Frequently Asked Questions (FAQs) of the Official Stiquito Homepage

Stiquito is a small, simple, and inexpensive six-legged robot that has been used as a research platform and to teach science in primary, secondary, and high school curricula.

This page is simply a "stream of consciousness" of Stiquito, building Stiquito, and using Stiquito. There are actually questions and responses from emails. The major categories are"

Supply of Books and Kits

Q: Where can I buy the books?
A: Most large book store chains and online stores sell the book. We sell signed copies of the books here (follow this link). We have found that most places have about the same price for the books, even when you factor in shipping. Of course, not all books will be signed :-)

Q: Where do I find additional Stiquito kits?
A: The Stiquito and Stiquito II kits are sold from our website (follow this link)

Q: Where do I buy the kits described in Stiquito for Beginners?
A: The Educational, PC Parallel Port Controller, and Analog Controller kits are sold from our website (follow this link). This are the only known sources of these kits.

Q: My Stiquito broke. Where do I get extra nitinol/aluminum/music wire?
A: You can buy a Stiquito repair kit from our website (follow this link). You can also visit a local hobby shop to get wire and aluminum. Nitinol is sold here and also sold by Dynalloy, Inc. (but in large quantities).

Q: Where can I find brass screws?
A: A kit of enough brass screws, washers, and nuts to build Stiquito are sold from our website (follow this link).

Q: I am a professor/teacher/poor student. Can I get a examination/free/gratis copy of the book?
A: In the book industry, many college book publishers shower professors with books in the hope that they will adopt the book. The publisher of Stiquito books, IEEE CS Press, is not a college book publisher. Their policy is NOT to provide desk copies of any of their products, including the Stiquito books. This is one of the reasons of why the book costs less than most college books, despite having an expensive robot kit inside. If you want to try, contact the publisher, but good luck!
I buy the books that I sell on this site. I do not give away things that I pay a lot of money to buy. Sorry!

Assembly

Q: How old do you need to be to be able to build Stiquito?
A: I set a age of 14 years for the typical ability to build Stiquito. Some younger are successful, some older fail.

Q. What kind of problems did you have when you made Stiquito?
A. I (Jim Conrad) am not the inventor of Stiquito, but I took the inventor's idea (Jonathan Mills) and made it easier to build. In the first version of Stiquito, you would have to cut plastic, drill holes in it, and glue it together. This was hard to do. I created a single piece of plastic which helps the builder from having to drill and glue.

Q: Is Stiquito's battery attached to the robot or away from it?
A: As Stiquito is packaged in the book (with manual controller), it is attached away from the robot.

Q: For my science fair project, I have decided to build Stiquito. My father and I spent many weeks carefully constructing the robot. The robot seems to work perfectly fine when it is turned over on its back. When I went to test the robot, I found a little problem. When the legs dug into the table I had it on, it would move forward. But, when the muscle wire cooled down, it just moved back to where it started from. The robot seems to have the potential to move, but it is not on the proper surface to do so. Is there a particular surface that would be better to use?
A: Smooth surfaces do not work well. Something a little rough is good. A sheet of paper is good, or even 600 grit sandpaper. You may want to add some weight to Stiquito to allow it to dig into the paper. Oh, make sure the feet are at the correct angle (110 degrees).

Q. Once a person has completed Stiquito, what do you think is the most important thing to have learned?
A. Obviously they need to be patient to complete a happy, walking robot! There are many things they learn, like there is a cost/effort relationship in building robots. A more expensive robot could be build in a shorter time (i.e. Lego Mindstorm). Considering that the Stiquito robot costs about $3-$4 dollars in bulk, one can afford to spend lots of time and discard failed attempts - if the builder has more time than money! Remember, Stiquito is just a platform for testing electrical circuits and software, it is not the "end result" of robotics experimentation. Uses of Stiquito are only limited by one's imagination.

Nitinol

Q: What is the maximum current that the leg can take before going to slack?
A: The question should be broken in two:
"How much current will nitinol use?" Everything it can get. If you provide 50 mA, it will use it, 150 mA, it will use it. "So what stops nitinol from consuming current?" Nitinol will stop working when it destroys itself by heating too hot (by consuming too much current). It will typically melt.

Q: I would like to control the robot movement. Is current control better or do I stick to voltage control?
A: Based on the above discussion, current control is much better. Remember, nitinol actuates by heat, heat comes from current.

Q: Is it true that I should not give the supply for more than .5sec per movement?
A: If you can control the current (i.e. Pulse Width Modulation) and ensure you will not overheat the wire, then you can supply current to nitinol forever. Just don't melt it!!

Q: I'm interesting in building a robot with nitinol wire but I'm confused with the nitinol wire spec. I guess from your web pages that the Stiquito use the 0.004" Nitinol wire or smaller. My project may need bigger wires than that but the nitinol wire spec show that the bigger wire will have much slower "off time". Does the off time mean how long the nitinol wire take to go back to normal condition (room temperature) after we stop heating it (with electric current)? If I'm correct then does it mean that building robot with big nitinol wire is not practical because it will be too slow?
A: You are correct in your observation. Some ways to speed up the cycle time are:
1) have air circulate over the robot
2) control the nitinol so that its heated temperature is just over the contraction temperature - it will cool faster.

Applications

Q: To avoid friction how do you like the idea of lifting the leg little (using the extra holes provided) before the actuators come into effect?
A: I have a version of Stiquito that lifts the leg with another actuator wire, using the extra set of holes (that's why I put them there - for the flexibility of the designers).

Q: I was wondering if you have seen anyone fit Stiquito with a solar powered kit (so he did not try to carry that heavy 9 volt battery)?
A: The analog kit that is in the book requires 5v or more continuous voltage. A solar cell cannot provide the voltage/current needed. You could design other circuits that use capacitors, and charge the capacitor up to the needed voltage, and then "fire" the stored energy through the nitinol. This is the "B.E.A.M." model of mini-robotics. This is described in Chapter 16 of the advanced book, but you can also search the web for detail.

Q: I understand that if we use the manual controller, which just seems to be on/off switches, we would need to wire the Stiquito for, e.g., tripod gait. If we use the analog controller can it be used to control a Stiquito which has the legs independently wired? Or would you recommend that we just wire our first Stiquito for a tripod gait anyway, and experiment with independently wired legs on a second Stiquito?
A: Lucky for you, both the analog controller and the manual controller gaits are the tripod. Therefore, if you wish, you can build the Stiquito with a three pin header which can plug into the analog controller OR the manual controller (you will have to build the manual controller with a three pin socket instead of crimping directly to the Stiquito). We have extras of these sockets.

Teaching

Q: IEEE literature describes a teacher's manual associated with Stiquito for Beginners: "Also available: An accompanying teacher's manual including additional experiments with science benchmarks and national standards associated with each chapter" Where can I get a copy of this manual and what is the cost?
A: There two sources teachers material:
* The "accompanying teacher's manual including additional experiments with science benchmarks and national standards associated with each chapter" is actually available online. Go to the publisher's online supplement, Stiquito for Beginners page. You can download a single word document, or look at each chapter separately.
* The other would be the solutions to the book exercises. That I have not completed yet, and so few people ask for it that I may not actually do it. If you are interested, I can always trade your time for free stuff! The first four chapters are done. Go to the online supplement for ordering info.

Q: I'm sure you've worked with other school that have used this in a classroom before....ever hear back from them....they seem fairly delicate to work with? Has that been a problem for high schoolers?
A: High school students are able to work with Stiquito . . . as long as they are patient and have worked with hobby kits before. I recommend the Beginner book, PC Parallel Port kit, and ESPECIALLY the screws (easier to build). See the screws and PC parallel port kits offered from our website (follow this link) for more detail. I have talked with a 5th grade builder, so some younger builder can use the kit.

General

Q: My 14 year-old son is a robot nut. He has the Lego Mindstorm Robotics gear, wants to study Robotics in college and desperately wants the Stiquito For Beginners Book and kit. I was on your Web site and noticed that your location is about 3 hours away from my home. In looking at MapQuest, it appears that you are operating out of a home, but on the off chance that there is a store or warehouse, where he could come and revel in robotics, I thought I would ask. Do you have (or know of) an actual Robotics storefront?
A: Sorry, there is no "real" Stiquito place with a storefront and show room. I am basically selling little bits of this and that from my home. There are no real "robotics" storefronts that I know of in the US.
     My recommendation is to (of course) get the Stiquito book. Next, he should get involved with the FIRST contest, if possible. This would involve getting his high school paired with a corporation http://www.usfirst.org/
     There is also the trinity robotics competition he might want to investigate: http://www.trincoll.edu/events/robot/
     Check your local area for robotics clubs. We have one here in RTP: http://www.triangleamateurrobotics.org/

Q. What do you think is the most important piece of information about robotics to include in my presentation?
A. Robots of the future will come in many different shapes and sizes. Big ones will help assemble machines and make products. Smaller ones will clean our home and cut our lawns. Tiny ones will eat farmland pests and travel in our bloodstream. The future of robotics is bright; we just need more people to learn about the underlying technology in order to design and build these robots.

Other Stiquito Sites - Projects

	Go to the Stiquito Controlled support site for code listings and other TI MSP430 information.
	Christian Lehner, Berlin, Germany: "I recently ordered the Stiquito kit and designed a little controller as a replacement for the original plastic body. Using the Atmel micro controller and a Darlington array, the little robot can walk autonomously."
	Jim Conrad taught a Stiquito/Microcontroller course Summer 2001. On August 6, at 7:30p.m. in NCSU Daniels Hall the class raced their robots. Take a peek at the NCSU ECE 292B course notes, syllabus, and photos.
	For more information, go to the IEEE CS Press Stiquito Book On-line Supplement. This page contains additional information about Stiquito and the Stiquito books, and is sponsored by the publisher.
	The students at Texas A&M University have made some rather interesting variants of Stiquito. Take a look at this picture.
	Pictures of Cosmin Rotariu's Stiquito-like robots.




	Send your web site info of Stiquito projects to: jconrad@stiquito.com