Aug 31, 2008

PnP - a simple "industrial" robot

Watching a typical multi-degree-of-freedom robotic arm can be a joy. Separate from precision welding on car frames, they sometimes seem to have a life of their own, and the way they seem to dance and flow is almost mesmerizing in some cases. PnP ("Pick and Place") was built for a couple of reasons - first, because it was fun, and second, because a number of folks seemed to think it would be hard or impossible.

It started as part of a challenge that involved building LEGO using only LEGO - a hard challenge in the first place, but we were trying to do it with only the parts available in a NXT kit. A lot of folks commented that this would be "very difficult" without some easy mechanism for linear motion, like gear racks... but I wasn't convinced. First, there were other ways to generate linear motion (lead screws, or certain mechanical linkages). And second, I wasn't sold that linear motion was required... so I set out to do it without linear motion, and using only three motors. I didn't finish (close, but no cigar), but what I did come up with was an elegant, and very simple way of manipulating 2x4 elements... or other parts. PnP is a two-degree-of-freedom arm, with a static mechanically leveled "finger" at the end. It can pick up and place 2x4 elements (or larger) and place them somewhere else, as well as activate levers, triggers, or slides. It could push elements together, measure element size (by pushing them against something hard, and seeing how far the arm has traveled), or it's shape (for elements of a certain size, it could be used to actually "feel" the upper profile, or determine where it balances). Since it can position the "finger" to a high accuracy and precision, the motions can be both precise and repeatable - & it's all programmed in NXT-G, with a fairly simple program (one My Block is used to move a specified joint to a specified location, with the speed as one of several variable parameters). Yes, it will maintain it's accuracy over a couple hours... in fact, the LEGO pieces very slowly separating in the framework are a bigger problem.

In this case PnP is set up as a simple color sorter - that's nothing new, there have been lots of those, many perhaps better done than this one. The difference is that PnP is much more general purpose - it could study the sequence of bricks in a pallet, and replicate that pattern from "raw materials" pallets (even unsorted ones), or determine if the pieces it's lifting were 2x4 bricks, or 2x4 plates. Since it uses only one sensor (to determine initial placement), it is free to incorporate several other sensors (like the HiTechnic color sensor here)... and it still has a motor port unused, to perform still other actions (moving the entire PnP arm along a track? Running a "brick press" or conveyor? Use your imagination). It would be very easy to set up more than one PnP arm in a row with their workspaces overlapping, allowing a robotic "assembly line" as items were passed down the row... or have a mobile pallet move along a line of PnP's to have things added on or stacked for transport.

Most LEGO robots have terribly narrow ranges of function - they are designed to do one thing, and only one thing, very well. But that doesn't have to be the case. It will be interesting seeing what EOAT's ("End Of Arm Tools") I can come up with for PnP as well, and just how far I (or you!) can take this.

Anybody want to build an assembly line?

Brian Davis

Mars Base Command - Status of Gamma

I hate to make excuses, but I've had quite a few projects going on the last few months (not just the FLL book) that have slowed me down a bit. Mars Base Gamma is almost done - almost. I was really hoping to have it completed and ready by August 30, 2008 but unfortunately it's going to get pushed into September. I originally gave myself 3-4 months for each module and got overly-optimistic that I could release them faster. Rather than rush them out the door and risking errors, I'll ask for just a bit more time to get it done.

Some details on Mars Base Gamma:

* More "small missions" - a total of 8 objectives with a better mix of easy/medium/hard
* Once again, all missions/models will ONLY require 1 LEGO Education Resource Set, no more
* Mission Mat has been enlarged just a bit and will be provided in color and black&white PDFs

Thanks for your patience - I'm almost there.


Aug 29, 2008

AlphaRex Global Roadtrip - Ljubljana, Slovenia

It's back across the "pond" for one of the Alpha Rex World Travelers... see the pictures from the Ljubljana, Slovenia visit here.


Aug 28, 2008

Not NXT 2.0... NXT-G 2.0

There have been some discussions on various forums concerning a recent web posting showing "NXT 2.0" - the rumors have started flying and some new NXT buyers are concerned that their recent purchase should have been held off...

First, it is NXT-G 2.0, not NXT 2.0. I was recently given a look at the new software and told that LEGO Education will be making it available for purchase in Nov 2008. It has built-in datalogging features, including graphs and the ability to export your data to spreadsheet applications and text files. It offers color options for the variables that are monitored, too... there's a new NXT-G block made specfically for it and the new projects are built into Robot Educator (along the right edge of the software).

That's about all I have... it is NOT an upgrade to your existing software, but is a completely new product and I have no information on pricing or licensing. If anyone is out there telling you that the MCP are sitting on NXT 2.0, please inform them that MCP 3.0 hasn't even been tasked yet with any jobs.

And if you've just purchased an NXT (retail or education version), relax... your kit isn't being phased out.

Aug 27, 2008

New Video Challenge for FIRST Teams

(Thanks to Marco at for alerting me to this announcement from Paul Gudonis, FIRST President):

At the 2007 Championship, YouTube founder Chad Hurley and I announced the formation of the President’s Circle. We asked teams to produce a YouTube video on how they help recruit and support rookie teams, and you responded with energy and creativity. I’d like to again thank all the teams who made our inaugural year a success.

And now it’s time for the 2008/09 President’s Circle.

This year’s challenge asks you to put the power of advertising to work for FIRST. Here’s how it works:

Develop an Internet Ad

Post Your Ad on the FIRST YouTube Channel by November 1, 2008

Get Your Ad Placed Everywhere

The winning videos will be announced and shown at the 2009 FRC Kickoff on Saturday, January 3.

More info here.

Copy Machine - Guest Blog

Reader Viesturs K. submitted the following on a prototype copy machine:

The purpose of this machine is to copy a black shape. On the left side is black material and table is serving as lighter material. Note it works by recognizing a fixed reflection value.

I am a carpenter and I am building a prototype of a carving copy machine. The Next test is to recognize ~6 darkness levels and depending on thecolor scanned, the cutting tool (in this case marker) will cut the programmed distance in the Z axis. For example, black/white pictures would be cut out with terrain.

Of course it can serve as printer/plotter as well, but I need to finish the program for that.

Classroom Activities for the Busy Teacher: NXT

Classroom Activities for the Busy Teacher: NXT is now available at the LEGO Education shop

You can still buy it directly from the Cafepress Store if you wish or direct from me if you're in Australia.

They've indicated that they will not be adding any new RCX resources, so if you're interested in the RCX/RoboLab version, you can only get that from the Cafepress Store.

Damien Kee

Wall-E updated!

Do you remember the amazing Wall-E build from a few weeks ago? Well Marc-Andres has updated it further and has added in movement of the eyes to the main structure. It's amazing how just a little bit of movement in the eyes can give it so much character.

From the youtube page:
SPECS: 1 NXT with rechargable pack, 3 Servo Motors, 4 PF motors, 2 IR receiver, 1 UltraSonic sensor, 1 sound sensor, 1 IRlink, 1 NXTservo module and 1 mini RC servo, 10 AA batteries and Lego from the Bulldozer #8275 and other parts from various technic sets, topped with over 100 hours of fun.
How he fits all of that into the robot, I'll never figure out!

Damien Kee

Mechanical Page Turner - Guest Blog

Reader Napoleon C. submitted the following project:

Mechanical Page Turner Design

This was a university project for my Kinematics of Mechanisms class that consisted in the design of an automatic page turner which was intended to serve as an assistive device for people with disabilities. The assignment required the identification of a page turning technique and the synthesis of the mechanism that would produce the output motion to carry out the task as well as its computer simulation. A working prototype was built using components from a Lego Mindstorm NXT kit for another engineering class to be used as the final step of a Rube Goldberg machine.

OK....NXT Ice Cream Machine : )

Aug 26, 2008

How to share the screen shots from NXT-G, MLCad, etc?

This isn't a LEGO related post. Not directly. It's about a tool that you can use to help you share your digital creations with your friends.

I recently found a tool called Jing. It's a free screen-capture utility that also does screen casting (making a video of your computer screen). I wrote about it on the Brick Labs website.

I think this would be a great utility for capturing screen shots and video from NXT-G, MLCad, LDD or any of the other digital media that we use in our travels in the LEGO Robotics world... :)

High Speed Photography with NXT

Reader Rob M. shares this:

Introducing autoHS a real commercial rendition of a NXT based device - High Speed Photography with NXT, details in the video!

First Impressions of Joe Nagata's NXT Book

I just received Joe's book and am impressed with its quality and readability.

The book has building instructions for six walking robots, plus one robot on wheels. (The two robots pictured above are from Joe's book).

The building instructions are done with black-and-white photographs and are sharp, clear and easy-to-follow.

The programming instructions are in NXT-G. Six of the robots' programming instructions are easily understandable to the English reader, despite the book being written in Japanese. Programming instructions for the rolling robot are extensive and are not easily followed by the non-Japanese reader.

Joe's book can be ordered here.

NXT Echo Telegraph

Tap out any rhythm on this simple NXT Echo Telegraph, and the NXT will answer you by playing back your exact rhythm with the NXT's speaker, as if a distant friend on the other end of the line was answering and repeating you. The program demonstrates use of the File Access block to store the rhythm timing data in a file and then reads it back out to repeat your rhythm.

While writing the program for this project, I discovered a neat little NXT-G trick. You know how you can't wire a value into a Time Wait block in an attempt to specify how long to wait (because the Wait block has no data hub)? Well, instead of using a loop and a timer to do a value-based time wait, you can use a single Sound block to play a tone with the time value wired into the Duration, Volume set to zero, and Wait for Completion checked, thus producing a silent delay of the requested time with just one block.

Aug 25, 2008

New Mindsensors acceleration sensor has released a new version of their acceleration sensor. This sensor works at 4 different sensitivity levels of gravity (2.5G, 3.3G, 6.7G and 10.0G). For more information, go here.

Aug 24, 2008

Robot Inspiration Series #7: NXT Balls in Motion

A really cool LEGO project concept is the Great Ball Contraption (video, recent blogs, Google), where you design a series of modules (general examples, NXT examples) to move small LEGO sports balls around.

Talking some inspiration from this, here is a variation that you might try for a fun challenge with your NXT set and any other LEGO parts you have to add to it: Move the larger NXT balls around, and for an extra challenge, make the motion continuous so that the balls each travel in a continuous path in, around, and/or through and back to the start of your machine without any human help. Never mind about modules and standards for multiple builders for now, just see how interesting of a way you can come up with to keep the NXT balls in continuous motion.

Here is an example NXT Ball Roller Coaster with building instructions for a single NXT retail kit that does this:

Obviously the more additional parts you have the more interesting it could get. I would love to see somebody do something cool with flexible pieces if you have some of them, for example. The possibilities are endless, really. And you don't need to be limited to a track type idea either, think of other ways to keep balls in motion. For example, this Mystery Machine keeps one NXT ball in motion in kind of a silly way, and there are lots of possibilities involving throwing/dropping/etc., as long as you can catch the balls and keep them going continuously. If you know of a link to somethink cool that does this or build something of your own, feel free to comment with a link!

Aug 22, 2008

AlphaRex's Global RoadTrip - New York, USA

AlphaRex made a visit to the Big Apple! See the travel photos here. Chris

Aug 21, 2008

That table is gonna be famous one day...

Tom W. was flipping through his new copy of FIRST LEGO League: The Unofficial Guide and got to page 15... then 16... then - WAIT A minute - flip back to 15! That photo looks familiar... he flipped back and realized his kitchen table was famous!

Seriously - Jonathan and I tried to give credit where we could for photos but this one got overlooked. Thanks, Tom, for the picture of all the nice FLL model pieces resting in their packaging... and sorry we missed crediting you. Nice table!


Wall-e NXT

Remember this post on building your own Wall-e. Marc-Andre from Canada took the challenge and build this amazing NXT Wall-e replica – it even has the original sound -:)

In Marc-Andre's own words:
This Lego Wall-E is entirely controlled via the NXT using NXT-G program. The chains are driven by 2 large PF motors connected to IR receiver. The arms go up and down individually using the 2 other smaller PF motors on another IR receiver. Both the receivers get their command thru the HiTechnic IR LINK Sensor via the NXT.The NXT servo motor are used for opening/closing of the hands and 2 more are used to move the head right/left and up/down. I have used 2 gearbox (with wormgears for the arms) and one for the head. Most of the yellow lego is from the Bulldozer kit from which i also took the Chains and PowerFunctions

More pictures can be found here.


Aug 20, 2008

FLL Unofficial Guide in stock

FIRST LEGO League: The Unofficial Guide is now in stock on Amazon... you can get it here.

If you get the book, please give us a review on Amazon and let us know how you like it!


"Jumbo" Omni-Directional NXT

Two bricks and four motors.

Nice website with plenty of ideas

Not sure how this one slipped by, but thanks to Kristie B. for pointing me to it - the site has some very nice designs and ideas to consider... check it out here.

New Blog - LEGO Teacher

A good friend of mine, Maureen, has started a new blog...

From her site's description: Welcome to the LEGO Teacher blog where I'll be commenting on the teaching of LEGO Robotics, coaching a FIRST LEGO League team, and integrating LEGO experiences into my elementary classroom in New York City.

Check it out here.

Aug 19, 2008

An Interesting Treads Design...

In preparation for the FTC competition, I've been getting familiar with RobotC, the language we're planning to use. In order to test my programs, I built a small rover that uses treads. Since the new plastic treads don't have good traction, I used the black rubber treads. Now, I don't think I've ever gotten a really good design with these treads! They're so small that it's hard to really secure them to the outside of a robot well. When I'd make a rover with these treads sticking out on both sides, I had trouble with the treads bending out and the chassis "sagging". So this time, I tried spreading the weight out more evenly, by positioning the motors directly above the treads. The result was really nice... a very strong and compact design that had no trouble with wheel camber. I even found a snug little place for the Ultrasonic sensor. :-)

Notice that the treads are connected to the robot from both sides, increasing the strength of the chassis. This is possible since the treads are underneath the robot.

I souped up the gear ratio a little, which gave the rover some pretty decent speed while not diminishing the power too much.

Here's a video of the rover in action...



New FTC Team

This year, Built On The Rock is taking a break from FLL. However, a couple of the team members and I are forming a new FTC team with some members of Team Overdrive, the World Festival robot champions from last year's FTC competition. (The other members decided to move up to FRC this year). The new robot system used in FTC, which combines the NXT with stronger, more powerful, non-LEGO construction pieces and motors, looks really nice. It makes sense too; the NXT has great processing and sensory power, but the LEGO construction system and NXT motors just aren't made for big, strong robots. Once we get our kit and the season gets underway, I'm hoping to post a lot more information about the system; it seems like it could be really useful for many applications other than FTC.

Any other NXT people out there looking at or getting into FTC?


Aug 18, 2008

Robot Inspiration Series #6: Computer-Interacting Robots

This week's Robot Inspiration might sound a little advanced: make a robot that interacts with the computer. However, this can actually be quite easy, while opening up a host of new applications. As I posted about here and here, you can use RoboRealm to easily make robots interact with the computer in a variety of ways. Now RoboRealm has added more computer capability to their software.

Keyboard: Besides taking input from the keyboard, you can make a robot control the keyboard. In other words, I could have my robot write a post on this blog! In terms of taking input from the keyboard, here's a video of a "NXT Messenger" I made using RoboRealm. With the range of BT, I can type a message up here in my room, and my mom can read it in the kitchen, two floors down, on the NXT brick!

(sorry for the low quality of the NXT screen... putting the video in the blogger player made it much harder to read the text on the NXT screen)

Mouse: Now RoboRealm lets you get the coordinates of a computer mouse and even control the mouse. Here's a video of my computer mouse controlling a cursor on the NXT screen:



EDIT: You can get the two .robo (RoboRealm) files here and here (to get them you'll need to right-click->Save Target As). You can get the two NXT-G programs here and here. Just to clarify what goes on, the .robo files read inputs from the computer and send the data to the NXT brick via BT, and the NXT-G files recieve the data and control the actual behaviors of the NXT Brick.

EDIT 2: You can get the My Block for the Keyboard NXT-G program here.

Denmark and EV cars

While I try to keep 99% of my posts relevant to NXT, this one will be a bit of a stretch - but it does involve Denmark...which is the home of LEGO. So there's your link :)

As many readers know, I'm a HUGE fan of WIRED magazine - it's Editor-in-Chief, Chris Anderson, is an NXT Tinkerer himself. The latest issue (16.09 - September issue) features the cover story, "The Future of the Electric Car" and it's a MUST read if you have even a spackling of interest in EV vehicles. As a driver, I worry about the cost of gas rising, but as a father I worry about the world my son will grow up in... so it's always nice to read about a company that's trying to do something to change the world...

The article focuses on Better Place, a new company founded by an ex SAP executive. Suffice to say, a plan is in place in Israel to move to EV vehicles - the plan is so impressive that Denmark has signed on to participate. (Apparently Denmark generates about 18% of its energy from wind power and the entire country is proud of its "green" and looking to do more.)

Grab a copy of the magazine and read it students especially, because in 10-20 years time, you'll be driving something like this (hopefully!) or maybe something even better.

Now, back to the world of NXT...


Yoshihito Isogawa - Red, Blue, and Green Books

I just received 3 books - one copy each of Yoshihito Isogawa from Japan. Un. Be. Lievable. I'll refer to the books as Red Book (RB), Blue Book (BB), and Green Book (GB) in this review.

English Table of Contents for all 3 books here:

Red Book - This is the one to start with - over 150 pages of full-color mechanisms, all using a mixture of Technic and system parts - including motors, gears, beams, and more. All the books are written in Japanese, so unless you can read it, you're going to have to use the icon system that Isogawa has created, but it's not difficult. Along the right edge of each right-side page, you'll find small icons that give you a hint of the sections' designs. For example, in one of my photos here you can see a small image of a pneumatic plunger and piston. Easy to flip to and find all kinds of mechanisms that use pneumatics. Other icons (sections) include springs, magnets, and axles. And those are only 4 icons out of maybe 12+ icons in the book. A few icons still have me puzzled, but it didn't stop me from looking at EVERY page... these small designs are incredible. There is a WEALTH of design ideas here - you won't believe it. And this is just the Red Book.

Blue Book - Almost every design in this full-color book uses tires or some sort of gear/wheel system for movement. Over 160 pages, with RCX/NXT/PF motors represented plus a few more that I don't own. Icons here look like they break the designs down into turning, rotating pieces, motors, springs, gears, pushing, pulling, and multiple-choice type behaviors. Again, some of the mechanisms are so simple but you can see where the few parts will provide major options to robots (especially in competitions like FLL). There are some gearing mechanisms in there that I just cannot figure out, but they sure do look impressive. I think what has impressed me the most is that you can see in the pictures the work the mechanism will produce as well as the small number of parts required to perform the work.

Green Book - This book, 150+ pages in full-color, appears to be dedicated to "walking" and non-wheel devices (a few exist, but not many). The pneumatics and spring sections are surprising, and I've got all kinds of ideas in my head right now. Mechanisms that use or react to sound, light, and weight (force) are also included. The first 30 pages alone are worth the book's price, as it provides dozens of walking mechanisms that could be easily incorporated with an NXT robot... some of them will make you laugh and others you won't believe will work using the small number of parts.

These 3 books are incredible. The sheer number of ideas presented in them will blow you away. While many of these mechanisms can be found in Isogawa's earlier PDF (he sells it for $10 on his website), there's plenty of original content - and the way the author has divided it up among the 3 books and then structured each book makes them easy to "read."

It's difficult to compare these 3 newcomers with the Orange, Black, and Gray books (see links below). They serve a different purpose I believe and the format is much different (very little text in RB, GB, and BB as compared to the Orange, Black, and Gray. That said, I'm much more likely to get actual usage out of these 3 new books as the building instructions are easy to follow and the mechanisms inside are more likely to offer up something I can use (although the Orange Book remains one of my favorites)

Get them here:

The author's Orange Book - more details here and here and here.

Black Book writeup - different author

Gray Book writeup - different author

UPDATE: I wanted to add that for an FLL team, these books could be indispensable. You're not going to find full solutions for any missions, but you will find so many potential mechanisms that can be made to perform actions such as pushing, pulling, lifting, lowering, spinning... the list goes on. Until a way is found to either have them translated and sold in the USA (or elsewhere), they are fairly pricey (most of that is the cost of shipping from Japan but does do a great job of delivery and providing tracking). It would be great to find a publisher willing to have these translated into English, but don' t count on that... instead, just know that the images are easy to follow and 80-90% of the designs show you exactly how to build them - the rest you can just examine the photos and reverse-engineer.

If you are an FLL team that obtains one or more of these books and you find any mechanisms that you implement in your robot, please let me know! At the end of the season I'd love to give one or more teams the ability to dissect their robot and provide a guest post or 2 covering their design, including any mechanisms found useful here.

Aug 17, 2008

NXT Olympic Record: World's Slowest 100-meter Dash

Complete with crowds, Olympic flame and fireworks.

The creator's description:

"The use of a single NXT limits the number of controlled motors to only three. In order to overcome this limitation, a special device ('Analogue Multi-Output Device') has been constructed. With this the simulated race is fully automated and no manual intervention is required.

The race takes place in steps and at a given time only one athlete is in move. Thus, don't expect that runners will complete the race in 10 seconds... this is a "slow motion" race."

HiTechnic Motor Controllers for FTC

HiTechnic's Development Lab now has information about their FTC motor controllers. I was most surprised to see that the big powerful motors actually can have rotation sensors on them, contrary to what I heard at the World Festival. This is great news, since it will probably let FTC robots have much better accuracy in pre-programmed movements.


Version 1.6 of Lemon released

I've released version 1.6 of Lemon, the LEGO® model differ.
Lemon (LEGO® Model Nibbler) is a Java application that compares two LEGO® models laid down in LDRAW or LDD format and lists the parts that are used in one model but not in the other one (and vice versa) as well as the common parts of both models.
It is possible also to check a model against the NXT Retail Kit or the NXT Education Kit.

The new version comprises a new export feature for comparison results (into a text file) as well as numerous bug fixes (in particular for the Java 5/6 version issue).

To install it, just click on the installer link on Lemon's home page (you will need to have Java installed).

If you encounter problems or want to provide feedback, please contact me via my contact page.

Aug 16, 2008

New HiTechnic Items

HiTechnic has two new items over on its website - the HiTechnic Touch Sensor Multiplexer and Power Function Programming Block: "it allows the speed of the Power Functions motors to be controlled along with Brake or Coast Mode"

Please let us know your experience with either if you'll be testing them...

NXT Pin plotter

Check out this amazing plotter that pokes tiny pin holes in paper. The creator says that can 'print' 1.3 pin holes every 1 mm.
Other Specifications:
  • printable area: 91×70mm (3.6"x2.7")
  • maximum resolution: 1.3 holes/mm (33 dpi), using a 0.3mm needle
  • time to print a bitmap of about 1,500 holes: some 35-40 minutes
  • materials: only LEGO parts (one NXT brick, three NXT motors, three NXT touch-sensors, lots of Technic bricks) except the needle
  • software: 14k of NXC commented source
  • "printable" media: 105mm-wide paper sheets (best results using 80-100g/mq paper), plastic sheets (not too thick), kitchen "aluminium sheets"...
  • NXT brick batteries: 6× 1.2V NiMH AA batteries (rated "2300mAh") allow 100 to 150 minutes printing

Full details at his website:

Damien Kee

Kit 9641 Pneumatics

Just received a 9641 kit to play with - not knowing much about the current FLL mat and models, it's a little difficult to guess how this kit might be integrated into an NXT robot. You can see in one of the photos here a nice use of pistons: raising a platform up.

I'll be curious to see if any teams use this kit - let me know if your team is planning on using it with one or more missions - you don't have to be specific if you don't want to, but if you're willing to share a photo or two of past FLL robots that used pneumatics, send it to me and I'll share with our readers.

Aug 15, 2008

Help out GeekDad!

John Baichtal of Geekdad blog (from Wired) is writing a book about LEGO. So he's looking for AFOL (adult fans of LEGO) to help him out.

He wants to include as many adult builders as he can. And he wants the most interesting folks around!

So, head on over to the Brothers Brick. for the details...

Courtesy of The Brothers Brick.

Aug 13, 2008

FLL Unofficial Guide Bookplate

I've received emails from many of you asking if Jonathan and I will sign your book. Well, distance and money are the biggest obstacle - I'm in Atlanta and Jonathan isn't... about the only way I know to do this is to bring your book to WorldFest next year and hopefully both of us will be there.

So, we've come up with another option. Click here and download the zip file that contains a TXT document. It's got an address where you can send a Self-Addressed-Stamped-Envelope (SASE) and I'll send you back a signed bookplate (a sticker - 2 inches x 4 inches") with both our signatures. Quantities are limited and anything request sent without a SASE will not be returned. DO NOT send books as they will not be returned.

You MUST include a SASE - just put your return address on an envelope, put enough postage on it to get it back to you (in the USA, just a single first-class postage stamp will do), and fold it up and put it inside an envelope that you'll send to the address provided. Allow for up to a few weeks to get your bookplate - thanks!. (The bookplate looks like the image shown here.)

MindstormsKid Robot Submission

MindstormsKid submitted a writeup for his robot, WIRE-ME, that he submitted for the paint pellet dispenser design contest:


WIRE-ME was my entry for Mercury Wire's pellet moving contest. Since they needed an average of 3 pellets per 2 seconds, I took advantage of the fact that the pellets are about a half module wide, and that a small pulley gear has six holes (you can put 2 of them on a cross-axle in a way that the holes don't align), and is also a half module wide.

I started out by making something similar to Jonathan's robot, but on a much smaller scale. I went through a few (well, more like 5 to 10) models before I realized that I would have to make a robot that had an arm (and it was only a few days before the deadline!).

I then started programming. The hardest thing was getting it to do everything (go down > pick up pellets > go up > turn to funnel > drop pellets > align) in 4 seconds. Before I started optimizing, it took about 7 seconds/cycle.

I wasn't able to do the 24-hour test because the rechargeable battery was using more amps than it was getting from the charger. I have a submission package, NXTLOG post, and extra photos on brickshelf. I also made a movie of WIRE-ME and another one with some of the other submissions in it:

Thanks to Dan and Mercury Wire for a great contest and prizes, and good job to all the winners!

Download WIRE-ME info here.

Building and Programming Instructions for RFID Xylophone

The operator plays a melody on the first "keyboard". The melody is then transmitted to the xylophone, which replays it. The creator's web site is here, roughly translated into English.

The building instructions and programming files are on the model's web site.

Aug 12, 2008

FLL Climate Connections Missions Video

I recently came across this video that shows the missions:

No embedding though... so just go to Youtube to watch it.

Add your speculation to the Forums! Just post to your topics and see what the world thinks.


Aug 11, 2008

Another thing to do with the huge green wheels...

For the Fana'Briques 2008 event in Rosheim (Alsace, France) I've built a GBC module that eventually became part of Europe's largest GBC ever.
The main idea has been to use the new huge green wheels that LEGO® released this year:

Building instructions can be found here.

Puppy dog

It's now the second time this has happened, but I've been tinkering away at a little robot design only to find a similar one found by a fellow contributors.

This puppy has 2 legs and a set of castors on the front for stability with the initial design inspired by the amazing creations of Theo Jansen. The leg design is based on a six bar linkage which I best found explained at

Getting the right link lengths was probably the trickiest part and I went through quite a few versions until I got just the right combination of step length and step height.

The stick on eyes and tail were my fiancée's idea and really give the little guy some personality.

Damien Kee

NXT++ Programming Language

NXT++ is a fairly new programming language for the NXT. Its web site and download page are here and its tutorials are here.

Aug 10, 2008

Googling NXT

Reader Simon R. emailed me a short note about searching Google:
"I typed nxt on Google and your website came up right after Lego website. I thought you'd like to know."

Thanks, Simon - we've got a good team here that keeps the blog updated, and our readers are helping now, too. I had to actually try it (see image) but you're right... it's very cool to come in right after LEGO. Now if we can just find a way to move up to the #1 position! Hmmm... :)

Aug 9, 2008

Joe Nagata's NXT Book

Joe Nagata, arguably the "king" of NXT walker designers, has published a 193-page book of his creations. The book's page on Amazon's Japanese web site is here.

Joe also has several books available here. Could someone who reads Japanese confirm that this particular book of Joe's is available on ("" doesn't provide cover images of Joe's books).

Books from Japan - More Info

More information from Yoshihito Isogawa regarding his new 3 books on Technic:

"The URL for the books as follows. The table of contents in English for
the books is not ready, so I added the sample pages on the following
The books are available from using the following URL:

Red book:
burotsuku de tsukuru kikai no hon - mawaru tsutaeru kihon no shikum

Blue book:
burotsuku de tsukuru kikai no hon - hashiru magaru kuruma no shikumi

Green book:
burotsuku de tsukuru kikai no hon - aruku iroiro fukuzatsu na

NXT "Beast of Burden"

This fully-mobile quadruped solves the problem of having to support the weight of the NXT brick. A good project for kids.

FLL Unofficial Guide - 25 page sample

The folks over at No Starch have put together a 25 page PDF file that contains some sample chapters and pages from the book - you can download it here.

NIWeek Video - guest blog item

From guest blogger Joel Sumner -

During the NIWeek 2008 keynote on Thursday, LEGO did a public demo of the WeDo software and showed some models from the kit. You can see it at this video: .

Lars Nyengaard, Director of Robotics at LEGO, did the overview, Software Manager Nicole Richard from NI presented some technical details on the environment, and then 11 year old Sara did the actual demo. The video is 12 minutes long.

Aug 8, 2008

New books (3!) from Yoshihito Isogawa

Our favorite writer and robot designer from Japan, Yoshihito Isogawa, has 3 new books coming out this month. I'll be gathering more information on the books shortly, but you can view them here.

"Based on "LEGO Technic Tora no Maki", more examples using LEGO
MINDSTORMS NXT motors and Japanese explanation were added in
these books.

The title of these books becomes "How to build machines with bricks",
because we cannot use the word "LEGO" on the cover page.

Red Book : Basic mechanisms.
Blue Book : Automobile mechanisms.
Green Book: Walking robotic mechanisms."

Reaching African-American Students

Educators working with African-American students, check this out:


FLL Unofficial Guide Shipped

I received news today that the book has shipped - this means for any of you who have pre-ordered, your order should be fulfilled earlier than that August 15, 2008 original date. Jonathan and I hope you enjoy the book!

More information about the book here and here.

Botoberfest - Atlanta, GA - September 28, 2008

Yes, Botoberfest is still scheduled for September 28, 2008. I've received some emails as well as talked to a few locals who have asked if the event will still happen. I'll try to get some more information over the next few days.

FLL Climate Connections Resources

Marco over at has updated his website with some OUTSTANDING FLL resources for coaches and teams. He's got worksheets, hi-res images of the mat, mission notesheets, and more. Direct link to the Resources here.

Robots replace teachers? Not. Anytime. Soon.

Interesting article on using robots in the classroom to replace teachers... but how realistic? Not very, I suspect.

Aug 7, 2008

NI week video on Fox TV

Martijn, one of the creators of NXT-sans Underwater Excavator, hinted to a video of a broadcast on Fox TV on NI week that touches also the NXT-sans.

The according Fox TV page can be found here.

Working with various motors in your NXT projects - Part 2

Yesterday, I blogged about the 'LEGO approved' way of powering your PF motors from your NXT - either using the IR-Link or by using the two cables you can buy from LEGO as discussed in my last blog.

Since then I have had a few comments from readers asking about how to create your own cable for PF motors to control it from a NXT. So here is instructions on how to create your own cable in 2 minutes.

Please note that this method of driving the motor from NXT is not endorsed by LEGO and also exercise caution when working with knives and cutters.

Step 1: Start with a NXT cable and a PF motor.

Step 2: Cut the end off the PF motor and also one end of a NXT cable.

Step 3: Use a sharp knife to extract the two central strands in the PF cable and the black and white strands in the NXT cable. You can cut off the remaining strands and discard as shown below.

Step 4: Remove the insulation from the strands as shown below. This is best done using a wire stripper. Don't be tempted to use your teeth - as you will get used to using your teeth and it is a hard habit to kick.

Step 5: Twist the wires together as shown. It does not matter which way (as you can control the polarity (direction) from the NXT - but if you are doing multiple wires, be consistent so you can use the cables interchangeably.

Step 6: Use an insulating tape to ensure the two exposed strands are not touching each other. Wrap it up to make it look neat. You need to tape it around about 4- 5 times so the wires dont come apart during normal use.

Step 7: Incorporate the PF motor in your NXT creations and start enjoying it!

Other Tips: If you have a soldering iron, you can use it to make the connection better and stronger by soldering the strands together. Also if you got a heat shrink, use it to give the cable a professional looking finish. And lastly, you can use the PF motor and the other end of the NXT cable to create a PF motor with NXT end in addition to a PF adopter - so you have no wastage.

If you are really experienced in making cables and got some suggestions, feel free to add your comments and tips below.

The other option (if you dont want to butcher a PF motor) is to use the PF extension instead of a motor for PF connector source: Then you could build 2 NXT compatibility cables, one of them beeing dual duty (PF and 9V). Thank you
Philo for the suggestion. Also you can read about Philo's excellent guides on creating various custom cables in his web site.

NXT "Slide Rule" Clock

One ruler for hours, another for minutes. Web site is here.

NI Week 08, NXT-sans Underwater Excavator


NXT-sans Underwater Excavator

John Brost is showing the NXT-sans, a LEGO copy of the Nexans Spider, build to excavate underwater.
The model was build By Daniel, Martyn (aka Robotica) and Eric, in the Netherlands, for demo during NI Week 2008.
The real Spider works with an Compact RIO controller by NI, this one has 2 NXT running NXT-G or Labview.

This model has 5 XL PF motors to scoop, turn and drive. Form the remote you can turn on custom LED lights.
During the first day of the event 2 motor had to be exchanged because they stopped working. YES the motors are Running UNDERWATER, but are not watertight, they are more water resistance. [DO NOT SUBMERGE YOUR MOTORS OR NXT AT HOME, because LEGO® does not replace your motors!]

It took us about 100 hours to build an program the model.

More info:
Nexans Spider:


Yellow Marshmallows and NXT

What do yellow marshmallows have to do with NXT - find out here.

Aug 6, 2008

Working with various motors in your NXT projects - Part 1

Have you ever wanted to create something cool with NXT - but the size and shape of the NXT motor made it impossible? Nearly all NXT projects use the standard NXT motors that ships with a Retail NXT kit. But that is not the only option:

Following one of the comments by a reader on my post last week about using the linear actuator, I thought I will do a blog on using motors - especially non NXT motors with your NXT kit.

The following list some ways of leveraging your motor collections and tells you how to control the various types of motors from your NXT brick:

1) Direct connection of a NXT motor to a NXT

This is the most obvious - and it is the easiest to program - either using the motor block and move block that comes with NXT-G - or a quick sequenced programmed using the on brick editor.

Given the NXT motor has a rotation sensor built in, this is the most flexible method - giving a variety of ways to program the motor action - including specifying the number of turns or number of degrees.

(2) Direct connection of a TECHNIC motor to a NXT via cable

If you have one of the common TECHNIC motor that used to ship with many recent models before Power Function motors came out - the easiest way is to use a NXT conversion cable. The cable (item #8528 at shop at home) comes with 2x2 studded connector plate on one end and an RJ12 plug on the other end. The cable also comes with a LEGO 9797 Education base kit.

This way you can use a simple Motor block to control the TECHNIC motor directly from the NXT - the motor derives its power from the NXT.

(3) Direct connection of a PF motor to a NXT

If you have some Power Function motors - from any of the latest TECHNIC and Creator models from 2008, then the PF motors are another option:

Powering it from NXT is not that simple - you need two cables:

LEGO have no plans to bring out a direct cable - so this is the only 'approved' way to power a PF motor directly with a NXT. Again programming this is just like the TECHNIC motor above - just use a Motor block and specify the length of time to turn on the motor (or you can leave it on until a sensor condition is met).

(4) Controlling the PF motors / train motors via IR-Link from a NXT

This is one of the best option for larger robots: The HiTechnic IR-link is a sensor that allows the NXT to control up to 4 sets of motors simultaneously. The motors does not derive the power from the NXT - but instead from its own PF power supply. The IR-link controls the motor using InfraRed signals. The company that made IR-Link (HiTechnic) also give you the NXT-G block so you can program it.

Edit: You can use this method for controlling both XL and Medium Power Functions motors as well as the train motors /IR-receivers that shippd with the new LEGO RC trains such as this one. [Thanks James, for the comment]

When I first tried this method a year ago, [see my review on BrickJournal) I did not like not being able to control the speed / power of the motor: The IRLink could only turn on or off the motor - you can not change the motor power - like you do with a direct connection methods above.

However, the guys at HiTechic have been busy - and recently I been playing with a beta version of a new NXT-G block that will support the Power Function PWM Combo mode. This will allow one command to control both motors and also allow selectable brake and float for each motor. I will post a link to the download location as soon as this is publicly available.

Why not drop us a comment and tell us how you used non NXT motors in your own NXT projects?

Global RoadTrip - Iceland

AlphaRex is in Iceland - see the pictures here. Now if I could only learn to pronounce those city names.

FLL mat discussion

Linda B. submitted a couple of images (one of them from Marco at - thanks, Marco). You can see her notes about the mat - comments?

Update : David Levy pointed out on the forums that also has added a zip file download for the Climate Connections worksheets here.
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