Curta Type I

This is my model of a Curta Type I calculator produced from the original factory drawings , everything is included in the drawings so I was able to complete the whole model with only a few problem areas, main problem being item 10070 which may be beyond my expertise or software used Software used was Fusion 360 which did a great job but the free version is limited in the type of CAD export that can be done, I could possibly do other formats at work if anyoune was interested. History from wikipedia. The Curta was conceived by Curt Herzstark in the 1930s in Vienna, Austria. By 1938, he had filed a key patent, covering his complemented stepped drum, Deutsches Reichspatent (German National Patent) No. 747073. This single drum replaced the multiple drums, typically around 10 or so, of contemporary calculators, and it enabled not only addition, but subtraction through nines complement math, essentially subtracting by adding. The nines' complement math breakthrough eliminated the significant mechanical complexity created when "borrowing" during subtraction. This drum was the key to miniaturizing the Curta. His work on the pocket calculator stopped in 1938 when the Nazis forced him and his company to concentrate on manufacturing precision instruments for the German army.[2] Herzstark, the son of a Catholic mother and Jewish father, was taken into custody in 1943 and eventually sent to Buchenwald concentration camp, where he was encouraged to continue his earlier research: While I was imprisoned inside Buchenwald I had, after a few days, told the [people] in the work production scheduling department of my ideas. The head of the department, Mr. Munich said, 'See, Herzstark, I understand you've been working on a new thing, a small calculating machine. Do you know, I can give you a tip. We will allow you to make and draw everything. If it is really worth something, then we will give it to the Führer as a present after we win the war. Then, surely, you will be made an Aryan.' Fo