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Some ideas and thinking about truly practical printers (especially putting printers into the big picture).

Posted by GreenAtol 
I came across the reprap project a couple months ago and have been thinking on and off about the stuff, especially how it might fit into the larger world, and the future of printers. Here's some of my more interesting thoughts on printers in general:

You often hear and read people saying a printer or say a fab lab can make "almost anything" and "at the cost of materials".

And there are some real issues with those statements: when you start asking yourself what, of the things around you you can
make, it quickly becomes obvious that that's a bit of an exaggeration. And the materials themselves are the product of human labor, just like products so why do they get special status?

I think this all gets much more interesting when you try to put it all in perspective:

Bob talks about precision machine shops as a sort of self reproducing printer. If we expand the definition of printer to any piece or collection of equipment - such as a fab lab with the associated operators - that can produce usable real world physical goods then things get a lot more interesting pretty fast.

Humanity already has a self reproducing printer that can make literally anything in civilization, which consists of all manufacturing equipment on the planet plus all the human operators. Let's call it the Complete Existing Printer for now. Economics is pretty complicated, but it might be fair to say that this is the only manifestation that we already fully know how to do which can make everything in civilization *at the current prices we see on the market*. Although there is no doubt that a better printer is possible, which can make a wider variety of stuff more cheaply. Particularly because we have things like planned obsolescence and other features of the equipment, organization and end products which are inserted by counterproductive people on purpose and would be easy to do away with, providing large gains.

The variety and sophistication of the end products that the CEP can produce includes all materials, everything form Boeing 727s to spoons and semiconductor components, food etc. In a recent ted talk Tim Harford points out there are supposedly 10 billion distinct, different products available on the market for sale in New York City, for instance, so presumably there are many more elsewhere.

But what is the size of the printer? And how large and expensive is the share of it which is used by a single person in the developed world? I mean it can only be so expensive when you get right down to it because the total of society's infrastructure is owned by people (shares in corporations often), and the average person is not that wealthy, and the material goods production infractructure is a small fraction of that.

Then, if you look at the smallest (in terms of capital cost) fraction of the system which - in isolation from the rest of the world - could produce say the 95 percentile or say top 5000 most economically important products at a price that is no greater than 20% of the market price for instance, and is still able to make itself, I bet that would be far smaller in terms of the amount of equipment needed because you do away with the million different types of merlot and so on, let's call it the Smallest Practical Almost Complete Reproducing Printer (SPACRP). Let's suppose we stick only with the type of technology, and costs measured as the current market price of the stuff, that is already being used. (Just a side note though that it would probably be really hard to predict what monetary prices of the produced equipment would be, so maybe it would be better to measure cost in terms of personel-hours and equipment time or something)

First of all there were many redundant components in the Complete Existing Printer. There are a great number of precision machine shops in the world, but the SPACP only needs one. Secondly, there are many production methods like injection molding that only exist to reduce the cost - for example pretty much anything you can make by injection molding you can machine directly, so some of those production methods would not be needed.

Thirdly, removing the 5 percentile least important products would probably greatly reduce the variety of stuff it needs to make, simplifying it. Would be extremely interesting to know what this printer would consist of.

The components of either the CEP or the SPACP could be arranged herarchically in terms of what you would use to make and maintain what - a CNC mill might be used to make a telescope but not vice versa. In many cases though the relationships end up coming full circle, you can make something with a mill which is part of the equipment you would normally use to make or maintain some part of the mill. Like a machine to make ball bearings, or a screwdriver to help assemble and maintain the mill.

Now imagine you take this further with a chart that showed all the relationships and dependencies between the different peices of production equipment - the ecology of equipment basically - remember it includes "land" as a sort of peice of equipment needed to produce food, chemical engineering plants needed to produce the raw materials like steel or plastic, etc. So it's not a tree, it's a very complicated chart although you might arrange the elements on the chart so the peices with the most stuff depending on them are at the bottom, like prey at the bottom of the food chain. And because it would end up including all the important stuff like housing and food and computers this SPACP could probably be the material basis of a pretty good economy.

Once you knew what it was there are probably a ton of places to step in and optimize it for what you want, especially if you are permitted to increase the net cost of producing some products by eliminating more of the cost-reducing-only production methods, or by tinkering with the design of the produced products and production equipment (which are themselves also products because it can make itself) to make them easier to produce with a smaller set of equipment and relatively few people and/or people who have less training.

In many cases you have a chemical plant or whatever and you might want to break it down into pumps, tubes, etc. (but with a border around those parts still) and represent it on the chart like that, which would make it more visible what parts of, say a ball bearing production machine, requires a lathe to produce. It might make the chart have less distinct elements in it, too, if you did that for all equipment, so you can see the number of particular types of parts involved which might be nice. It might be interesting to break it down into the individual moving parts of all the equipment, or in terms of the regions of the equipment that consist of homogeneous materials - so a painted peice of steel would be broken down into the paint layer and the steel - or various other things.

It might be kind of cool to visualize it as if it were displayed on google earth as an actual implementation of it, with the aluminum mine in one place, the steel mill in another, the machine shop somewhere else. Then click go, and it starts producing things, transporting aluminum to the mill to be converted from billet into sheet, then to the machine shop and so on. Each time material is moved you could draw a trace between the origin and destination, which had a few numbers displayed next to it that describe the person hours, whatever, that have been put into the transport process and the object being moved, or the value added after the last step or something. Maybe a number floating next to the destinations could indicate their cost similarly.

Also in many cases the production equipment will be jigs or assembly lines needed to assemble an airplane or whatever which are specific to particular products but do not produce other production equipment. You could try excluding those so you end up with a sort of nucleus which is not itself capable of being an economy, but which could produce one given enough time and resources and good plans to follow (which is where open source would really help).

Also, when I say end products, almost all parts of the printer are also probably end products that the printer can make even if you did not deliberately include the "can reproduce self" criteria, as they will tend to be highly economically important, and almost all end products are also production equipment in way - the operators could wear the clothing they produce for instance. There may be some end products that are luxuries like wine or something that are only used very slightly if at all in the production process I guess.

You could further whittle down like this the amount of equipment and training needed to make a new model of printer you could call the Optimized Bang For Capital Expenditure Buck Printer. You could also try to reduce or eliminate dependency on remote mines or people that may not be there in the future, or whatever you want to.

Or even further whittle it down until you get the Printer That Costs Less Than $70k And Also Gives The Best Bang For Those Dollars Printer. The best bang in your view anyway. Or you could try to make the printer that had the least elements in the chart that could produce all the same products in isolation from the rest of the world, while allowing for price increases. There are lots of interesting things you could do with it.

At this point we could put fab labs, and the reprap and other new types of equipment or methods, in perspective easily. We can look at the SPACP or the PTCLT7AAGTBBFTDP or whatever your desired printer is, and see what peices of equipment the new kid on the block can replace most or all of the functionality of, and what, if you subbed in the new equipment for the old, the effect on the cost(s) of the products produced will be.

Often, when you are talking about say a RepRap, you want to know what vitamins it requires, and what sort of objects it can produce, what sort of effect it might have on the world. This approach of looking at a giant chart - an ecology of production equipment represented on paper - makes it easier to see the answer to those questions and put the capabilities of the RepRap model in perspective with the rest of the world, and the current production methods and equipment our economies already tend to use.

And also what it can make that the SPACP cannot, but let's face it, what humanity really needs is not so much different stuff or new types of stuff, but the capacity to make the stuff we can already make much cheaper, and secondly to actually use that capacity effectively for the right things, rather than what happens when it is in the hands of the bankster type people.

Then you could consider the importance of different types of theoretical new types of printer based on how they could change your main printer, like the CEP. The capabilities could be thought of in terms different resolutions and with different accuracy (and it's really accuracy that we ultimately want, not precision) and materials, and printing speed. There is the printer that can print in only one material to 2 micron accuracy or so with several micron voxels, like a direct metal laser sintering machine, and we already have those but they cost too much right now. There is the printer that can print something with a small range of materials in any desired voxel. There is the printer which can put whatever material you would like in any voxel (volume pixel). Then there is the molecular assembler, which is like a super high resolution of the latter because it can make something with atoms placed wherever you want. And you could go even further to subatomic particles I guess.

There would be many variations in between and probably a lot of practical printers, certainly the early ones, will be somewhere in between. Suppose a 2 micron voxel 1 micron accurate 3 material printer could also control some of the metallurgical properties of the metal it was depositing for example, like temper some areas of a high carbon steel part. That is having limited control at an atomic level but with similar or likely lower resolution. Or it could control the properties which the boundary between different material voxels had - a strong bond or a very weak bond, which essentially the ability to exert limited control at a low level.

In practice, at first, there will likely be many different limits on the printing capabilities besides voxel size and material types - you may not be able to get as high a precision for where exactly the boundary between 2 different materials on the workpiece is as the precision for where the boundary between a single material and the air (or surrounding vacuum or powder bed) is. It may be possible to define the boundaries of your object to within say 3 microns, but the radius of curvature may be more limited - due to the inertia of the galvanometer mirrors for example. Or the rate at which the intensity of the laser can be modulated may produce limitations of it's own for another example.

Or maybe you could control the orientation of the molecules within the voxels, so you could produce a material like Dyneema from Ultra high molecular weight polyethylene, Dyneema is a material in which the UHMWPE molecules are mostly aligned lengthwise along a particular axis, making if far stronger along that axis. Or the orientation of fibers in a composite material maybe, but most composite materials have fibers bigger than 1 micron, so you could also print a composite material like glass filled nylon directly. Except printing say a glass directly adjacent to a plastic (after the plastic) might be problematic for the heat-sintering sort of approach because the melt pool temperature of the glass is too high for the plastic to stand without burning.

Edited 3 time(s). Last edit at 08/09/2011 03:00PM by GreenAtol.
Re: Some ideas and thinking about truly practical printers.
July 29, 2011 03:13PM
Practical is what is doable with current engineering principles.

You can think about it this way:

Lets see what would be "ideal" and whats the next best thing until we approach something which can be built.

- Santa Clause Machine
- Startrek Replicatorâ„¢
- Molecular Machinery (Would need support material for some objects, free software already exists: [www.nanoengineer-1.com], implementation is far away)
- Controlled Vapor Deposition Techniques (only few micro scale, low complexity things had been built in academia)
- Electron Beam Melting ( potential for 99% replication, commercial machines are available. Practical accuracy only dependent on raw material, theoretical as good resolution as any SEM, see MetallicaRep [forums.reprap.org])

Then practical is what is affordable, and can be self-replicating.

Things like Selective Laser Sistering and Stereo Lithography may be superior to FDM but need more components which it cannot make by itself, meaning the increase in quality does not justify the increase in complexity, at least right now.

We will probably never be able to sinter a laser tube with a laser.
We will probably never be able to print a uv light emission device with stereo-lithography.
On the other hand the potential for FDM to increase its self replication ratio is there because it can be adapted for many different materials and is low tech.


Self replication will probably never be perused by large commercial interests because it goes against their philosophy, so when it happens it will happen outside the current system anyway.

As for independence from raw materials, that is something we will probably reach at last since it is at top at the list (the santa claus machine, even startrek needs dilithium). But it all depends on what we use. sintering sand by whatever method is really straigt forward for example, but obtaining a pure material always requires effort.

The alternative is to construct "printable" machines which can be used to make raw material out of resources, machines which can be "printed" and be used to build parts of the printer. (For example a cnc router, cnc lathe, use the lathe and router to built a glass blower -> selfmade CO2 laser)

imo such support machinery and a method for supportive replication will be a very important thing in the near future.

Edited 2 time(s). Last edit at 07/29/2011 03:34PM by ElectricMucus.
Re: Some ideas and thinking about truly practical printers.
July 30, 2011 03:34AM
The idea of making a list of the whole resources available reminded me the last part of the 3rd Zeitgeist movie (in which Adrian appear btw ^^).

"III Project earth" (a resource based economy, with a systemic approach)
If you didn't saw it : [youtu.be]
Re: Some ideas and thinking about truly practical printers.
July 30, 2011 06:19AM
Re: Some ideas and thinking about truly practical printers.
July 30, 2011 03:01PM
The thing is, if you think about it, consider the ecology diagram for the CEP printer. Now add a DMLS machine if it wasn't already there. Now suppose the relationship connections on the diagram are changed so they no longer indicate just what is *normally* used to make what, but also what *can* make what. It would have really a lot of connections on it because there are many ways to make any given product, many different paths you can trace with your fingers to get from one product/piece of equipment to another.

Normally a lathe is probably not used in the process to make a CO2 laser tube, because it is too expensive, but it can be. A DMLS machine is not normally used to make the sort of things a lathe can make, but it can make nearly any metal part a lathe can make (within size limits) and this spankin new diagram would make that visible.

Now suppose you find the shortest possible path (in terms of the number of pieces of equipment along the way) between say a hammer and a CNS milling machine and color it purple. Then do the same between all other products. Delete any connections that are not purple because they are not needed for the shortest paths between products.

If you follow the connections on the diagram, which indicate what equipment depends on what, within one hop i.e. to all the adjacent pieces of equipment, and then again for each adjacent piece of equipment (so a distance of 2 hops from the DMLS machine) you can then draw a line around all that equipment and call it a printer if you want. But don't do that yet.

Now simply find "CO2 laser tube" on the diagram (assume the DMLS machine uses a co2 laser though I know a lot use a fiber laser you could probably make one with a CO2 tube). Now follow the connections on the diagram which indicates what production equipment is needed to produce the laser tube, one hop, two hops etc back, all the way back until you reach the DMLS machine. Probably only a few hops I bet.

Now, some of the equipment that you hopped to will be stuff like a machine to make screws or something. Well, we can buy screws cheaply so we don't really need that machine. Eliminate all those such machines. Now, draw a line around all the equipment needed to help get you from DMLS machine to the laser tube, and call that a printer.

Now you have a printer that can print a laser tube. The question is what the capital cost and running cost of it will be.

Secondly, instead of sticking with the machinery that you inherit from the CEP, you could instead start with just a DMLS machine and make your own, single, custom *printable* widget which combined with the DMLS machine allows you to make laser tubes. Probably it would be a machine to make the mirrors and lenses and maybe align them, and the DMLS machine would make the side walls of the tube? Maybe it should be a machine that is not a Direct Metal Laser Sintering machine per se, but can also sinter glass to produce a glass tube.

Simply draw a box around the custom widget and the DMLS machine, call that your printer and now you have a self reproducing printer that can print laser tubes. Same deal for a UV light source.

Edited 2 time(s). Last edit at 07/30/2011 03:36PM by GreenAtol.
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