Ivan Rogstadius: Swedish Model Engine Pioneer


We here at Model Engine News confess to an unashamed nostalgia for the Golden Days of model building and elderly model engines, especially those lovely, smelly, oily diesels. Precisely when this mythical Golden Age can be said to have occured varies with which of us is talking about it. Even though the period in question may vary, the excitement it invokes in our faded memories seems to be the same, hence our desire to document the engines involved, and to the extent possible, their designers, their development, and their builders. In most cases, this must be done by hunting down and interpreting old magazines and books. We try to get this right to the best of our resources, but your mileage, as they say, may vary. Examples on this site tend to come from the English-speaking countries and include pioneers such as David Stanger, HH Groves, Lawerence Sparey, Bill Brown, plus many others. Chances to get get first-hand information are few and becoming rarer by the year, so we are greatly pleased to be able to provide definitive information about another model engine pioneer, namely Mr Ivan Rogstadius, who in 1943, built Sweden's first "diesel" and provided fully detailed construction details for all, making him an "Open Source" pioneer as well.

The modern part of our story begins in a folder of information sent to me in Australia from the USA by founding Motor Boy, Roger Schroeder. The folder contained the plans for a spark ignition engine called the Schorder 09 which Roger had designed back in 1974, together with his research notes for the project. Amongst the sketches were three photocopied pages from a magazine series showing construction plans for a Dyno-like diesel. The name of the magazine was TEKNIK för ALLA and the series was titled HÄR KOMMER miniatyr-DIESELN. The n-generation photocopied pages contained no apparent publication date, although "1944" was clearly discernable in the text. Apart from schoolboy German and French, my foreign language knowledge is about zero, but a few seconds on the Internet plugging in words informed me the text was Swedish. So it looked like the article detailed a Swedish engine for home construction, probably circa 1944, based on the Swiss Klemenz-Schnek Dyno[1], the latter being one of the earliest and arguably most successful commercial compression ignition model engines which we commonly, if somewhat incorrectly, call "diesels"; the first being the ETHA[2], also of Swiss origin.

Some years ago, I'd drawn a set of 2D CAD plans for the Swiss Dyno which had been included in our original Motor Boys Plan Book. The Rogstadius 2cc appealed to me as an engine that could be easily hogged from solid aluminum in the absence of a casting and looked like a good companion subject for a 3D CAD plan set. So a model was constructed from the TEKNIK för ALLA drawings in preparation for generating the construction plans. But what to call it? Being too lazy to go through the process of converting the photocopies to text for submission to a translator, I sent a picture of the engine out to the Motor Boys to see if any recognized it. The first responses from Bert Streigler and Adrian Duncan remarked on its similarity in name and form to the Mikro-Diesel from Denmark. Then serendipity struck. Adrian asked his Swedish friend, Lars Gustafsson if he know anything about it. Lars was no only able to provide a copy of a 1945 catalogue showing the Danish engine, he did what we should have done and used the Internet to discover that Ivan Rogstadius was born April 24, 1915 and was not only still alive, but lived in Älvsjö, a mere 40km away!

This was exciting news. TEKNIK för ALLA, so Lars informed us, had been discontinued in 2001, but if he was able to talk to Ivan, we would be able, perhaps, to really discover and document the origins of the 1944 engine. So equipped with some questions, Lars phoned Ivan and discovered that despite his 95 years, he was active, alert, and would welcome a visit to discuss the engine and its origins. Here's the questions we asked Ivan through Lars, and his replies.

Interview with Ivan Rogstadius

Interviewer: Lars Gustafsson
Interview conducted on November 23, 2009 in Ivan´s home

How and when did Ivan create the published drawings?

In 1942 the chief editor of Teknik för Alla, Gunnar Fahlnäs, had somehow become the owner of a Dyno engine. He asked Ivan to make drawings using his Dyno engine as a pattern. The intent all along was to publish the drawings in Teknik för Alla. Ivan says he made the drawings in the winter of 1942/43 without changing anything in the original Dyno design. He then built his first engine for the purpose of testing its usefulness. A free flight model fitted with this engine was subsequently tested in Skarpnäck, a small air field south of Stockholm in 1943. A report of this test flight was published in the magazine Svensk Flygtidning number 7, July 1943.

Was Ivan the designer of the Mikro engine?

No, Ivan didn´t know anything about the Mikro engine that was produced in Denmark. But he noted that it was apparently identical to the engine described in his drawings.

Did Ivan have any contact with the Johansson brothers in Västerås who later produced the Västerås and Komet diesels?

No, Ivan had no contact at all with the Johansson brothers and he didn´t know anything about the brothers and their diesels.

Svedfelt & Co in Stockholm sold an engine called the "Typhoon" which looks like a Rogstadius engine. They also sold a similar engine under the name R-H. Does Ivan remember anything about these engines? Did the "R" in R-H stand for Rogstadius?

Ivan doesn't remember any Typhoon or R-H engines. He doesn't think that "R-H" means Rogstadius-Hellström. If his good friend Gösta Hellström had been involved in any engine production, Ivan says he would have known and remembered that. His drawings were published and thus freely accessible, and he had no way of knowing who might have subsequently made engines from them.

Did Ivan initiate any series production of the engine?

No, Ivan didn't initiate any production, but he built two engines himself from his own drawings, and a smaller one in half scale. Somebody built an even smaller version - Ivan thought that the bore was about 4 mm. Ivan said that it functioned OK. He doesn't recall who built it or know where it is today. Ivan thinks he gave his original drawings to somebody in Nyköping or possibly in Linköping. Maybe the person who got the drawings produced the engine and sold it through some hobby shop in Stockholm? Ivan has no knowledge of this. One of the two engines that Ivan built was donated to the watchmaker Gösta Hellström (a good friend of Ivan's), who built the free flight model which they flew together in Skarpnäck in the summer of 1943. He sold the other engine to a couple of boys in Stockholm. Gösta Hellström also built a boat for Ivan´s diesel engine. This boat was tested in the waters around Drottningholm Palace, outside Stockholm. The half scale engine is still in Ivan´s possession today. Ivan was not an aeromodeller, he was more focused on mechanical things.

The Danish Mikro-diesel manufacturers - what kind of contact did Ivan have with them?

No contact at all.

Does Ivan have anything left? Parts - engines - documents? If so, there are some customers who want to buy.

Today Ivan has the half-scale engine, and an engine which he built from a drawing in an American magazine. Ivan does not remember which magazine. This engine was built before he made the Dyno-copy, during the first years of the forties. Ivan even made the sparking plug for this engine. The crankcase was cast by Wedaverken in Södertälje. Ivan had a few made at a cost of 5 SEK($1) each, which Ivan thought was a little expensive. He sold a couple of crankcases to several other interested persons. A total of three of these "American" engines were built in Sweden to Ivan's knowledge, and today Ivan still owns the one that he built himself. He doesn´t know where the others are. Ivan´s engine was successfully run once when it was new, and after that it has never been started. Ivan has no engines, parts or documents for sale.

Was there any engine that was named Rogstadius?

No, not as far as Ivan knows.

In TfA it says Swedish made, but the Mikro engine was made in Denmark.

They were two different engines. Ivan´s engine was a Swedish Dyno copy. The Mikro was a Danish Dyno copy. Ivan had no contact with the Danes.

Was the Dyno popular in Sweden? It seems to have influenced early Swedish engines.

Not being an aeromodeller himself, Ivan doesn't know anything about how popular the Dyno engine was in Sweden.

When did the first Dyno come to Sweden? How long did it take until a Swedish Dyno existed?

The first Dyno in Sweden was probably the Swiss example mentioned earlier that Ivan took as the basis for his drawings. Ivan doesn't know precisely when or how that engine came to Sweden, but it was certainly in the country in 1942 Ivan developed his drawings before attempting any construction, and his first Dyno was constructed in the summer of 1943. As far as he knows, it was probably the first one built in Sweden.

Did Ivan have anything to do with the design or production of other Swedish engines?


Which engines were popular during the war, and after?

Ivan had no answer to this question.

Were model boats and model airplanes popular hobby areas?

Ivan had no answer to this. He was more interested in engines and mechanical things, not model boats and planes. His friend Gösta Hellström took care of the model building.

When were the articles published in the Teknik för Alla magazine?

In December 1943 and January 1944

Did Ivan ever sell his drawings to anyone?

No, he published them and then gave the originals to somebody from Nyköping or possibly Linköping, Ivan doesn´t remember which - it was 65 years ago! He received a question from the USA asking if he could deliver engines to the USA. Ivan's answer to this question was no - he never had any aspirations about going into series production.

Model Engine News thank Ivan, Lars, and Adrian for their generous contributions of time and effort to capture this little piece of history which we can summarize as:

  1. In 1942, the editor of Teknik för Alla somehow managed to get hold of an actual Dyno. This would have been no small accomplishment, given the state of war-torn Europe at the time.
  2. Using this engine, Ivan made his drawings in the winter of 1942/43. Shortly after their appearance in Teknik för Alla these drawings and the construction details also appeared in Hobby-Boken, resulting in very wide coverage, given the times. This was the trigger for the flood of Scandinavian Dyno clones of which the previously mentioned Mikro-Diesel was one.
  3. The prototype engine was tested in the summer of 1943. An article on the tests was published in the magazine Svensk Flygtidning of July 1943 (the Swedish equivalent of Aeromodeller, or Model Airplane News). This was Ivan's first published appearance.
  4. Ivan had nothing to do with the Danish Mikro, nor Komet engines, although he agrees that they may well have been based on his published drawings which were freely accessible for anyone to use. As far as he knows, there never was an engine marketed with his name attached and is not at all troubled by this; he made the drawings and wrote the article to enable others to build their own model diesel engines. In effect an original Motor Boy!
  5. Ivan himself was an engineer, not an aeromodeler. His interest was how the engine worked and how others could duplicate it. The model mentioned above was built by Gösta Hellström and powered by Ivan's prototype 2cc diesel. Ivan later worked for Ericsson with fibre optic cables and filed a patent in 1982 on a method for obtaining an accurate concentric fastening of an optical fibre in a connector (see patentlens.net).

See Also:


[1] See The First "Diesel", Model Engine News, February 2005.
[2] See The Last Word on the First "Diesel", Model Engine News, April 2008.




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