3D Printing

[Paul Pless]

I heard a fascinating segment on 3D Printing yesterday on NPR.

One of the comments that I found most intriguing was an architecture firm that was experimenting with a 'walking' 3D printer. It could be programmed to 'print' a building, layer by layer. One of its 'jets' sprayed on stressed concrete solution for floors and walls and ceilings. Another jet carried a powder metal that as the walls were being built it sprayed in wiring. Similarly with plumbing. Pretty cool.

So a few things that the printers are being used for now:

a model of Manhatten, made from 3D google maps



A bakery 3D printer



A replacement jaw made from CAT scans



The biggest use is currently found in the auto industry building prototype parts. But from a novelty just a few years ago to having even home based printers available now for $1,700.00, this really is having a profound change on our world. Any material that can be made into a powder, a liquid, a gel, or an aerosol can be loaded into a 3D printer.

Then there's this. The 'thingiverse'. Its an online public domain library of 3D printable object for all to use.

http://www.thingiverse.com/tool:36

[Mrleft8]

It was an interesting segment.... There was one on the same subject on Sci-fri a few months ago..... That 3D map of Manhatten is amazing.... It almost looks like Manhattan.....

[McMike]

I hang out with a group of folks who have built a 3D printer and are currently calibrating it. While I am not directly involved in the build, I have been watching and giving support to the two fellows who are. Make no mistake, this is the wave of the future for manufacturing and there is a lot of money to be made to those who can harness it and market it first and properly.

The first task for our new printer will be to produce all the plastic parts for a new printer. Self replication is the ultimate goal; there are methods that can produce metal parts, while we don't yet possess the means to reproduce those methods, they are out there.


Google, "additive manufacturing"

[McMike]

[wardd]

the military especially the navy is interested in it for printing spares

[Hwyl]

I used one to make the molds for the sheaves on my pulley system project.

[McMike]

[Paul Pless]

I used one to make the molds for the sheaves on my pulley system project.

Cool. I'd be happy with a flourless chocolate tart myself.

[ljb5]

I've got one at work that we use all the time for prototyping small parts and fixtures.

It's really fun to watch and cool technology, but it is slow, expensive and limited.

If all you want is stuff made out of cheap, friable plastic, (or a very limited selection of materials), it does great work.

Once you want to go into production, however, it's not economical.

The physical properties of materials depend a whole lot on how they are processed. Drawing, rolling, stress hardening, heat treating, doping, diffusing, etc make materials what they are. You cannot just make everything out of isotropic sintered powder and get the same results.

Also, from my perspective, the whole field is kinda coarse and sloppy. I'm more used to 3D printing on the atomic level:



This marcoscopic stuff looks to me like Picasso painting with a paint roller.

[ljb5]

Also, no one ever talks about the expense and difficulty of prepping the raw material prior to printing. You think ink jet printer cartridges are expensive? Whoa!

Some materials, like copper for example, are super easy to work with in the bulk form (drawing into wires or rolling into sheets, for example. Alternatively, you can just dissolve them in an acid and let the ions do the work. Electro plating and electroless plating are great ways of using a liquid bath to put material exactly where you want it, without all the hassle of 3D robot motors.

In order to do the same work with a 3D printer, you'd first have to take your bulk raw copper and process it extensively to get mono-disperse nanoparticles that don't clump but can be fused. That's quite a challenge. I know one company spent about $11 million on a conductive ink printer that was never used in production because the silver nano-particle ink cost something like $45,000 per liter which came out to about 80% of the total sales price of the product... and that was just one of 30 process steps. Basically, it would have been like taping a $10 bill to every product they made and sell them for $8 bucks.

[Paul Pless]

ljb5, you make very good points. I think at this point in time its pretty clear the process is best utilized for prototyping and mold making and such. Katherine has worked with them a bit in automotive R&D. She often makes a mold for a prototype production run of a part that will stamp or cast or press a couple hundred parts before the quality becomes to poor, to see if the produced parts are gonna fit correctly. If they do fit, they'll make a mold out of another material using a different process (often EDM) that might make 250,000 parts before it wears out.

[wardd]

in the future we may have 3d printers at home which will greatly change the face of manufacturing and retail

[McMike]

in the future we may have 3d printers at home which will greatly change the face of manufacturing and retail

The future might be in six months for me. I can build one for under $800

[Dan McCosh]

The concept is widely used in prototyping. The range of materials is actually quite ride, ranging from UV-catalyzed polymers, to laser-sintered powdered metals. The technology currently is quite slow by production standards, but quite fast compared to alternative prototyping processes.

[Mad Scientist]

One of the early researchers in this was married to an RN. She described an invention - a clamp that could be adjusted to contol IV flow - and he printed a prototype in just a few minutes.

As mentioned, this will be huge when the cost comes down.

Tom

[Dan McCosh]

The latest cool new machine I've seen is a water-jet cutter. Carves steel with a glorified squirt gun.'

[ljb5]

I think at this point in time its pretty clear the process is best utilized for prototyping and mold making and such. Katherine has worked with them a bit in automotive R&D. She often makes a mold for a prototype production run of a part that will stamp or cast or press a couple hundred parts before the quality becomes to poor, to see if the produced parts are gonna fit correctly. If they do fit, they'll make a mold out of another material using a different process (often EDM) that might make 250,000 parts before it wears out.

I actually went through three iterations of a tool design this week. I do the design in SolidWorks (3D CAD) and then send it direct to the 3D printer (SLA). We finalized the design on Friday and get the stainless steel tools next week.

It works pretty well for the very simple stuff. But here's the thing: prototyping in plastic is not the same as making tools in metal.

The general shape is the same, but the surface finish is not. SLA gives you a rough, pixelated surface. When I get the prototypes back, I have to sand down the sides where I want the parts of the tool to slide past each other. That changes the dimension by half a mil, which was not intended.

The mass is completely different, which can through off your center of gravity (if you have multiple materials in a toolset.) The coefficient of thermal expansion is not the same. Heat conduction is not the same. Young's modulus, bulk modulus, abrasion resistance, coefficient of friction... all completely different.

And don't even bother with electrical or magnetic properties: dielectric constant, coercivity, magnetostriction. These are important.

Even if you use one of the fancy new systems that uses sintered stainless steel instead of crappy plastic, it's still not the same as milling it out of a block of metal.

Then, after you got the prototype, how do you test it? At some point, you gotta stick it in an Instrom or attach strain gauges to it, put it in a shock/vibration machine, subject it to hydrostatic pressure or reheological testing or something. Even if you could trust your results (which you can't because the materials are all different), that's a huge expense.

But here's the kicker: modern 3D CAD programs like Solidworks and Pro-E are capable (or very nearly capable) of calculating all these properties in a matter of seconds. They can do flow rate and turbulence in pipes and manifolds, show stress and strain distribution in a solid body, calculate the movement of complex linkages, fracture and buckling, etc. And if you change materials in mid process (like from Delrin to PTFE), or decided to harden your steel to Rockwell 56 instead of 40, they can recalculate all the results in a second.

So, on the one hand, we're getting super excited about 3D printing which can produce crappy prototypes in an hour or two that don't give you realistic results.... but on the other hand, we're getting very close to the point where you can get the same (or better) results out of a computer in a matter of seconds. (And then, you can program it to recalculate the dimensions of the part to optimize your design. I.e., if you want a rod to be as light as possible, but not too thin, the computer can figure that for you.)

Neither system is perfect yet, so we still have to do multiple iterations of design and prototype before releasing to production... and even then, we do multiple iterations of "finalized" design. But we're in a race to see which technology will advance the fastest. The way it looks to me, there's no competition. In silico prototyping will win out because it can calculate so many more properties and give more realistic results. Even more convincing: every product has to go through a 3D CAD program before it can be made into a 3D print, so you've pretty much already done the prototype in the computer before you've even started the SLA.

So far as I've seen, the only thing SLA is really good for is marketing. Buyers have a strong bias for stuff they can touch and hold, even if it's just a pale imitation of what they're really going to get.

[McMike]

Hmmm, well, we have a working rep rap that is made from printed parts that seem to be doing all the work they were intended to do. The machine is not perfect, the software is open source and persnickety. Even so, I'm convinced there is more value than novelty in this. I'm also convinced there is a lot of work yet to be done.


What I don't understand is your relative dismissal of the process, while I do find truth in what you've said, I don't find your conclusion is reflective of the technologies' current potential nevermind it's potential in the very near future.


Edited to add:

I fully understand that the process is not a fit for the type of prototyping that you do but a printed titanium jaw installed in a real live human person is quite a value and creates a relevancy For the process where you've found none.

[Y Bar Ranch]

So far as I've seen, the only thing SLA is really good for is marketing. Buyers have a strong bias for stuff they can touch and hold, even if it's just a pale imitation of what they're really going to get.

Anytime you need to actually interact with the artifact, prototyping is useful. So evaluating a new steering wheel for feel is something you can't do in the computer (yet). Also, evaluating ease of assembly of multiple components. Anything else that depends on outer geometry, like propellers or hydro shapes in general.

I don't know anyone who uses rapid prototyping to evaluate the physics of the part itself, since as you point out it depends so much on the material..

Researchers at Iowa state have developed the ability to use traditional mills as rapid proto typing machines in a subtractive process. Some restrictions on geometry, but you generate nc code and get to cutting in minutes. Google "Cnc-rp". You can make complex shapes out of metal parts. They have used it to make replacement titanium body parts. Not 3d printing, though.

[Keith Wilson]

Ljb makes some good points, particularly about the analysis capability of ordinary modeling programs like Pro-E or SolidWorks. (I use SolidWorks all the time BTW.) I think 3D printing will be useful in the future for one-off parts, and possibly things with complex shapes like that jaw prosthesis that are difficult to make by conventional methods. The major cost advantage is that high-class machining takes expensive machines and a highly skilled person. A 3-D printer doesn't.

I don't see it being used in ordinary series production for a long time, if ever. Look at standard printing; one-off documents are printed by ink-jet or laser. Mass-production books are not, and never will be.

[Paul Pless]

I actually went through three iterations of a tool design this week. I do the design in SolidWorks (3D CAD) and then send it direct to the 3D printer (SLA). We finalized the design on Friday and get the stainless steel tools next week.

It works pretty well for the very simple stuff. But here's the thing: prototyping in plastic is not the same as making tools in metal.

The general shape is the same, but the surface finish is not. SLA gives you a rough, pixelated surface. When I get the prototypes back, I have to sand down the sides where I want the parts of the tool to slide past each other. That changes the dimension by half a mil, which was not intended.

The mass is completely different, which can through off your center of gravity (if you have multiple materials in a toolset.) The coefficient of thermal expansion is not the same. Heat conduction is not the same. Young's modulus, bulk modulus, abrasion resistance, coefficient of friction... all completely different.

And don't even bother with electrical or magnetic properties: dielectric constant, coercivity, magnetostriction. These are important.

Even if you use one of the fancy new systems that uses sintered stainless steel instead of crappy plastic, it's still not the same as milling it out of a block of metal.

Then, after you got the prototype, how do you test it? At some point, you gotta stick it in an Instrom or attach strain gauges to it, put it in a shock/vibration machine, subject it to hydrostatic pressure or reheological testing or something. Even if you could trust your results (which you can't because the materials are all different), that's a huge expense.

But here's the kicker: modern 3D CAD programs like Solidworks and Pro-E are capable (or very nearly capable) of calculating all these properties in a matter of seconds. They can do flow rate and turbulence in pipes and manifolds, show stress and strain distribution in a solid body, calculate the movement of complex linkages, fracture and buckling, etc. And if you change materials in mid process (like from Delrin to PTFE), or decided to harden your steel to Rockwell 56 instead of 40, they can recalculate all the results in a second.

So, on the one hand, we're getting super excited about 3D printing which can produce crappy prototypes in an hour or two that don't give you realistic results.... but on the other hand, we're getting very close to the point where you can get the same (or better) results out of a computer in a matter of seconds. (And then, you can program it to recalculate the dimensions of the part to optimize your design. I.e., if you want a rod to be as light as possible, but not too thin, the computer can figure that for you.)

Neither system is perfect yet, so we still have to do multiple iterations of design and prototype before releasing to production... and even then, we do multiple iterations of "finalized" design. But we're in a race to see which technology will advance the fastest. The way it looks to me, there's no competition. In silico prototyping will win out because it can calculate so many more properties and give more realistic results. Even more convincing: every product has to go through a 3D CAD program before it can be made into a 3D print, so you've pretty much already done the prototype in the computer before you've even started the SLA.

So far as I've seen, the only thing SLA is really good for is marketing. Buyers have a strong bias for stuff they can touch and hold, even if it's just a pale imitation of what they're really going to get.

You miss my point. They will make a mold on the 3D printer out of whatever that material is. Then they will put that mold on the actual machine on the production line that makes lets just say the actual seat belt bracket. Now this 3D Printer mold will only be good for making a few dozen parts before it wears out of spec but it allows the engineer to make sure of the design in a production setting before they have the mold made of more permanent material that will make several hundred thousand parts before wearing beyond spec; but will also cost several hundred times what the 3D printer mold cost.

[johnw]

So, you can make stuff with it, but you're limited as to materials. That's fine, people will learn what applications it's suited to and use if for that. Prototyping parts that can be better explored on the computer doesn't sound like one of them, but I'm sure there will be plenty of applications.

[Mrleft8]

My thoughts on cost/benefit, and several other issues like crude, Vs. intricate, etc. is that in 1979 no one really thought that a laser jet printer would be a viable office product for small business.... Way too big, expensive, complex...... And now, they're old school machines that have been replaced with faster smaller machines that do more for less......
Perhaps these proto-types will develop into the dinosaurs of the next generation of molecular construction techniques, where one molecule will automatically build onto it's self to recreate it's origin..... And then like all good Darwinian creatures, evolve to the next level on it's own.....
"Good morning Dave..... You were out late last night, Dave..... That's not nice...."

[Dan McCosh]

GM actually has a small museum that traces the development of these processes. Both the materials and the techniques have changed dramatically, with the only common theme the ability to translate a CAD design into a 3D object. They are inherently slower than most other manufacturing process, as they all build a shape in layers or bits of material, rather than stamping, molding, etc. Still quite useful in the design process, and they can fabricate some shapes impossible with more conventional systems.

[wardd]

3d printing is in it's infancy, it will improve and other materials will be added

how many home gadgets does the average household have that could be printed with next generation printers?

some of us here are approaching this from our own particular expertise and failing to see the broader possibilities

i see 3d printing as another step in automation that has social consequences that have not been discussed here

[Dan McCosh]

Quite true. While automation has been around for about 100 years, 3d printing is only about 30 years old.

[wardd]

i remember when screw thread machine and the hydrotel were considered automation

[Dan McCosh]

One of the early applications of automation--machining operations that loaded and completed operations without a human operator--was in WW I. Electronic controls emerged in the late 1950s. Robotics in the 1960s, and so on.

[wardd]

the loom, and the english had automation for making block for rigging war ships

[Dan McCosh]

The idea that "printing" an object on demand is the future of manufacturing does have some interesting possibilities. It's a parallel to the idea of printing-on-demand, which was posed as the future of publishing from roughly the late 1960s until recently, when it pretty much was abandoned. It's last vestige is in marine stores, where charts are routinely printed on demand. Modern manufacturing produces many things at small margins above the cost of materials. Creating an object at the point of use is not only slow, but inherently expensive, due to the heavy capital cost per unit and, as mentioned, the high cost of prepped materials. Less ambitious programs, such as flexible, low-volume, low-cost manufacturing plants also have been proposed, and some of these ideas are gaining traction. Still, I doubt these "printing" technologies will have a big impact on how things are manufactured for sale. If you want to start making something at the point of consumption, I'd try a garden in your backyard first.

[johnw]

The idea that "printing" an object on demand is the future of manufacturing does have some interesting possibilities. It's a parallel to the idea of printing-on-demand, which was posed as the future of publishing from roughly the late 1960s until recently, when it pretty much was abandoned. It's last vestige is in marine stores, where charts are routinely printed on demand. Modern manufacturing produces many things at small margins above the cost of materials. Creating an object at the point of use is not only slow, but inherently expensive, due to the heavy capital cost per unit and, as mentioned, the high cost of prepped materials. Less ambitious programs, such as flexible, low-volume, low-cost manufacturing plants also have been proposed, and some of these ideas are gaining traction. Still, I doubt these "printing" technologies will have a big impact on how things are manufactured for sale. If you want to start making something at the point of consumption, I'd try a garden in your backyard first.

I can go to Seattle and get a book printed on demand at the University Bookstore in about 20 minutes. I sort of doubt it's making them any money, though.

http://dailyuw.com/news/2010/feb/04/...day-gutenberg/

[John Meachen]

The latest cool new machine I've seen is a water-jet cutter. Carves steel with a glorified squirt gun.'

Quite some squirt-the last time I saw a new water-jet cutter it operated at 60,000 psi and the work was done by garnet dust.There was a pure water machine close to reaching the market but it operated at 90,000 psi.The nozzles needed replacing fairly frequently in either case.

Rapid prototyping has come a long way from the stereolithography machines of a few years ago and maybe we should be glad they existed as they bequeathed us the .stl file family.The most impressive thing I have seen from a rapid prototyping machine was a model of a truck differential made by fdm and the detail was good enough that turning one driveshaft flange while holding the propshaft flange,resulted in the gears driving the free driveshaft flange backwards as the internal parts all moved.

[Canoez]

One of the neatest RP technologies I saw - better than SLA or some of the other fused material processes that use ABS or fairly crumbly rubber-like materials was a process called Direct Laser Sintering. A metal powder was was graded by particulate size gets loaded into the machine. The laser melts the metal to a solid form, not a porous form typical of sintering processes. The resolution was pretty good - around +/- 0.0005", IIRC. The parts are actually as strong as similarly processed material of the same alloy as is being sintered.

[AnalogKid]

A story from the BBC website on Future Health...

"[Our lab uses] a desktop inkjet printer, but instead of using ink, we’re using cells." — Anthony Atala


Surgeon Anthony Atala demonstrates an early-stage experiment that could someday solve the organ-donor problem: a 3D printer that uses living cells to output a transplantable kidney. Using similar technology, Dr. Atala's young patient Luke Massella received an engineered bladder 10 years ago; we meet him onstage. Talk recorded 3 March 2011.

[coelacanth2]

I no longer do much by way of facial prosthetics in my practice - I'm a decent but sloooow sculptor and sufficiently color blind that it takes me forever to match skin tones. The medical artist I'm working with is using the services of a local machine shop in Baltimore. They scan the patients face, flip the unaffected side over the defect area and morph it to fit and use a 3D printer to make a wax pattern. The artist does a final fit on the patient invests it and processes it in silicone. It still has to be hand painted but the results are stunning. Make the pattern in wax or an easily ironed out plastic and have a local foundry or partial denture lab cast it. The denture lab can cast it in a chrome cobalt alloy which is immensely strong and non corrosive.

[Norman Bernstein]

Hate to rain on the parade, but when we were going to prototype the pastic case for our product, it was actually a lot cheaper to simply have it CNC machined out of polycarbonate, in China, than to have it built with SLA or any other 3D printing process... and the result was better, since 3D printing materials are nowhere near as strong and stiff as polycarbonate.

I view 3D printing as complimentary, not revolutionary.... until 3D printing reaches the state of art where it can 1) print with durable materials, and 2) is fast enough to supercede CNC machining as a means of making limited production runs, it really won't have quite as big an impact as some might think.

[McMike]

Hate to rain on the parade, but when we were going to prototype the pastic case for our product, it was actually a lot cheaper to simply have it CNC machined out of polycarbonate, in China, than to have it built with SLA or any other 3D printing process... and the result was better, since 3D printing materials are nowhere near as strong and stiff as polycarbonate.

I view 3D printing as complimentary, not revolutionary.... until 3D printing reaches the state of art where it can 1) print with durable materials, and 2) is fast enough to supercede CNC machining as a means of making limited production runs, it really won't have quite as big an impact as some might think.

Don't forget Norm, 3D printing/additive manufacturing does not require several steps in the refinement process and billet production that reductive manufacturing requires. There has to be a reckoning between the time saved on one side vs. time added on the other . . . kind of like taxes. While I'm certain the scale has not tipped towards AM as of yet in terms of efficiency, I am convinced, within 5-10 years, it will for certain applications. I think the improvements in nano-tech in regard to materials science is going to lead to some paradigm shifting materials, potentially ones that will move AM into a very viable set of methods.

[Canoez]

Hate to rain on the parade, but when we were going to prototype the pastic case for our product, it was actually a lot cheaper to simply have it CNC machined out of polycarbonate, in China, than to have it built with SLA or any other 3D printing process... and the result was better, since 3D printing materials are nowhere near as strong and stiff as polycarbonate.

I view 3D printing as complimentary, not revolutionary.... until 3D printing reaches the state of art where it can 1) print with durable materials, and 2) is fast enough to supercede CNC machining as a means of making limited production runs, it really won't have quite as big an impact as some might think.

FYI - You can get rapid prototyping done in Polycarbonate, Norm. (http://www.xpress3d.com/Materials.aspx - among others) I have to agree, that cost-wise, it's getting more competitive, but still isn't quite there. We had a clamp prototype fabbed this spring and it probably would have been competitive to have had the parts machined from aluminum locally.

[wardd]

everybody is missing a biggie

it's the home printer that will bring the big change in the way many products are distributed and purchased

[McMike]

everybody is missing a biggie

it's the home printer that will bring the big change in the way many products are distributed and purchased

I'm not missing it, it's not ready for prime time yet. Soon, but not yet.

[wardd]

I'm not missing it, it's not ready for prime time yet. Soon, but not yet.

that's what i've been saying

i bet on with in a decade more like 5 years or so

then the plastic kitchen utensils at walmart will disappear