Building Babbage's Analytical Engine 56
An anonymous reader writes "Anybody think 3-D printing technology will have enough moxie to pull off a construction of Babbage's analytical engine by 2021, the 150th anniversary of Babbage's passing? The Guardian reports, 'Plan 28 – named after one set of Babbage's plans – has assembled the leading technical experts on his designs and just started fundraising. The first stage of the project involves studying the thousands of pages of handwritten notes that Babbage left behind, to determine what exactly needs to be built. Once the study is complete, we'll be building a 3D physical computer simulation of the analytical engine to verify that his design is workable. Reaching that stage is likely to cost about £250,000. Only once the feasibility of building the machine has been established will the much larger fundraising effort needed for the actual construction to begin. But what we hope to do is create a working monument to the man who conceived the computer, and to inspire today's scientists and engineers to dream a century into their future.'"
Re:It's not hard to do, just moderately expensive (Score:5, Informative)
You are quite correct that we have not built a single demo part. In the two years since I started talking about this project the following has happened:
1. Persuaded the Science Museum to digitize all of Babbage's plans and notebooks (this in itself was a non-trivial task involving a great deal of effort at all levels and they should be thanked for taking on the task).
2. Got the leading Babbage experts to join and work with me (Doron Swade who built the Difference Engine No. 2 and Tim Robinson)
3. Started a UK-based charity (again these things take time as there are legal requirements and the recruitment of a board of trustees)
4. Started research on the Babbage archive itself
5. Begun fund-raising.
No. 4 is non-trivial because there are literally thousands of pages of notes and > 230 large scale plans to decipher. Plus there's a hardware description language to work with. And the archive is not well documented. There are a number of different cross references that conflict with each other. I realize that all this stuff is boring and people would like to see an immediate result, but that's not going to happen. It's years of work to properly study this stuff and build a historically accurate machine.
Note that we have not proposed building the 1,000 memory location machine. That's far too much to demonstrate that it would work and would add to the cost and size. As for the number of parts, until we've deciphered all the plans and come up with a definitive plan that it's hard to answer but we believe there will be roughly 40,000 to 50,000 components to be made.
Re:Already underway (Score:5, Informative)
Tim Robinson, the man behind the Meccano construction you link to, is a trustee of the Plan 28 charity mentioned above.
Re:It's not hard to do, just moderately expensive (Score:4, Informative)
Not to mention that an analytical engine made in 3d-printed plastic (ABS, nylon, etc., depending on the specific technology) probably wouldn't work. Back in the day I designed the mechanics of a grandfather clock in CAD. On a lark, I got to go-ahead to print off a number of parts on the school's stratasys (an FDM machine that extrudes hot ABS). When I started putting things together, I realized that the project would not work very well. The surface finish and dimensional tolerance made for high friction and occasional binding. Plus, the cost of most of these parts was really high - several times the cost of mass-produced gears from, say, stockdriveproducts.com [sdp-si.com]. So, instead, I scrapped the fully custom design I had been working on, and remade it using slightly different-but-vastly-higher-quality-at-lower-price parts available off the shelf.