If you haven’t heard of the Curta Calculator, see the wikipedia page for basic information and the vcalc.net disassembly for a look at the internals of one.I have been working on 3D printing a Curta Calculator for some time now. I am printing it at 3:1 scale and most of the printing is being done on a customized gMax 1.5 I built. I have one standard 0.4mm nozzle to print the larger parts more quickly and one 0.25mm nozzle for the smaller parts (it is absolutely necessary at 3:1 scale). I did all of the modeling based on the original engineering drawings.Currently the bottom portion of the Curta where most of the math mechanics reside is complete and functional. I’ve been working on the top portion where results are tabulated.Photo of the current stateI’ve been keeping progress for the project on my blog and the following is a list of my posts about the Curta: * Part I — Beginning the CAD modeling (in OnShape)Part II — Completing the CAD modeling and beginning planning (I initially thought I would try SLS)Part III — Estimating 3D printing tolerances for various mechanical fitsPart IV — Initial 1:1 scale trial with Shapeways and decision to go back to FDMPart V — First test prints of Curta parts; first working part (not going to be used in the final Curta, though)Part VI — My first real prints and experience cleaning support material off of large overhanging partsPart VII — More printing, assembly of the main frame, adding threads to printed parts, making springs.Part VIII — Finished the bottom portion of the Curta… and then broke the main shaft.The plan is for the ninth part to cover finishing the printing and mechanics of the calculator and the tenth post to cover painting and adding the lettering / numbering (it’s honestly not very useful without at least the numbering).Please ask any questions you have about the project. http://ift.tt/21US0iy
