Project : Atomic Sun

Progress and innovation let us build a world that departs increasingly from the environment for which we evolved. To resolve the mismatch between our genetic disposition and the world we build, we must either adapt our environment or adapt ourselves. Winters are pretty dark up here, some days I'm not sure the sun even rises. So, I built this lamp. Its on a timer, and functions to keep the circadian rhythm intact.

These are instructions for building a very bright lamp with 20 bulbs and a truncated icosahedral core. Development set me back about $120 total ( bulbs included ), but you should be able to build this for as little as $40 not including the light-bulbs or cost of plastic.

Edit : This was printed on a MakerBot Cupcake which costs $850 now. If you can't afford one, your local hackerspace may have one, but they are difficult to get working. Plastic costs 0.024/gram. $34 is a lower bound on the costs, excluding the printed parts and bulbs. My costs were higher because of waste. The sockets are the only part you can't scavenge or print. You could print those as well, if you figure out how to do the wiring. I would have used LED bulbs if I could have afforded them at the time.

Parts :

• 1 × pentagonal hook http://www.thingiverse.com/thing:6117 "p hook 3"
• 12 × basic pentagons http://www.thingiverse.com/thing:5961 "p" ( pentagon )
• 20 × hexagonal lamp brackets http://www.thingiverse.com/thing:6055
• 20 × lamp sockets Cooper Wiring 732-BOX Sign/Scoreboard Lampholder
• 20 × low wattage CFL bulbs, like these
• 1 × electrical plug SA440-BKCC10 15A black nonpolar plug or equivalent ( any plug will do )
• 16 feet of 12 to 16 gauge lamp cord
• 6 feet of rope or chain
• 2 × (optional) rope holder thing http://www.thingiverse.com/thing:6149

Materials:

• electrical tape
• super-glue ( I used Gorilla brand )

Tools:

• Pliers
• 3D printer
• razor knife
• wire cutters
• wire strippers
• Phillip's head screwdriver

Assembly:

First print out the indicated quantity of all printed parts.

More detailed assembly instructions for the lamp socket brackets can be found on the thingiverse page. Trim the bracket until the black socket rests flush inside. This is important, since we need the hexagonal cover plate to bond to both the bracket and the socket for a good fit.

The orientation of the socket within the bracket will matter later. The socket has a wide ridge. Align this ridge with a side of the bracket for 10 pieces. Align the ridge with a corner of the bracket for the other 10. Aligning randomly also works, as long as you don't align all sockets so that the wide parts face a side.

Print out 12 pentagonal pieces. All pieces have extra plastic to stabilize the hinge while printing. This can be removed easily with a razor knife.

Perform a test assembly with just the hexagonal pieces. Leave out the pentagons for now since they are hard to remove once assembled. Ensure that all light sockets fit properly and don't collide. You may have to experiment, rotating and swapping between pieces, to get everything to fit well. If all else fails you can tap apart one of the brackets and re-orient it.

Carefully unfold your test assembly into an as-linear-as-possible planar arrangement like below. The exact arrangement doesn't really matter, just so long as there isn't too much branching.

The lamp sockets clip onto 12 to 14 gauge electrical wire. The only 12 gauge wire I could find had too thick of insulation to work with these sockets. I used 16 gauge wire instead, which just barely works. Using scissors or a knife, separate one end of the lamp cord. Protect the ends with electrical tape. Starting at the far end, clamp the sockets to the cable in turn. The sockets are difficult to close, so I had to use pliers to get enough force.

Before you get excited and attach the plug to test everything, slide on the pentagonal hook piece over the cable. The top of the printed piece should be facing away from the assembly, toward the plug. I neglected to do this, and had to dis-assemble my plug to add this piece.

To assemble the plug, use needle-nose pliers to remove the orange stopper from the front of the plug. Remove the prongs. Thread the lamp cord through. Split and strip about 13mm from the end of each wire. Wrap the exposed wire around the bolts attached to the prongs, and tighten the bolts well. Replace the prongs and stopper.

Test each of your sockets. Turn everything over and plug in some lightbulbs. I did it the dangerous way by adding and removing bulbs ( I only had 2 at the time ) while the thing was plugged in. People that don't want to die should un-plug the setup while moving the bulbs. Better yet, order the bulbs with the rest of your parts and put them all in at once to test.

The next step is tricky. Unplug the setup and remove the bulbs. Turn over the setup. You are going to need to fold the pieces back into the polyhedral shape. The lamp cord is inflexible and resists folding, but bending each joint beforehand helps. Adding in the pentagons while folding provides more stability. As the polyhedron becomes more complete, it becomes more difficult to add pieces. If you're having trouble getting a hinge to mate, pry up slightly the side that is already in the polyhedron. The hinges come together more easily if pushed together from the side, rather than if pushed down from above.

When it was all done, the compressed cable overpowered the super-glue on a couple brackets, thankfully this mistake is easily fixed with more super-glue and some patience. You should end up with an object that looks more than a little bit like the detonation mechanism for an atomic bomb. The final assembly is very strong and the hinges will hold together without additional glue.

The last piece you'll insert is the one that contains the power cord and the rope or chain for hanging the lamp. I would attach rope or chain before you add this piece. Don't use polypropylene rope like I did, it doesn't hold knots. A chain would look nicer anyway.

Thats it. You're done. Hang the lamp somewhere, insert bulbs, and power up your own miniature sun.

Rapid Prototyping ≠ Digital Reproduction

BoingBoing has mentioned a new whitepaper outlining the copyright and patent complexities of at-home 3D printing. Copyright violation and 3D printing may not be as big of a potential issue as the paper makes out.

The current copyright controversy is driven by the fact that duplicating an information artifact costs much, much less than purchasing said artifact. However, this effect is not present in 3D printing. The base material costs money, and the range of possible materials is restricted. Therefore, mass manufacturing of parts should still be cheaper, more efficient, and in some cases produce better products, than at-home 3D printing. These parameters may change as the technology matures, but I doubt the Chinese plastic trinket market is in danger anytime soon. Rapid prototyping is far more a means of creation than it is a means of production.

Most plastic objects we encounter day-to-day have little value added beyond their actual physical manufacturing cost. As long as mass production remains more efficient for plastic parts, there should be enough of a gap between the cost of home printing and the cost of an industrially produced item to discourage piracy. I understand that this is oversimplified : there may be objects that have artificially enforced scarcity, by copyright and patents. However, I just can't remember running into such an object, built only out of plastic, in recent memory. Design patents are still an issue, but these do not limit functional reproduction, only aesthetic.

I'm obviously overlooking some things. For instance, a 3D printer that could operate on recycled materials just might undercut mass production. However, there is still an upper limit to how much thermoplastic you want piling up in your house. If you had to physically print out every article you wanted to pirate, your study would rapidly fill with articles and papers ( and indeed, many of our office are such masses of papers ). At some point you'd realize that the cost of all that toner might not really be worth it.

Of course, you might get a situation where people pirate objects, print them, use them for a time, and then recycle them back into feedstock. But, what would have been the fate of the same objects had they come from industrial production ? Overwhelmingly, they would be destined, like so much of the rest of the 20th century, for our landfills, garbage islands in the Pacific, and the stomachs of (dead) albatrosses. The only way rapid prototyping could become a sustained threat to manufacturing is for rapid prototyping to become both sustainable and a viable means of manufacturing, of which it is neither at this time.

I feel that there is some sort of intrinsic efficiency gain to mass production that will always discourage piracy of printable objects, but I would also love to be proved wrong in this assumption. If or when printing technology matures to this point, well ... heh ... they'll never be able to stop us anyway.

p.s. : but seriously, the paper is good and basically a completely accurate, way better analysis, than this post. so, head over there.

MakerBot : Caveat Emptor

I'd like to discuss my MakerBot. Before I start, I must declare that many people have had success with MakerBot, so this post should be taken only as the real-life facts from the experience of a quite possibly less than competent MakerBot operator. With that out of the way :

New owners of MakerBots may be surprised by the amount of additional time and money required to get full performance out of their MakerBot. While this kit is certainly easier than attempting a full blown rep-rap, it has surprise drawbacks which have left many customers disappointed.

The first thing odd you might notice is that the kind, linear assembly instructions trail off just around the time you think you might want to turn on your MakerBot. Don't panic, it is around this time that you should desperately start bothering the MakerBot google group, since if you proceed blindly you might destroy your bot. MakerBots as they currently ship have a number of design defects, which will require your time and money to correct before you can fully enjoy the printer.

1 : The Teflon™ (PTFE) component of the part that extrudes plastic is prone to melting "losing its structural properties and deforming to an extent that it no longer can serve its intended function". If you've calibrated your temperature sensor incorrectly, or done something odd in assembling the hot end of the extruder, you will quickly destroy your MakerBot by melting deforming this Teflon component. What you weren't told is that this part can be protected by being wrapped in a bit of copper pipe and or hose clamp, but the kit doesn't ship with these. If you destroy this part, you will want to upgrade to an equivalent compoent made of PEEK from MakerGear that is significantly more reliable. Indeed, many MakerBot owners wonder why MakerGear extruder parts are not shipping standard with the kit, since most owners quickly upgrade. I spent about $60 in upgrade parts before I even really got started. I don't actually need all that, but I got some spare pieces in case something else breaks.

2 : You may experience inexplicable behaviors of the printer. Some of these are problems with the engineering on the electronics. Essentially, the electronics are not as noise resistant as they need to be. By default, you will need to twist all cables and install R18 ( 180 ohm ) on the motherboard extruder controller. This resistor does not come with the kit. Many people have also had to install ferrite beads to filter out noise from the lines. These do not come with the kit.

3 : You may find that printing objects with a footprint larger than an inch is very very hard. Why is this ? when the MakerBot advertises a 4"x4"x6" working volume ? As the hot plastic cools, it deforms, and as it deforms, it pulls away from the printing platform. Only very small footprint objects can be printed with the default MakerBot. In order to use the full volume of MakerBot, you will need to purchase the heated build platform (HBP) for $50.

4 : The heated build platform kit is hard to build and incomplete. It requires surface mount soldering. Furthermore, the current electronics on MakerBot can not handle the 3-4 amp current the heater draws. You will need to purchase and wire in some sort of relay, solid state or otherwise. Relays don't come from the kit, but a board can be purchased from MakerBot for $15.

5 : Calibrating the software is really, really, hard, and some parts just can't be printed for reasons related more to software than hardware. There is no standard MakerBot calibration file for the 3D printer driver software, but people are working on it. It takes a while to understand this monster and I'm still not done calibrating it for my bot.

6 : The extruder filament feed is under-engineered and hard to make reliable in its present incarnation. MakerBot ships with the MK4 extruder design, but you can buy more functional part from MakerBot for $10, which may or may not solve your troubles, I haven't tried it.

7 : The threaded rods that ship with MakerBot are of sufficiently poor quality that you might find yourself spending days trying to get the Z axis mechanism to work properly. I finally figured out that if I rotated the rods so that they were all bent in the same way, the tension on the driving belt would be closer to constant and my MakerBot would actually work. However, there were many, many days of cursing and manual adjustment, before I arrived at this solution. You can buy new rods at some cost that will be of more correct tolerance. You can also print out parts of a kit ( but not the whole kit ) for correcting "wobble" in your Z axis.

so, to recap :

• replacing the PTFE barrel with PEEK : 13USD from MakerGear
• modular heater core and thermistor from MakerGear : 20USD from MakerGear
• upgrading to heated build platform (HBP) : 50USD
• relay patch for HBP kit : 10USD
• 180 ohm resistor for motherboard : 10¢ ... maybe
• extruder gear upgrade : 10USD
• ferrite beads : ? ( did not use )
• ACME Z rod upgrade : ? ( haven't done )

So, thats totaling at least 100USD in upgrades just to get the bot in decent shape ( not including tax and shipping ). Thats not including unexpected repairs, and all the time spent cursing and wondering what you did wrong.

I guess, now that I look at it, $100 isn't that much, but it is evidence that this product is still in the alpha stages of development and cuts several corners, making it failure prone or downright broken. I am confident that with more time spent engineering, and perhaps with a minor $100-$200 increase in the cost of the kit, to increase the quality of the parts, this could actually be workable.

As it stands, many operators have spent hundreds of hours and been plagued with incomprehensible problems, and have never gotten their bots to print a single thing. Other people have had enormous success. I think part of it is down to luck ( how bent are your particular Z axis rods ? ) and pre-existing skill.

So remember, if you buy one of these, it is not a kit for amateur, or even perhaps intermediate hobbyists. If you are a novice at the time you purchase the kit, you will rapidly be required to upgrade your mechanical, electrical, and computer science skill set. It will take some time, and some people still don't have their bots printing. Budget extra time and money. The design cuts corners that can make it hard to work with, and if you buy now you are paying for design refinement that will finally bring the product out of alpha stage. If you do succeed, enjoy printing your calibration cubes. Maybe in a few months you'll work your way up to this.

What I am disappointed about is MakerBot is shipping these kits as if they worked almost right out of the box. They really should be advertising their kits as "parts only, functional MakerBot may require additional parts and design changes". I think that their advertising has been very effective, with many interviews with diverse news outlets. But, I also think that their advertising borders on false or deceptive, and might take some less experienced individuals by surprise.

update : opinions on the MakerBot forum echo these. There is agreement that the kit takes a lot of time and some upgrading may be required, but that this is generally expected for a DIY kit ( I didn't know that ). The argument is that this is still a fair buy for people with lots of time and patience, and that if they start shipping a huge number of kits they might have to put up a notice to adjust expectations closer to reality.

update : After I thoroughly determined that the Z rod defect was beyond my ability to correct, I asked for two new rods from MakerBot. They are shipping the replacement parts at no cost. So, if something really doesn't seem right, and suggestions from the forum aren't helping, and your rational mind determines that the fault is in the part, MakerBot is willing to replace the defect.

update : MakerBot will soon be upgrading their extruder design to Mk5, which should eliminate some of these problems.

So, issues 1,6,7 should be resolved shortly. Issue 2 of electronic noise has been solved on my bot by simply twisting all communications and power wires, and installing the 180 ohm terminating resistor. Issues 3,4 are inherent to the use of ABS : it will warp if not kept warm during the build. I am told that PLA does not suffer from this. Furthermore, issues 3,4 aren't really issues if you're good at soldering and buy all the HBP parts with your kit. Issue 5 isn't going to go away anytime soon since it requires quite a bit of software development. As the kit becomes more standardized and the variance between bots is reduced, a standard calibration may become available.

So I can now update my recommendation for the MakerBot : Research ahead of time, budget a couple hundred extra dollars, budget extra time, be patient, expect to have to improvise hacks, communicate with the forums and if all else fails the MakerBot people themselves. Learn to enjoy the process of building and debugging. If you're technically competent enough, in the end you will probably get a working 3D printer for a very reasonable price, thats easier to assemble and debug than a RepRap.