MakerBot Industries

Duplicating Disc Detainer Keys by nrp

Thingiverse user nrp has been working on using his 3D RepRap printer in some pretty amazing ways.  He’s already put his 3D printer to use along with a Kinect to print by use of hand gestures.  Since then he’s been working on duplicating house keys and the more secure disc detainer keys pictured above.  Nrp’s website, and the comments that go along with his detailed posts, provide a wealth of information about his project along with lots of interesting links about computer enhanced key generation.

This project and the way nrp uses his printer remind me of the very cool Nickel for Scale project by Amy Hurst and MakerBot’s own Marty McGuire.  How cool would it be to never have to go get keys made again?  I don’t think it’s too much to dream that one day you might be able to put a key down next to a nickel, take a picture or short video, and have your MakerBot crunch out a few duplicates.

Duplicating House Keys by nrp

Full writeup on my blog at: eclecti.cc/hardware/physical-keygen-duplicating-house-keys-on-a-3d-printer It occurred to me recently that I had printed almost nothing actually useful on my RepRap 3D printer, aside from parts to improve on or build more RepRaps. I am rectifying that with this project. The goal here is to generate working house keys by inputing the key code of the lock into a parametric OpenSCAD model. Instead of having to explain to my landlord how I ended up with a wedge of plastic jammed in my front door, I ordered a box of (well) used locks and latches from eBay to experiment on. Luckily, the lot includes both Kwikset KW1 and Schlage SC1 locks, which are the two most commonly found in the US. I created an SC1 model to start with, but I’ll probably make a KW1 soon. EDIT: I uploaded a KW1 model as well. Designing the key model was actually pretty straightforward. I measured a key with a ruler and calipers and created an approximate model of it that is reasonably easy to print. I then got pin depth specifications and parametrically differenced them out of the model. To generate new keys, you can just edit the last line of the file and enter in the key code for your key. If the code isn’t written on the key, you can measure the height of each bit and compare to the numbers in the Root Depth column on the aforementioned pin depth site. Perhaps more nefariously, you could implement something like SNEAKEY to generate key codes without physically measuring the key.

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Duplicating Disc Detainer Keys by nrp

Writeup containing actual links at eclecti.cc/hardware/physical-keygen-now-for-disc-detainer-locks The Physical Keygen post got some interesting reactions, but there was a common claim among many of them that it was just a gimmick because there are more practical ways of getting past basic Schlage and Kwikset pin tumbler locks. I agree with that, and I’ll also admit that a fair number of my projects are gimmicks, or as a stretch, art. Schuyler Towne of Open Locksport saw past the gimmick (or art) and into the possibility of printing keys for more interesting locks. He stopped by recently with a collection of said locks, and over the period of a few hours we found that keys for disc detainer locks were printable and created a nearly working ABUS Plus key. He left me a cutaway lock, and over the next week, I refined the model to the point of working straight off of the printer. Despite being a higher security lock than the SC1 or KW1 pin tumblers I was working with before, the key is much easier to print accurately. The OpenSCAD model is linked below, and like the last files, you simply edit the last line to match the code for your key. The ABUS Plus and other disc detainer locks are much more common in Europe than the US, but we do have a pretty ubiquitous example around here. After the Bic Pen debacle in 2004, Kryptonite switched their bicycle U-locks from tubular to disc detainer. I designed a model off of the key from the Kryptonite Evolution I have, but as of yet, I have not successfully opened the lock with it. The key is smaller and thinner than the ABUS Plus, causing it to flex too much to effectively turn the last few discs. I’ve posted the file anyway, in case someone has stronger plastic or an idea to strengthen the model. EDIT: The Kryptonite key works. I tightened my X and Y belts and printed it a bit slower. Apparently some of the blobbing on the corners before was catching on disks.

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Thingiverse citizen nrp uploaded a Python script that enables a Kinect to track a hand in the air and feed the corresponding Gcode to a 3D printer – a process he calls “gestural 3D printing.”  From the video above you can see how the monitor provides visual feedback for the user while his RepRap in the background mimics the user’s movement.

Gestural 3D Printing by nrp

Really, the best description is the video:youtube.com/watch?v=BRJY927raTo Also on my website:eclecti.cc/computervision/gestural-printing-jumping-the-shark-on-kinect-hacks We’ve seen a seemingly endless array of amazing Kinect hacks over the last few months, from superhero generators to obstacle avoiding quadcopters. However, it was only a matter of time before someone came up with a hack so inane and irrelevant that it would bring shame to the entire hobby. That time is now, and that someone is me. I bring to you, gestural 3D printing! Using the Kinect to track your hand, you can draw one layer at a time, with the printer following your every move. Pushing forward extrudes plastic, while pulling your hand back will start a new layer. Who needs difficult and confusing CAD software when you can just directly draw the object you want to print?

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M8 CableClippy by elk

Tired of zip tying things, cutting those ties, and the re-zip tying them?  How about trying to reuse those nearly useless grocery store twist ties to organize cables?

If you’ve got a 3D printer like elk’s RepRap, why not just print up some of his CableClippies?  Simple, quick to print, reuseable, and even cheaper than any alternative – they’re exactly the sort of thing at which  DIY 3D printer excels.

M8 CableClippy by elk

This is a clip to fit the M8 studding / rods of a reprap mendel machine and hold any wires / cables down to the rod. It can be used instead of zip ties (I had to cut many zip ties again during my mendel build). The CableClippy can be re-opened with ease and helps to keep your cable chaos neatly arranged :)

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Nophead's plate of Huxley RepRap parts

A little while ago I asked what would you do with double the printing capacity of a 3D printer.

Here’s a better question, what would you do with more than a 100 times the printing capacity?  Nophead, author of the excellent HydraRaptor blog, recently announced he printed 101 full sets of RepRap Mendel plastic parts over the course of the last year.  He’s essentially also answered an interesting practical question – how fast can a RepRap 3D printer replicate plastic parts under human supervision? ¹ While he used his CNC mill with a printer head, HydraRaptor, this hardly diminishes the accomplishment.  Printing that many sets of parts takes a lot of dedication and time.

Now that we’ve thought about what is possible with two 3D printers, Nophead’s achievement raises so many new and wonderful questions:

• What would you do with 102 printers? ²
• What would you do with 1 printer and 101 friends who also had printers? ³
• What would happen to 101 brilliant start-ups if they were each given a printer, a computer, and a pile of plastic?
• What would happen to 101 brilliant and disadvantaged students if they were each given a printer, a computer, and a large pile of plastic?
• What would happen to 101 poor villages across the globe that suddenly had access to a printer, a computer, and a large pile of plastic?⁴

1. He states that these 101 sets were printed over about 4800 hours, so perhaps 47.5 hours per set? [↩]
2. The original one plus the 101 children. [↩]
3. Don’t have 101 friends?  Pssh.  I’ve seen your Facebook profile. [↩]
4. I think the transformation could be on par with something like the Universal Sheller from the Full Belly Project [↩]

Printed birdfeeder by araspitfire

I like this birdfeeder design by araspitfire for repurposing, recycling, and of course, for using 3D printed parts.  It looks too large for printing on a MakerBot Cupcake or Thing-O-Matic, but from the way it is displayed, I think it’s a pretty safe bet the birdfeeder outer ring can be printed on a RepRap Mendel.

I’ve got some family who live in Michigan.  One year for someone’s birthday we bought a hummingbird feeder online and had it shipped to us in the Bay Area, so we could gift wrap it and send it to him.  Now, take a moment and ask yourself – what would be funnier than a hummingbird feeder with a carbon footprint going all the way back to China?

Answer: A hummingbird feeder made in Michigan, shipped to California, only to be shipped back to Michigan.

Imagine if a loved one had their own 3D printer, you could just e-mail them a digital file of a lovely design that you thought they would enjoy – rather than shipping something from their home state/country, wrapping it, and shipping it back to them.

Shooting for 300

Josef Průša is giving a talk at the TedX event in Prague on November 20th.  You may recognize his name from his contributions to the development of the next generation RepRap printer, the Mendel.  Josef has been working to simplify the parts and reduce the print time for the parts necessary to create a RepRap printer.  In order to demonstrate the possibilities of DIY 3D printing, Josef is looking to give away 300 printed whistles at this event.

As of yesterday, Josef still has 250 more whistles to go.  Can you help Josef spread the word by sending him some whistles to give away?

At the “IF … Innovation Festival Kortrijk” Dries Verbruggen demonstrated his virtual pottery wheel¹ and what appears to be a RepRap Darwin² with a clay extruder to create physical models of virtually designed pots.  This video is just so brilliant!

Designguide.tv interview from Unfold on Vimeo.

Besides the super awesome Minority Report style virtual display design interface which puts Sketchup to shame, I love that the pottery wheel is basically a perfect analogy for the design “limitations” of a MakerBot.  (I say limitations because it turns out the “45 degree rule” is more of what you call “guidelines”)³

Sometimes when people send me design files to print they contain overhangs that are totally unprintable without a support structures.  For someone who hasn’t actually used a MakerBot-style 3D printer it takes a few tries to really “get” how it forms models.

Verbruggen’s virtual pottery wheel appears to strictly apply to the “virtual clay” whatever impression you make upon it – allowing you to make pots that aren’t printable.⁴  However, there’s no reason why the virtual display couldn’t make use of a simple physics engine to have unsupported clay structures fall – just as real clay would on a real pottery wheel.  I have a feeling interacting with the object as it is being formed and receiving immediate feedback if there’s a structural defect is the kind of thing people would just “get” intuitively.

1. It appears to use a green laser as a 3D scanner to detect the position of your hand and apply an equivalent force on the virtual clay. [↩]
2. The Godfather of the MakerBot [↩]
3. Thank you Captain Barbosa! [↩]
4. You can see several such models projected on the wall behind him. [↩]

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The RepRap project announced the RepRap Version III named “Huxley” a little over a month ago. ¹ It’s based on the mini-Mendel by Ed Sells.  Interestingly, if you compare the last few iterations of the RepRap, from the Darwin, Mendel, and mini-Mendel – you’ll notice the build volume is shrinking.  As these RepRap designs have evolved, the replication time has gone down, non-printed parts have been decreased, but the usable build area keeps decreasing. ²  I suppose if self-replication is the highest goal, the machine and build volume should continue to miniaturize. 

This raises an interesting question about the optimal size of a 3D printer.  How much build volume do you want or need?  I tend to use an 80-20 rule-of-thumb for such things.  I’m usually happy with a solution that can do everything I need 80% of the time. ³  I suppose if you refused to compromise on build area, you’d have to go with a commercial printer or design your own super-mega-9000 giant printer.

I normally print out small parts, replacement parts, MakerBot parts, or toys – so, I’ve never felt constrained by my Cupcake’s build volume.  And, I’ve felt even less constrained as new printable upgrades are developed that allow you to increase your build area.  I can’t say for sure, but I suspect build volume isn’t that big a deal for most other people – otherwise we’d see more printable volume-increasing upgrades and more attempts at the MakerBot longest print Hall of Fame record.

1. Photo courtesy of didelco10 [↩]
2. Amusingly, it’s likely Webca’s printable Cupcake, which takes a really long time, only made MakerBots even more popular.  Go fig. [↩]
3. That’s one of the reasons I’ve been using a netbook for the last two years.  Long battery life, low price, good portability, but no optical drive – which I never used that often anyhow. [↩]