> There are machines out there today for smaller parts that will use wire deposition like this to build the bulk rough outline of the part then machine away the

> There are machines out there today for smaller parts that will use wire deposition like this to build the bulk rough outline of the part then machine away the rough outer layer for a precision part. Right, so all you're really saving is the first rough cut, which is normally pretty fast anyway. (And the chips can be recycled.) But now you also have to live with the material properties of welds, instead of a high quality, grain-oriented piece of forging stock. And you also have to move the part from one machine to another, then re-register it (dial it in to make sure the build is oriented correctly in the CNC machine's coordinate system). Not as bad for the hybrid machines which can do both operations, but still not great. Back to this bridge: Without post-processing by grinding/sanding/smoothing, you're reducing the material strength due to increased localized stress concentrations. This doesn't matter much in stiffness-dominated structures, but significantly reduces the performance for strength-dominated structures and structures which experience a lot of cyclical loading. I just don't think this is terribly scalable. Neat art project, though. EDIT:If you want to automate things, I think it probably makes more sense to automate using more conventional building methods... Cut standard beams to size, place and weld automagically, etc. It'd be much faster..... Like this: https://www.youtube.com/watch?v=rD9__jheNLg https://www.youtube.com/watch?v=rD9__jheNLg