Well I have started to model parts for the Curta!  It's kind of cool using drawings you can tell were drawn by hand....not something you ever see now.  I think I will be able to just machine this guy out of aluminum on the cnc with some creative way to hold/locate it from setup to setup.

I also started buying a few pieces of aluminum and brass to test out fits and play with silver soldering.  I think that might be how I attach the tiny gears to all the sleeves....

VCALC.net is the best place to go for info on the Curta and the more you look the more you find....  The simulators have been key to understanding what each bit does.  I am slowly going through the 'Curta Disassembly' slides and it is both a super good explanation of each part and a crazy look at how small these parts are.  Holy crap!!!  I am going to have a hard enough time making these parts at 3x scale!

Well, I have been bitten by the Curta bug and now I have to build one...  If you don't know, the Curta is the most successful handheld mechanical calculator in the world and has been obsessed over by engineers, tinkerers, and mathematicians since it was invented.  The complete backstory and latest info on it can be found here.  link

The parts are so small that a 3x build makes more sense, especially because Marcus Wu(in pic above) has already done some of the leg work and modelled and 3d printed one at this scale!  I will definitely be standing on his and other's shoulders throughout this build, but there will still be tons of work to do. 

As you can see, I have already pieced together the assembly from Marcus' stl files, now I have to go through every part and redesign it in Solidworks to be made how I want/need to make it!

I want to keep 3d printing to a minimum, use the tools I have, and maybe learn some new skills to make the pile of parts that will be needed.  Marcus' 3d printed Curta is beautiful but I want this one to be primarily made of machined or cast metals and plastics to make it more durable and in line with my design aesthetic.  The main goal will be to showcase the mechanisms that make the Curta work, so I will also probably leave off most of the external shell.  ​

As things progress, let me know what you think or if you have any suggestions!
Thanks,
​Chris