Boeing727

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Does anyone have information relative to Klaus (?) Stegmeir's radio gear produced in the mid to late 50s ?

The servo system was totally unique in that it was pneumatically driven - with the air supply provided by a Boxer Twin engine -- to a holding tank and then out to the individual servos as required.

In operation it seemed to be relatively flawless - but extremely demanding as regards upkeep.
Stegmeir produced the electronics as well and managed to compete at world level during the 50s......and then (apparently) disappeared.

Any info appreciated .

ukengineman

I have a photo of one of his models with the top removed showing the installation of the pneumatic control system and reservoir tank. You can also see the Rupert Boxer twin you refered to. I can post the photo if of interest to you, it was certainly the most unusual of control systems. I suspect the system may have been commercial available as I have seen a number of the Rupert Twin engines with the pneumatic pump on them to drive the servos.

Boeing727

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thanks !
The system worked extremely well , as did the Boxer Twin -
Steigmier DID produce the gear for commercial use and I believe the R/C side of the business was both a proving ground as well as a personal issue with the designer.
I've seen the hardware/software and it appears to have been designed and constructed to military specs at least !
I attended a world class event in Darmstadt, Germany about 1957-58 and it's performance , for that period , was light years beyond anything on the American market.
Stiegmier was a young guy then and his attendance was something memorable in that he arrived with a small trailer and a pro MECHANIC -- ! He flew dressed in business attire and his "mech" did just about everything !
I'm simply curious as to whether he is still around and what happened to the design ! His pneumatic drive system was surely original!

ukengineman

I suspect many people reading this thread will wonder what Boeing727 and I are talking about as this was such an unusual German R/C system produced in small numbers a long time ago. The reservoir tank was essential to keep a reserve of air pressure to power the servos in the event of the engine stopping. In the history of model radio control this system was to prove to be a dead end, yet in its day in the hands of Stegmaier it was successful at the highest level of international competition. I have attached the picture I refered to of one of Stegmaier's models with the top removed. You can see the pneumatic pipes and the reservoir tank, the Rupert Boxer Twin was a 10cc diesel with a built in pump to feed the reservoir tank with pressure.

Holderlin

Great info, sadly only in German:

http://www.modellflugsport.ch/upload...te_Nr_6_05.pdf

ukengineman

That is a very interesting article, I have never seen a close up picture of the transmitter or pneumatic parts before. I always assumed the system worked on pressure but it was in fact a vacuum system according to the article. I have had a go at translating the main body of text. I think I have got the general sense of it correct:-

"Karl Heinz Stegmaier may be one of the outstanding remote control manufacturers from the 1950's in the history of R/C. He spent several years designing systems and also entered in competitions. Thus he won from 1950 the German Championship ten times in succession. He reached his zenith with first place in the Europe Cup 1957, and with the third first place in the Aerobatics World Cup 1960 in Dübendorf. After that it was quiet from him and his remote control. His "pneumatic system" worked with the aid of a vacuum pump attached to a Ruppert/Webra Boxer diesel motor of 7.6 cc. The vacuum was stored in a negative pressure reserve cylinder. A complicated valve set steered the vacuum to diaphragm units, which worked directly as servos. If the engine stopped he had to land fast before the reserve cylinder had no more vacuum.The Stegmaier systems are very rare and few exist. The photographed installation was only found some months ago after three years search in Germany"

ukengineman

As a follow up to this thread about the German R/C pioneer Karl Heinz Stegmaier and his unique pneumatic system of servo control I have just discovered
this Movietone Newsreel footage from 1954. The last model which does two loops is Stegmaier's and the film shows the man and his Tx.
http://www.movietone.com/N_search.cf...ultsPerPage=10
If the long link does not work search for story number 61990 at http://www.movietone.com/
You will have to register to search.