Development of the Rubin model

Background to development of the Graupner Rubin model

(adapted from a post on the RC forum by “Thomas MMGER 15”)

Development of Rubin started back in late 1990. After taking part at a Naviga championship I visited Graupner and Mr. Hans Graupner asked for a new sail boat to follow on from Optimist 1-ton model created in the late nineteen sixties. I started to generate some suggestions and it ended with Rubin. In those days the yachts from our former DSV president Hans Otto Schümann were well known and yachts to the former IOR rules were also common on water, such as Optimist in earlier days, or the model of Saudade from mid nineteen seventies from Hegi (later Revell-Hegi and Wedico).

I came into contact with Friedrich Judel in Hamburg, one of the two designers of the original (Judel & Vrolijk Design). He suggested hull lines from a more modern boat built to the new IMS rating which would have given a better sailing model, as these hulls were not as beamy as typical IOR hulls had been. In some aspects more closer to what Marblehead hulls had been. But as there had been no famous Rubin to those new lines it was decided to use one of the successful and well known IOR boats – Rubin (whose sister-boats were Pinta and Outsider).

He made a special scaled down hull drawing of the VIII (or VIX) boat with won in 1985 the Admirals Cup with the German team and hence won some popularity. As the original IOR-yachts were very beamy, scaling down with unchanged proportions would not generate a really good model boat, so the model lines were modified to a less beamy version. That’s why Rubin is about 100mm less in width than the scaled original. Also the underwater lines were modified for better water flow as the very characteristic IOR-rating hull “buckle” at the rudder was not scaled down.

From these lines Graupner workers made a first simple hull plug from wood and sent me vacuum formed parts to create a first prototype for testing sails/keel/rudder arrangements.  A full size display model was also made out of balsa – something Mr. Graupner used to get his own impression of the new model which he was not able to get just from drawings. It also helped to find some faults here and there in the proposed proportions. All in all it took two years to get the boat as kit to the market.

In those past times I was more or less satisfied with the result (even though there are always some things which could/should have been made different in kit boats, and I never get one of my own kit boats really 100% to my eyes).  However today I would not make this boat again. Not using such an original as the basis and not in the way the kit was made and the boat is constructed. I think it was much too complicated for the customers to build and also to sail.  In addition there had been quality problems over all the years, for example with the laminated parts which came from several suppliers. The fins were often somewhat too thick and therefore difficult to fit into the integrated box in the hull; also the hull quality varied sometimes badly.

During later production times the sails were made out of too thick material as the (good) sail maker could not get thinner material except for simple spinnaker cloth, and a sample made out of that was worse than the thicker material in my eyes. That would not have been a big problem if the whole mast/rig layout would have been a different one, a more conventional version without the need for bending. Like the one Robbe used on their Smaragd which is much easier for customers to use. Rubin is kind of a diva, a yacht which required some experience and skills to get the potential out of it. In that aspect it is true to scale to the former IOR yachts,-)

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