Monday, November 30, 2009

Useful Lego

I found this pic on There, I Fixed It.  I thought it might make you smile.

Candle Making Kinetic Art

I considered building a robot that makes candles. This would be done by dipping the candle in different colored wax using some sort of overhead gantry to create a multicolored effect. Then using some sort of CNC lathe to create different diameters that would show off the different colors.

Then I get on YouTube, a natural source for learning and ideas. I didn’t find any real good “How To” videos, but I did find one interesting video. Someone actually turned the task of dipping candles into a sort of kinetic art.

Amazon Deal on NXT 2.0

Pretty good deal on NXT 2.0 from  $227.99 for the set.

Sunday, November 29, 2009

RobotC 2.0 Now Available.

After what seemed to be decades, the programmers of RobotC have announced they have finally released version 2.0. If you know anything about the program, it has been updated in the 1.xxxx realm many times and sometimes created more problems than were fixed. If you have paid the $30 for a previous version, the license is still valid and upgrading is free. If you want to try RobotC, you can download it and use a fully functional version for 30 days before you are required to pay the $30 license fee.

RobotC is my preferred programming environment when I need more power than can be found in NXT-G. I always recommend it, but the only real drawback I can say is that they don’t support Bluetooth communications between more than 2 NXTs. I am getting ready to download and install it, so I can’t really speak too much about the upgrade. In the past I have been pretty happy with updates, so moving up to 2.0 should be pretty easy and rewarding.

The upgrade can be done through this link.

From the RobotC website.

ROBOTC, a C-Based programming language for robotics
ROBOTC is the premiere language for educational robotics. It is a C Programming Language with an Easy-to-Use Development environment. It supports several different robotics platforms, including popular platforms such as the LEGO MINDSTORMS NXT and Innovation FIRST VEX. Download its blazing fast, High Performance Firmware to your robot. Using its Interactive Run-Time Debugger, you can easily pinpoint the problems in your programs. Try it out today by going to the Downloads section and choosing your platform.

Learnin' for Free

I found something incredible. The Ministry of Human Resource Development for the government of India has funded a program called The National Program Technology Enhanced Learning. It is an extensive program to help people get training in technology. I haven’t investigated the full reach of the program, but I have looked through the videos on and it is very impressive.

Incredibly, they have posted 4,251 videos. Most are one hour classes on different college level classes covering 117 different topics. Basically, it is a full college education on video free for everyone. All the videos are surprisingly in English, but the professors are Indian. Some are done very well, others not so much.

The list of topics looks just like a syllabus from any university. They include Electrical, Mechanical, and Civil Engineering, Mathematics, Physics, Computer Science, Electronics, and on and on. I have a couple that I am particularly interested in; Mechanical Robotics and Mechanical - Kinematics of Machines.

Here is the playlist for the entire program.  Very impressive.  To give you a taste, this is the video for Introduction to Robotics.

Friday, November 27, 2009

Thursday, November 26, 2009


This is a pretty cool robot. I have thought about building a bot that shoots, but haven’t really figured out a good way of locating the target. Shooting at a light source or something might work.

The best part is the builder gets shot at by his own creation.

Monday, November 23, 2009


Some years ago, I worked several times (mostly unsuccessfully) to build a pendulum clock. I had no problems with the hand movements, the gearing, the weights, the pendulum, the structure; I had it all figured out. But I had lots of problems working out the escapement. An escapement is a device which converts continuous rotational motion into an oscillating or back and forth motion. This creates the familiar tick tock sound.

Very generally speaking, the pendulum, the weight and the escapement work together to create the power of the clock. The weight pulls on a drum which turns the escapement wheel. The escapement wheel transfers very small impulses of force to the pendulum to keep it swinging. The pendulum will always swing at a constant pace or period, thus a pendulum is a great way to keep accurate time.

The tricky part is creating an escapement that will work regularly, have enough power to keep the pendulum swinging, and not too much so the pendulum is over powered and swings wildly. YouTube user BenVanDeWaal seems to have this problem licked. It seems he has devoted his entire Lego building existence to building escapements, and I might say he has done a very nice job.  He has several videos of several escapement types, but here are a few of my favs:



There are many more, and if you like these, go visit BenVanDeWaal's site.

Wednesday, November 18, 2009

Short Dry Spell On Posts

Sorry about the short dry spell on posts.  We are dealing with the flu bug all around us, plus I am preparing for an interview for a really great job.

But here is a neat video of some non-robotic kinetic sculptures.

Be back soon!

Friday, November 13, 2009

Friday's Idea-Omnibot

Omnibot was every boys dream in the mid 1980’s. If you had one, then you also had a complement of jealous friends, me included. Just another example of how 25 years takes away the feeling of “I have to have one” and replaces it with the feeling “I don’t want that junk, I have something much better.”

Building this out of Lego would be pretty cool, and the best part is that we could make it with many, many more functions.

Thursday, November 12, 2009

Mechanisms and Linkages

As I have mentioned over and over, I am a fascinated by motion and movement. I have posted a few kinetic art videos of which I am a huge fan, and there will be more. A few of my favorite classes in college were Kinematics, which is “the branch of classical mechanics that describes the motion of objects without consideration of the causes leading to the motion,” Dynamics, which is “the mathematical analysis of the motion of bodies as a result of impressed forces,” and the course that applies the two in real world applications, Kinematics and Dynamics of Machinery.

Much of the applied course was devoted to linkages and mechanisms. There are several classes of linkages and probably hundreds of named linkage arrangements. I own several books which verbally and mathematically describe many of the linkages. I get a kick out of looking at a machine and finding a linkage or mechanism that I recognize.

But I have a feeling that many of the linkages and mechanisms will be replaced by more mechanically simple servo motors and linear actuators. If you look at old machinery, you will find all kinds of cool movements generated by cams, levers, mechanisms and linkages, but with robotics and complex mathematics, some of those devices are obsolete. But they will never go away, and even more complicated linkages are being developed which I really like.

You can find tons of videos of many of linkages on and similar sites. One of my favorites is of course Theo Jansen’s Strandbeest.

The Strandbeest has been duplicated in several mediums including Lego. I’m not going to link to any of those videos out of respect for the artist, but some of those are quite impressive as well.  If you are not familiar with Jansen and the Strandbeest, I highly recommend visiting the link.

I have found several really interesting pages devoted to sharing linkage and mechanism designs and graphics. Here are a few;

RoyMech. This is a detailed page including all kinds of engineering resources, but my favorite is Mechanisms.

KMODDL. “KMODDL is a collection of mechanical models and related resources for teaching the principles of kinematics--the geometry of pure motion. The core of KMODDL is the Reuleaux Collection of Mechanisms and Machines, an important collection of 19th-century machine elements held by Cornell's Sibley School of Mechanical and Aerospace Engineering.”

Brock Institute for Advanced Studies. This page shows animated graphics for several linkages.

Kanagawa Prefecture’s Linkage mechanism simulator is a downloadable linkage simulator.

Tuesday, November 10, 2009

Roomba Pac-man

The Roomba is a robotic household vacuum cleaner. It’s a favorite hacking target of some people and you can find several blogs and videos around the net. Most of them are pretty lame compared to even a basic obstacle avoidance NXT robot. But this one is pretty cool and very complicated.

It would be way over my head to program, but nonetheless, fun to think about building with a full set of NXTs.

Sunday, November 8, 2009

Feel Good Lego Article

Completely not robotics or engineering related, just a great feel good story about Lego and family interactions.  I have a 4 year old who just points at the drawers for what she wants.

A Common Nomenclature for Lego Families

Saturday, November 7, 2009

HiTechnic Infrared Receiver

HiTechnic has posted a video demonstrating their new HiTechnic Infrared Receiver along with a Lego Power Functions Remote. They have built a pretty cool car with Ackerman steering that as demonstrated is pretty impressive.

The description reads as follows;
The HiTechnic IR RC Car features the new HiTechnic Infrared Receiver. This sensor makes it easy for you to control your creations using a LEGO Power Functions Remote.

This model is based on the LEGO Mindstorms 1.0 set. It also requires a LEGO differential and that is not part of the Mindstorms set. If you do not have a LEGO differential, you can go to and search for "Gear Differential", the part number is 6573.

Remote control - Using the HiTechnic Infrared Receiver and LEGO Power Functions Remote

Steering uses a PID controller Both NXT-G and NXC sample programs implement a PID controller to steer to a specified target position.

Ackerman steering - Which means that it has a steering geometry so that in a turn the inside front wheel turns sharper than the outside wheel.

Geared up to differential - Geared up 3:5. The drive motor has a 40 tooth gear driving the 24 tooth side of the differential.

Building instructions and sample programs can be downloaded from

Friday, November 6, 2009

Fridays Idea-Lego Music

Most of us have seen the video of the mildly cool Lego Band.

There have been a couple of computer generated versions that generated a little buzz.


But my favorite by far is one that was actually built. It was also done on very large scale apparently as an advertisement for Absolut Vodka. It’s a version that uses mostly flying balls, but also a little percussion and some wine glasses.

Obviously this would be an incredibly difficult build. One would have to not only know Lego robotics, but music and some physics as well. But I think it would extremely impressive.

Wednesday, November 4, 2009

Secret Knock Detecting Lock

If you haven't figured me out yet, I love to post projects that I think could made using the Lego NXT system.  I found one today that is pretty cool.  More inspiration.

I don't see many projects using the sound sensor, so this one is pretty special.  Just keep those batteries charged, or keep your key handy.

This is why I am not going to Robodays...

Look closely at 0:20.  Hollywood magic at it's worst.

Monday, November 2, 2009

Lego Lip Synching Robot

I just posted my latest creation. I take no credit for the idea, I posted a version earlier in my blog. It is programmed in RobotC and uses simply one sound sensor and one servo motor.

It was a fun build, and I think I will be able to use it in future projects.

Sunday, November 1, 2009

Talking Robot

Wow, I just saw this simple little project a guy built, and I thought it would be pretty simple to make with a NXT, a sound sensor and a motor. Set the motor to position the mouth open or closed based on the intensity of the sound. Pretty neat.

If anyone does this, I would love to show it off, so let me know.

Update: I have already built one of these. It turned out pretty well. Am working on a video now and I expect to have it in a day or two.