My Blue Robot

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IMG_6739You’ll see more of this guy in a bit. 

I saw a basic 3-D printing exhibit at Dragon*Con several years ago, a basic machine that printed rudimentary items like key chains.  I’ve followed the development of the technology, now more formally called “additive manufacturing,” to see it being used to make prototypes for engineering, replacement parts for machinery, medical implants and even food.  It literally depends on the “ink” used and the capabilities of both the printing device and the person who programs the instructions.

 

My daughter had an opportunity to use one for a project, for which she chose the Millennium Falcon.  She used this as a mold to ultimately lost-wax cast bronze replicas.

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A visit seemed like a good opportunity to play along, and a friend suggested a pretty cool 3D printed watch, which you can see below assembled, the movement mechanism, and parts to be printed.

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Pretty interesting and… the printing capability of the printer doesn’t print to that fine of a size.  So, in keeping with my not-so-themed blog, a robot made sense.  But it’s not like you can just make something.  Someone has to have taken the time to programmed the design into the computer, and that person isn’t me.  Handily, many of these designs are posted publicly, such as at www.thingiverse.com.  Search there for robots, pick one, and… I kind of liked this one.

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There were certainly others of interest, but size = time and money.  This guy seemed to fit the bill.  So, we downloaded the instructions to a jump drive, zipped over to one of the greatest engineering universities in the world and, here it is, a Dimension BST 1200es.  Looks kind of badass. 

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In 2009, this 3-D printer sold for $18,900 (marked down from $26,900 previously).  You should note that BST stands for Breakaway Support Technology.  The company also offers a SST version at $32,900, which stands for Soluble Support Technology.  The difference is that the latter version features an automated support removal station that uses a soapy bath to wash away support structures – as opposed to breaking it away.  AS someone who didn’t have to pay for it, they should have bought the upgrade.  More on that later. 

So we plug the jump drive in and… well, not so fast.  That dusty relic to the right is a Dell, running Windows XP, so that the software which was at the time recommended for Windows XP/Vista, runs the printer.  Only, my daughter’s jump drive was too large to connect into the space provided.

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So, we use the ancient computer to download the design directly, which may as well have been using a fax-modem.  Not impressed.  Finally, progress begins as the software starts throwing up pictures of my to-be robot as follows:

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Note that wherever you see the grey, that is the famed “support structure.”  As the printer head prints each layer of the object, there are spaces where nothing is intended to be printed.  The structure provides support for layers printed on future passes above it, externally as you see here and in internal cavities as well. 

The robot took several hours to print, and the cabinet enclosure prevents watching ink dry.  So, we left and returned quite a bit later, we open the cabinet, and…

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There he is.  No, he’s not orange.  I was told in advance that it would be blue because the guy who runs the lab likes blue and therefore only buys blue thermoplastic.  The white, as you’ll probably guess, is the support structure.  So let’s take a closer peek at the hatchling.

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What is left is to remove all the white stuff, so bring out the X-Acto knife and free the robot!

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That looks like good progress, right?  Only, that took a LOT of work. Basically, each junk piece represents one manual removal action.   At this point, his eyes are impossible to clear out with the tools available, his neck is frozen, and he has one knee joint that actually works.  He’s suffered a slight scrape on his back side during handling, but otherwise he looks in good shape.  So, to not spend hours upon hours in a lab on a Saturday night, I’m thinking… I’ll take the rascal home and finish him there.  Here’s how that works out.

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Oops.  Sorry about the legs.  So, here’s the thing.  The robot is designed to have 11 axes of movement.  The head turns, the arms and elbows bend, as do the legs, knees and feet.  That means that joints are printed within the robot, but… that support structure material is in there as well.  It is not as densely printed as the robot parts, but it remains a very stiff substance with a fondness for staying where it is.  You might think that applying some pressure would free the joints, but that isn’t the case.  When we removed him from the printer, he was still warm, but even then the plastic was stiff, and my daughter, properly trained in such things, was warning “be careful or you’ll break the movement.”  As seen above, yep.  She’s right.  And I do not feel guilty about it, either.  He’s rather small, and it’s easy for whatever tool you have to slip away and stab, scratch or generally irritate the hand holding it.

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Not that I did it all by hand.  No, early on I put him in a vice and brought out the Dremel.  Seemed like a good idea, bringing better tools for the operation - fine tips to get into the tiny cracks, an irresistible force… that kind of thing.  Only, RPMs equal heat.  So I ended up shaving the robot more than the support structure.  In any case, aside from lost appendages, he’s suffering pretty mightily.  At this point, I don’t care.  Note the support structure at his neck – much of it’s removed and loosened, but his head still won’t turn.  His left arm moves via a post through a hole away and toward his body, his shoulders are still frozen in place, and the other arm… oops. 

Here’s the inside view of the arm – the support structure within the joint is visible, and it doesn’t just flake out.  Even that bit required a blade to pry it from the blue arm piece.

Similarly, his head is going to turn.  There’s no question about it.  After doing all I can do, I leverage his head via a box cutter blade, basically not caring as he’s already scarred and in pieces.  Voila. You can see all the support structure under his neck after I’ve offed his head, though it separated with a surprisingly clean break at the neck.

It’s really quite clever, actually, as his neck is a post that flares at the bottom edge of the body so that it remains in place… in less aggressive circumstances.  The lower neck is at the bottom right in the picture below, again with that damned support structure that doesn’t give way.  And, while you’re looking, you can also see the most difficult aspect, which was the legs.  The leg has an undersized “O” that fits around a solid pin within the leg cavity.  The only thing preventing movement is… the support structure, and his body doesn’t lend itself to arthroscopic surgery.  As robots go, this one has repeatedly said “I’m stronger than you.”  And he’s right.  Neither encouraging words nor punishment has worked. That support structure remains in his leg cavities.  I can’t get it out.

Meh.  “Honey, what glue do we have for plastic?”  So, here he is, keeping scarred eyes on things, a vanquished X-Acto blade his trophy.

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His head turns, his knees and ankles work perfectly, and his left elbow works.  He’s glued at the right shoulder, his right arm will fall off if bothered, and he’s permanently resigned to a seated position for the rest of his days.  In short, “state of the art” 2009 3-D printing technology is not going to be a disruptive force for Chinese toy makers.  If I had to do it all over again, I’d find a new and improved 3D printer which tends less toward rigid support structures (the reviews of the design indicate this is the route to go),  locate the more expensive SST version of the printer with the miracle “Calgon take it away” soap solution for removing support material, or, failing that, I might try to nuke the guy to see if a blast of heat might free some joints. 

In any case, it was an educational and (mostly) fun project, with a reasonable souvenir at the end.

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