Details: I've wondered for a while if it would be possible to control a Nerf gun with an NXT. After following the MakeMagazineblog'sarduino-basedattempt (that's not even all the links, but you get the idea), I was relatively well convinced that it was too complicated, since it might require dismantling the Nerf gun itself. Not so! Today's model solves this problem with a simple cam assembly. That's before we mention the gargantuan - and yet still motorized - base, or the way this can be controlled by either a remote or NXT (done through Power Functions motors - a person can use the Power Functions IR remote, or the NXT will use a third-party IR component to control them). The video and links above fill in a few more interesting details. No word yet, though, on how you can get it to load more ammo.
Details: Every once in a while, someone builds something that actually breaks new ground in the field of what can be done with LEGO parts. This machine is one of those revolutionary moments. For as long as we've had CAD programs that could be used to create virtual LEGO models, we've had problems with parts not being available. Sure, you can make do (especially if you're a robot that doesn't have those parts either), but it seems inevitable that you'll eventually come up with something that just cannot be modeled on the computer. Parts repositories for LDRAW are filled with elements created from primitive shapes by volunteers, so it's not all that surprising that difficult, more organic shapes that LEGO makes are often unaccounted for. That is, until now. This setup is capable of generating LDRAW parts from scratch, using nothing but an NXT kit, a small amount of other LEGO parts, a laser component, a webcam, and some software. While the process is not entirely automated, it's a huge step forward in making part creation for complex parts simpler, which in turn will allow the rest of us to design in LDRAW with a wider variety of parts.
Details: Today's obligatory "cool LEGO robot everyone is talking about on the internet" is this NXT-based Roomba replacement. Although a good deal of custom electronics were involved to make it happen, I believe this is the first NXT-based robot capable of connecting itself to a recharging station (if you're unaware: only the education edition NXT kits come with the rechargeable battery by default, but you can buy the battery and charger separately through Shop at Home). A top-mounted dFlex sensor determines when it is as far as it can safely go under furniture. The expected differential drive and touch sensors are there too - for once I can actually say that the robot is very well documented by it's builder, so if you are interested in this (or want to build your own), please follow the links above to learn more.
The video I've featured above is just of the recharging action. A video of the "swiffering" can be seen on the site listed above.
Details: It seems like just a few weeks ago that we were talking about an NXT robot that could print LDRAW designs. We've also seen an NXT-based warehouse for gathering parts, based on the LEGO company's own warehouse. Now, we see a bizarre combination of the two - a 5-NXT factory (staffed with minifigures to "drive" the various motorized parts) that gets parts out of a warehouse and then builds with them using designs generated from LEGO Digital Designer files. The choice of LDD instead of LDraw (like in the previous model-building 'bot) does limit things in a way, but any loss there is made up for by the ability to handle a large and easily changed set of parts. The warehouse contains 95 different types of bricks - over 1500 pieces total to build with. Most impressively, this entire thing was built and programmed in less than 5 months - it was only started in June of 2010. To see some work-in-progress and behind-the-scenes footage, look at the builder's other YouTube uploads.
Here's what the whole LEGOWORLD set-up of this factory looked like (click to "enbiggen"):
Details: As seen in Zwolle recently, there is a new LEGO Mindstorms NXT-based version of Wall-E. This version tries to be strictly purist and true to the NXT system - not only does this not use any third-party robotics components, but this doesn't even use Power Functions motors (unlike the first great Wall-E we covered)! 8 NXT motors and 3 NXT programmable bricks were crammed in here to get this realistic and surprisingly expressive range of motion. While it doesn't transform, it seems to have every other Wall-E behavior down. Color sensors were even used to allow his eyes to light up in different colors. Don't miss the second link above, which has some photos of the internal mechanisms.
Details: In this video, this giant rover base is being run by remote control. At LEGOWORLD in Zwolle right now, it's operating autonomously, controlled by 9 NXT programmable bricks. Although the video and links above don't show the full version, they're impressive enough already and give you a sense of the sheer size of this 'bot. There's a close-up of the treads that shows that they're actually made out of hundreds (or more likely, thousands) of 3-stud long Technic beams. Another video from the event shows the completed robot driving around taking pictures from inside the crowd.
I'm guessing that we'll be seeing many more photos of this (and taken by this) model after the event is over...which I'll be rounding up here as I see them.
Details: The day has finally come. A LEGO robot is now capable of assembling a variety of LEGO models on its own, working off of LDRAW instructions generated in MLCAD. Would you like a robot like this? You can download instructions and programs for it in a number of formats, including MLCAD. That MLCAD file will be handy when a later version of this robot needs to know how to make other robots.
For now, though, this robot is limited to various 2xX sized bricks - 1x2, 2x2, 2x3, 2x4, and 2x8. This limits it to fairly simple models, but the concept has been proven. Actually, the concept, in a way, had already been proven by the robots that this LEGO 'bot was inspired by. MakerBot and RepRap can print any shape three-dimensional shape using extruded plastic. The plastic? It's frequently a type of ABS (acrylonitrile butadiene styrene) - the same sort of plastic used to make LEGO bricks (naturally, LEGO uses a variation on the ABS formula that is kept fairly secret). We already knew that the possibilities were endless, this was just the variation on this sort of robot that we all wanted to see.
...and speaking of which, if you want to see this in person (without building your own or a robot that can build one for you), you can see it at LEGO WORLD 2010 in Zwolle, The Netherlands, from October 22nd to October 26th, 2010.
Apologies for the late posts the past few days - I've been feeling very sick and having a hard time focusing. Things should be back to regular speed for the rest of the week, although I'm still pretty stuffy.
Details: A dutch family with three generations of LEGO enthusiasts recently built this set of animals. A brilliant mix of NXT robotics and more traditional LEGO sculpture techniques, these life-size animals act out the action in the video above. It seems like there are never enough animations that use this technique instead of stop-motion. Here, we see the animals run around in a fairly realistic manner, down to the mother duck laying an "egg" (a ball from the NXT 2.0 kit, previously known as a Bionicle Zamor sphere) and the rat taking it to eat. A surprising amount of detail went into the robots here - check out the MOCpages links above to read more about them and see photos of the source material. Also of note (but I'm not aware of more of a close-up than in the video) is some of the background scenery - the life-size squirrel sculpture and duck's nest look great too.
Some tape (vinyl) was used to cover some of the NXT parts and make the NXT colors blend in well with the rest of the models. Further "cheating" was used to make the smaller ducks work with power functions motors and a battery set-up small enough to fit inside them (they're controllable through IR - which presumably is controlled by a third party NXT IR adapter). There's another video that explains how the ducks are made.
It's been a strange week in the LEGO robotics world. It appears that community hub http://nxtasy.org/ is not going to be coming back online. http://www.mindboards.net/ has now surfaced as a potential replacement - and frankly, it's got enough of the Mindstorms community's "stars" involved that it should have no problem bringing in most of us from nxtasy. These new forums are tied to a SourceForge project that aims to gather information, tools, and software for use with the NXT (presumably other LEGO programmable bricks as well, but NXT is the main focus). The site is still in it's infancy but worth a look if you're into Mindstorms.
Details: I'm generally not a big fan of custom sensors (or so-called "lie detectors", which are notoriously unreliable), but the simplicity of this project makes it stand out as the sort of homebrew electronics activity that pretty much anyone can handle. This custom sensor can be used with RCX or NXT (although I do recommend that you use other cables instead of cutting your LEGO 9V cables - it's relatively easy to connect other wires under a LEGO 9V connector, and LEGO will not be making any more 9V cables) - it takes advantage of the fact that raw resistance is trivial to measure using the LEGO hardware. Additionally, some extra activities that can be done with this custom sensor are suggested at the same webpage linked above.
Details: This NXT-based trumpet uses a Dexter IndustriesdPressure pressure sensor with one of the older style pneumatic pumps (I believe one of the earliest ones, actually) to create a mouthpiece that responds to how far it is pushed in. That plus three touch sensors (and what I'd imagine to be a considerable amount of programming) allows you to actually play music on this.
A similar design (that isn't well documented online anywhere, but is a staple of the builder's appearances at LEGO conventions) was built by Steve Hassenplug. That one measured rotation for the mouthpiece input.
Details: Making music with the NXT can be difficult. In my experience, there's a ton of great sounds you can make with the NXT, but the big problem is getting something loud enough to be enjoyable. The difficulty in hearing NXT-based music means that only interactive music presented in small areas actually ends up being enjoyable. Here's another robot that excels in that arena - a "sequencer" that spins and makes a sound based on the color "seen" by the color sensor. Looks like fun - now if only someone could find a practical way to make the speaker louder so we could "play" this "instrument" at proper concerts...
Details: Not too long ago, the Spanish-language LEGO Mindstorms NXT blog electricBricks wrote about holonomic robots. Holonomic driving systems are systems in which a vehicle has no turning radius - it can travel in direction without needing to have a "front" that is specifically powered. In the post I'm featuring today (as well as the video above), you can see a fully-functional, stable, and practical design for one made out of LEGO. While a three-wheeled version (as suggested in the earlier post) seems like a better idea at first glance, the difficulty of getting multi-directional wheels to work (and LEGO to fit into triangular shapes) makes it surprisingly complicated and often unsturdy. This one is fairly easy to build, with only turntables as a hard-to-find part you don't have enough of in the standard NXT kit.
Details: 222Doc claims to have created the first NXT-based biped that can climb stairs. I'll have to take him at his word for that (I'm not aware of any video to prove that, and he hasn't posted programs either). His new creation, though, is even more impressive - a quadruped robot with three-toed limbs that can climb like a sloth. That's the theory, anyway - the machinery has been tested to verify that it can handle the load of lifting it's own weight on ladders in any direction, but the programming's not done yet. This isn't quite purist - you can see some multiplexers and unofficial cable used so that the one NXT can control all of the motors (looks like 8 NXT motors and 4 Power Functions motors to me). Still - this is proof of concept for a type of four-legged walker we've never seen before. I can't wait to see one of these things crawling overhead at a LEGO or robotics event.
EDIT: This is what I get for rushing posts - it turns out that there is, in fact, a video of the X2 walking up stairs, and you can see other videos from the same builder on YouTube as well. More details about the X4 sloth 'bot can be found on the nxtasy forums.
Details: It's rare that I see something that I can immediately understand all the mechanics of, but want to build one of my own anyway. This is one such model - it's a relatively straightforward construction making heavy use of beams and gear racks, and yet it looks like a ton of fun. Apparently it's even durable enough for the builder's kid to play with. Another great thing about this is that the programming is relatively simple - both an RCX and an NXT are used, but they don't actually need to communicate with each other. The end user's controls are fairly directly connected to the motors that move the claw. Do you want to try it too? Great news: the builder has posted a parts list, the instructions, the programs, and a CAD file of the complete model.
Details: Dexter Industries has been catching some attention lately in the LEGO Mindstorms NXT community for their custom accessories for the NXT. This video is of a demonstration of their solar panels, but they also make a pneumatic pressure sensor, a flexible sensor, a temperature sensor, and even a switch for a wall outlet. If you're looking to expand the capabilities of your NXT, their store isn't a bad place to start. The solar panels look pretty good in action, and apparently these two are enough to power this rover.
This is Monday's model of the day - we're still recuperating post-BrickFair, but will make up the missing days and properly wrap up this past weekend's events.
Details: Normally I try to pick a robotics-based model to feature on Monday, but today, the best recent Mindstorms item to point you toward is actually an online magazine. Generally, the magazine I plug here is BrickJournal, which is available in print and published in English. However, Hispabrick Magazine (which is published online and aimed at the Spanish-speaking LEGO fan community - and can now be read/downloaded in an English version) is increasingly becoming noteworthy as well. The most recent issue, 008, is focused on Mindstorms NXT. Several members of the Mindstorms Community Partners team are profiled, and there are also interviews with Eric Albrecht (aka Blakbird) of Technicopedia fame and even current heir to the LEGO dynasty Kjeld Kirk Kristiansen himself.
Interestingly, in spite of the Spanish-speaking focus, some of the articles cover people and models from places that don't speak English or Spanish.
In addition to the great Mindstorms coverage, there are also plenty of non-robotics articles in this issue (and previous issues) as well - so if we skip day or two of blogging here (in favor of getting more going at BrickFair), consider this to be the "model" for the missing days as well.
You can view or download the magazine in English and/or Spanish from the link above.
Now, if only we could buy Hispabrick English in BrickJournal-style print compendiums...
Although I've put off featuring them in my "another blog you should read" series, The NXT Step is easily indispensable for us LEGO Mindstorms NXT fans. It may be a difficult read for those of you who aren't technically inclined, but they do try to keep it accessible for all ages. Several of the blog's authors have written books about working with the NXT, and quite a few of them are active in either the LEGO community or the educational community. In lieu of a regular model pick today, here are three recent highlights from The NXT Step:
In other news, the LEGO website has re-posted the online bonus models for the NXT 1.0 kit. They had originally been a casualty of a website update to include newer instructions for the NXT 2.0, but the company has since rectified the error and brought them back. Now, if they could just remember that they need to re-post the bonus instructions for set 8448...
Finally, they recently found a fantastic base for a very large robot on YouTube. The tank treads are made out of Technic beams, and the 9 NXT's and 16 Power Functions motors give this plenty of expense power:
Details: Remember those scenes in Wall-E when the robotic protagonist adorably "transformed" into a little box? They've now been captured in LEGO form. How, exactly, the 3 NXT motor outputs were multiplexed into 5 9V motors, I don't know, but I think we can agree that the final effect is fantastic. One motor for each set of treads drives Wall-E around, while the other motors handle the head and arms. The process for folding the treads underneath is particularly great - three worm gears in series drive a system that actually changes the placement of the sprockets for the treads on the way underneath. Making that process one smooth mechanism is no small feat, but it works very well and adds a surprising amount of realism to this Wall-E. What makes this trickery with the tracks so realistic is that cutting-edge rescue robots that need to travel over rubble today. Being able to move the treads closer together like this allows a robot to turn around in a smaller amount of space - making it easier to navigate unpredictable terrain.
Figures that I can't find a good link to a non-LEGO robot that does that uses just two sets of treads and changes its steering geometry now, doesn't it?
Details: This batch of semi-autonomous NXT androids was also at this year's FANABRIQUES event. It's pretty common for LEGO conventions to have "themes" that are very loose and only attract a handful of theme-specific models. This year's FANABRIQUES theme was Space (which actually happens to be a popular theme that people tend to build in anyway). Taking up the challenge to bring the theme to the NXT, Matthias Paul Scholz built these two cute "astronauts" with one Mindstorms NXT 2.0 kit each. You can see in the video both a remote control mode (probably implemented via Bluetooth) and an automatic mode that passes out pamphlets.
. After following the Make Magazine blog's arduino-based attempt (that's not even all the links, but you get the idea), I was relatively well convinced that it was too complicated, since it might require dismantling the Nerf
gun itself. Not so! Today's model solves this problem with a simple cam assembly. That's before we mention the gargantuan - and yet still motorized - base, or the way this can be controlled by either a remote or NXT (done through Power Functions motors - a person can use the Power Functions IR remote, or the NXT will use a third-party IR component to control them). The video and links above fill in a few more interesting details. No word yet, though, on how you can get it to load more ammo.
replacement. Although a good deal of custom electronics were involved to make it happen, I believe this is the first NXT-based robot capable of connecting itself to a recharging station (if you're unaware: only the education edition NXT kits come with the rechargeable battery by default, but you can buy the 
when the robotic protagonist adorably "transformed" into a little box? They've now been captured in LEGO form. How, exactly, the 3 NXT motor outputs were multiplexed into 5 9V motors, I don't know, but I think we can agree that the final effect is fantastic. One motor for each set of treads drives Wall-E around, while the other motors handle the head and arms. The process for folding the treads underneath is particularly great - three worm gears in series drive a system that actually changes the placement of the sprockets for the treads on the way underneath. Making that process one smooth mechanism is no small feat, but it works very well and adds a surprising amount of realism to this Wall-E. What makes this trickery with the tracks so realistic is that cutting-edge rescue robots that need to travel over rubble today. Being able to move the treads closer together like this allows a robot to turn around in a smaller amount of space - making it easier to navigate unpredictable terrain.
