper deck generally provided 17 additional seats. Especially at this model the modular design again proved to be advantageous and necessary, because otherwise some areas would not have been accessible. Beside the interior the model is provided with spring suspension, Ackermann-steering, motor drive with differential and of course radio control. Also the doors are to be opened, whereby the front door corresponds to an folding door. The rating of the springing occured in the way described also on this site. For this after completion the axle loads were measured by means of a spring balance and this basis the different springs were calculated. The mass of the model is amounted to approx. 16kg; from this weight the rear wheels carry 9kg and the front wheels 7kg. Because of the distribution of weights and the diverse wheel suspensions 4 different springs with spring rates between 1,7 and 3,5N/mm are required, which however could be made from one semifinished product. The steering of the heavy model is operated from the steering wheel via a relative great reduction with MEKANIK gears; the use of a worm gear is not possible, because the steering wheel shall move with the steering servo. For steering on a solid ground a torque of approx. 50Ncm is necessary; for that reason a miniature servo with a torque of 75Ncm is used. The steering trapezoid is designed in this way, that the extended track rod arms are intersecting between the rear axles. As motordrive the selfmade and proved drive unit is used. On one side it is free suspended in the driving axle, and on the other side it is movable supported; so it unchecked can follow the movements of the springing.
Also balustrades and grap handles are imitated. For this anodised aluminium with a diameter of 4mm is used and this comprehensive corresponds to the original. Steering Suspension of the front wheels Suspension of the rear wheels In spite of the heavy weight the radio controlled motorisation seems to be possible without problems. However critical are the wheel suspensions which are twisting because of the load, and that results into an unbeautiful camber inclination; hence all suspensions are adjustable and can be accommodated to the weight. In June 2004 the drive shafts were upgraded with miniature ball bearings.
The 3/2005 (April/Mai 2005) edition of the "TRUCK modell" magazine contains a complete report about the 1½-Deck-Bus. The reproduction of the front page of this number as well as the first page of the report by kind permission of www.truckmodell.de
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