The Tethered Electric Airplane

The Tethered Electric Airplane is an aeronautical design project for high-school aged students. It was developed by Jason Brett and Todd Ablett as students in the BCIT Technology Teacher Education program and refined and expanded by many other teachers and students over the past 25 years. This post contains links to relevant documentation and starting points for teachers (or others) wanting to explore similar paths.

I have a three video playlist on Youtube explaining the project and how to build some of the equipment required to run it with your students.

The project requires a small DC motor for each plane, wound for using the high voltages (20-30V) of a bench power supply rather than the high currents provided by a battery. While you will likely find a better deal on motors at your Local Electronics Shop, my reference motor, available at the click of a button is available here, from Pitsco.

There are a few documents available to plan the project and use with your class. The first is the “Teacher’s Guide” and discusses some of the materials and lesson planning concerns. It uses the NASA FoilSim engine to help students design an airfoil cross-section. FoilSim is now referred to as “Student Airfoil Interactive” — Thanks for bringing that back from the Javascript Graveyard, NASA!! 🙂

the-tethered-electric-airplane-2014Download

The next is a shortened version of the document, that can be used as a handout, to guide students through using FoilSim to design an airfoil cross section.

the-tethered-electric-airplane-foilsim-instructions-onlyDownload

For a more advanced class, it is possible to use real, wind-tunnel tested airfoil to select an airfoil cross section. This document has information on using the Airfoil Tools database to select an airfoil.

tethered-electric-airplanes-airfoil-selectionDownload

I have recently added some 3D printed elements to the challenge. These files should allow you to print an engine mount/fuselage and tail section that will press-fit to a dowel (or even a long pencil) to form an airplane. I have shared the files to Thingiverse.

For designing multi-blade props from scratch you can use a parametric modelling program such as Fusion 360, but OpenSCAD has an algorithmic process available for creating them. Check it out!!

I have also been playing with more advanced aerodynamic finite element analysis simulation for modelling airflow over the plane in a virtual wind tunnel environment. SimScale looks promising! For a simpler, more interactive view of flow over an airfoil consider phone/tablet apps such as Wind Tunnel Free.

Every time I search the Google Play store for “airfoil” I find new apps… “Airfoil Design”, “Airfoil Analysis”, “Joukowski Simulator”, and “Aerodynamics Thin Airfoil” all look promising, but I haven’t tried them yet.

And since you’ve read this far, here’s a few photos to fill up the rest of the web page!

Good luck, have fun, and remember to wear eye protection whenever the prop is spun up!

Oh, and in case you were wondering… “Pusher Prop” designs don’t work well as having the thrust at the back tends to magnify any angle of attack errors, and twin engine designs might look beautiful, but still have to share the power coming from one power supply… hook them up in series and you get twice the resistance, and thus only half the power coming to your plane! But they can be made to work if the students put enough effort into it!

Cool Things to Go With Arduinos

I had a request from a fellow shop teacher for advice on cool things to use with Arduinos in a high school electronics/robotics lab. This is hardly a comprehensive list… and was actually thrown together on short notice… but here’s a few of the things that I like to use, or am considering acquiring.

High on my list of ‘new’ stuff is the Sphero RVR (available in Canada from Robotix Education). I like the fact that it is ‘hackable’, designed to work with an Arduino Uno, and that you can 3D print new covers for it, so you can make it into a fairly versatile drive platform. I’d get some spare batteries for it, too, particularly if using them in multiple classes in one day. For the price it seems like a pretty solid unit. I’d probably equip them with some line following sensors… I’d likely etch my own using the OPB706A or QRD1114 sensors that I have been using for 20 years, but there are newer solutions out there including single sensors and multi sensor arrays. Range finders are also useful. The HC-SRO4 ultrasonic rangefinder module is good, the Sharp IR rangefinders are good, too, particularly the Analog ones, but cameras and “time of flight” sensors are becoming more common. I’d probably add some servos or a motor control board (motor driver shield) and a nice little gear motor, perhaps with an encoder, and set it up to shoot ping pong balls or something. Oh… yeah… I’d make sure I had a couple 3D printers big enough to print new tops for the RVRs, too… and I’d probably top it all off with an LCD display shield.

I also really like blinky LEDs, and there are few things blinkier than WS2812b strips, also known as “NeoPixels” by Adafruit, which has an awesome “Uber guide” on how to use them. I also like speakers and such for making a bit of noise, and you can always hook up a small mic and turn your neopixels into a colour organ.

Adafruit has done a good job of considering “what next” after Arduino, and has some really cool Trinkets and Feathers out there that incorporate newer processors and usually a fitting for a small lithium battery. This has lots of potential for wearables.

Out of time for this post, but you can never go wrong with breadboards, power supplies, oscilloscopes, quality soldering irons, good wire strippers and flush cutters, vast quantities of usefully sized and coloured wires….

Testing A Thing

Please ignore this thing that I’m testing.

Fourth Time Rookie: Questions from a First Time Rookie

I got a few questions today from a genuine FRC Rookie Mentor. His school has no shop facilities, and while he loves science and tech, and teaches Math and Design, he’s got a few concerns about how he’s going to lead a team of students to build a 150 pound competition robot. I’ve got a few suggestions:

Kickoff 2017

1. A decade ago, I’d have said you were nuts to build an FRC robot without shop facilities, but three years ago I worked with a team where our first meeting included discussing the difference between a wrench and a pair of pliers. It’s not about where you’re starting, but where you are going. So don’t panic… that team did great and so can you.
2. AndyMark and VEXPro are your friends. They both produce a number of components that can be used to build sturdy drivetrains and actuators without welding or machining. Got a hacksaw and a wrench? You’ll be okay. In Canada AndyMark products are available from Studica.ca and VEXPro directly from VEX.
3. Learn CAD — if you can design it, then someone can build it. Very few “real” engineers actually build their own parts. They work with machinists and technicians to turn their ideas into reality. FIRST is very clear that the students do not have to manufacture every single part on the robot, so much as they should be involved in the design and creation of the robot. It is highly recommended to find local machine shops or manufacturing businesses to partner with. They can help you with the parts… and when they find out what you’re doing they’ll want to help you with the design, too. Your students will learn far more working alongside enthusiastic professionals and tradespeople than they will fuddling along trying to figure it all out on their own.
4. The programming is easier than you think. And harder than you think. It all depends what you want to do… but it is pretty easy to be a competent rookie. There are lots of tutorials and advice on how to make that work. Want a fully automated, vision tracking, PID controlled machine with a co-processor and IMU? You’re reading the wrong blog for that.
5. Come to kickoff. We’ll get you set up and send you home with a rolling chassis and a good idea of what the game elements are going to look like. All in the first eight hours of build!

I’ve seen lots of teams find lots of ways to be successful at FRC. Whatever challenge you face… isolation, funding, lack of technical skills, lack of community support, or a combination of all that and more, there is a team that faced the same thing and overcame it. You can do this. You’ll work your butt off… but that’s what makes it worthwhile.

Fourth Time Rookie: TLDR Version

Yeah, that previous post was totally “too long, didn’t read”. So here’s a short version of what has happened so far.

Last week I met with a couple of the students who want to organize the FRC team at Templeton. I gave them a tour of BCIT and showed them a few of the cool gadgets that I’ll be sharing with them this year. (Yes, we can waterjet a few parts for your team, too… but we have to plan it in advance.)

I encouraged them to do the following:

Teams make promotional materials to hand out at events. This was one of our button designs.

1. Set a date for the team’s first meeting, and then promote the meeting by:
   1. Putting notes in teacher’s letter boxes, inviting them to the meeting and encouraging them to mention it to interested students.
   2. Putting announcements in the school bulletin.
   3. Putting a few posters up around the school.
2. Make in-person invitations to:
   1. Administration
   2. Teachers from a range of specialty areas: Art, English, Business Ed, Media Production, Science, Comp Sci… all have useful FRC skills
   3. Students in grade 9 and 10 who are likely to get excited about the team and carry on the legacy. (see Lesson #2, below.)
   4. Someone who can draw, sketch, cartoon or doodle brilliantly!
   5. Someone who can sew.
   6. Someone who likes to write.
   7. And, of course… the usual future machinists, programmers and engineers who you’d usually expect to get excited about a robot competition.
3. Plan for your first meeting:
   1. Collect names and contact info from everyone
      1. Apparently e-mail addresses are a bit old fashioned… the students suggested organizing everyone via Slack. Which sounds like a good idea.
   2. Have an agenda:
      1. Show a video of the competition
      2. Discuss timelines for build season and for the competition.
      3. Discuss how the competition is about more than just the robot… it’s kind of like modelling a business around a competitive robot.
      4. Consider team names, logos, colours — look for a unified theme.
         1. How does the team name and logo match your school? How can you build it into:
            1. Uniform design
            2. Pit design
            3. Robot design/decoration
            4. Mascot design.
      5. Don’t expect everyone to agree, and don’t try to come to a decision at this meeting
         1. Listen and record all the ideas
         2. Set a standard for inclusiveness and collaborative decision making
         3. You’re going to have bigger, tougher decisions ahead.
      6. Set the next meeting date. Plan to meet once per week leading up to build date.
4. Looking for more to do?
   1. Interested students may want to start learning a 3D CAD package. I use Autodesk Inventor (free to schools) but Fusion is also good.
      1. SolidWorks and SolidEdge are also great packages… any of those four are fine, so long as everyone agrees on one.
   2. Start studying FRC team’s uniforms and pits (google “FRC Pit”)
      1. You can’t build a robot until build date, but  you can start building the following critical items:
         1. A “Robot Cart” for moving your robot from pit to playing field.
         2. A “Pit” to organize and occupy your team’s 10’x10′ space at the competition
   3. Read through a previous FRC rulebook.
      1. The game rules change from year to year, but the rest of them are pretty stable.
      2. Reading a few previous game manuals will help you prepare for this year’s game.
   4. Set up an account on ChiefDelphi (you’ll find me there, posting as “dtengineering”.)
   5. Oh, yeah… fundraising ideas. You can never have too much money.

And this brings me to rookie Lesson #6.

Lesson #6: Never name your team “_____botics.” There is another team named _______botics and they’re pretty well known. We thought we were brilliant, combining our school’s mascot, the “Trojan” with the word “Robotics” to get “Trobotics”… at least until the “Trobots” ended up in the pit next to us at a competition. Sure, we might have had the name first, but every single combination of “Robo______”, “______botics”, “Cyber______”, “Techno______” and “______tech” has been used. Yes, the Cyborg Ferrets and Technoticks are teams. If you want to check a team name for originality do a search on the Blue Alliance. You don’t have to be original, of course… but don’t fool yourself into thinking that “Trobotics” will be a unique, memorable name. Look for something that can be part of a larger theme, image, or idea for your team. In retrospect, we should have named our team the “Woodbutchers” or “TreeHuggers”… both would have fit with our wooden robots and proud, B.C. heritage and given us a theme for designing our pits, uniform and mascot. Thumbs up Hephaestus!

Lesson #6b: Don’t take lesson #6 too seriously. Name your team whatever the heck you want. It’s your team, and your name to make your own.

Observation #1: Apparently this is the TLDR version… I’d hate to see the long version!

Fourth Time Rookie: Mentoring a New FIRST Robotics Competition Team…. AGAIN.

Fourteen years ago I knew nothing about the FIRST Robotics Competition… except that I had this amazing group of students in my Grade 12 Engineering class who really wanted to take part. They wanted to “Build a robot big enough to chase Grade 8’s down the hallway.” as I recall, and FRC fit the bill. So I became a rookie FRC mentor for the first time, and together we made just about every mistake we could make. We built the robot too heavy, and had to rip it apart halfway through build, we blew up one of our four precious speed controllers, and we made a scissors lift. “Everyone makes a scissors lift…” is my actuator mantra, “Everyone makes a scissors lift once.”

Team 1346’s first match, March 2004. We had NO CLUE what we were doing. We learned… so will you!

We flew out to Toronto for the competition and proceeded to get our butts duly kicked, but in the friendly, co-operative environment that FIRST inspires, we actually figured out how to get the robot to turn (always test your robot on carpet… not linoleum or cement), ditched our floppy grippers and came up with a strategy to help our partners win. I also spent the weekend in a bit of a daze, because I couldn’t believe that an event this awesome existed, let alone that it existed for high school students and the MY students were taking part in it. It was probably the single most significant event of my teaching career.

As will happen with Grade 12 students, however, they all graduated. So when General Motors Canada called me up the following October and said, “We saw your team last year and we’d like to sponsor you.” I was the only person in BC who knew exactly how incredible this opportunity was going to be. I became a rookie coach for a second time, but was able to implement some of the lessons that I had learned the first time around.

Lesson #1: You can do it yourself, but its more fun to share. If you, or the students, can talk one or two other teachers into getting involved then you’re going to have more fun. You’ll have more ideas, more insight, and most importantly someone to kick back with at the end of the year and say, “Wow. I can’t believe we did it.” You can do it by yourself, but no one else will understand what you’ve been through. They’ll smile and nod politely when you tell them how exciting the competition was, and how helpful team 1234 was, and they’ll have absolutely no clue what you’re really talking about. Just having one other staff member involved “as your backup” will make your experience so much more enjoyable. Got an interested administrator at your school? Make them an honorary mentor, just to make sure they have to come to the competition

Lesson #2: Grade 12’s graduate. If you’re going to be a rookie team, you may as well have some rookie kids on the team. Find some promising grade 9’s and 10’s and watch how they develop over the next three or four years. At your first few tournaments you’re not going to believe that the kids actually built the robots… but when you’ve got students doing this for their fourth (or sometimes fifth) year you’ll have rookies thinking the same thing about your team. Draft some youth.

Lesson #3: It ain’t all about the robot. Graphics, media, presentations, applications, fundraising… you can certainly focus on a robot and run a small, robot-centric program based on technical skills… but you’ll be missing out on some of the best parts of FIRST. This is an outlet for artists, musicians, videographers, web designers, animators, writers, and of course, welders, machinists, programmers, wood workers, mechanics and future engineers. Just like you don’t need more teachers involved, you don’t need students doing all of these tasks… but if you’ve got the resources then go for it. We found a ratio of about 12 students per adult teacher or mentor worked okay for us, and I’ve seen successful teams with anywhere from six to sixty students involved. But if you’re just starting out, look for a diverse skill set to build upon.

Thanks to Gregg, Pat, Allan, Thane and other teachers, student teachers and volunteers who were part of the “responsible” adult quotient of our team, as well as the hundreds of kids who took part over the years we went from being second time rookies to winning awards for six straight years. We might never have been great, but we were always good. Just as the kids leave the school, however, so do teachers, and I moved on to teach future teachers at BCIT. With other teachers also considering retirement and career moves, we had to let the team go dormant, but not before it had helped create a highly competitive VEX robotics competition series that would carry on and keep competitive educational robotics alive in BC for the next decade.

A few years ago I discovered that a new FRC team had signed up, Team #5742, the Gators, at Walnut Grove Secondary. I offered to help out and thus became a rookie mentor for the third time. Unfortunately I only had a chance to meet with the team once, just before Christmas break, and discovered that they were going to learn Lesson #2 for themselves. Every kid — save for one Grade 10 student — was in Grade 12. And most of the Grade 12’s were very bright and talented science students who didn’t know a drill bit from a drill press. So I shared Lesson #4.

Lesson #4: Keep it simple. You will have much more fun if your robot does one thing well, rather than three things poorly. FRC now supplies a very functional “kitbot” chassis and vendors such as AndyMark and VEXPro supply components custom made to help build your robot quickly and easily. If all else fails… your robot can be helpful and productive in the game as long as it is moving. Save the fancy stuff for a few years down the road. Reliability, particularly at a smaller, newer regional (like BC is going to be for a few years) will be more important than dazzle.

Lesson #5: Ask for help. When we realized the team was going to need more build time than the two or three afternoons they could schedule each week, I asked for some help from my colleagues and students at BCIT and we brought the team in for a couple weekend build sessions. It was great to get off site and have some fresh eyes take a look at our problems. It must have worked… the Gators went on to win the Rookie Inspiration Award, Top Rookie Seed and finish as Captains of the #5 alliance.

Then the kids, save one, graduated and despite heroic efforts from the one remaining student he was unable to recruit a sufficient number of motivated kids. The Gators moved on to compete in VEX, thus bringing us to 2017 and BC’s first ever FRC Regional event in Victoria this spring. Although I have been occasionally heard to mention that “One should be careful what they wish for, because they might just get it.”, I’ve been wishing for a local event for over a decade and now we’ve got it. I’ve signed on to help team #7190 at Templeton Secondary, just down the road from my house, and will be blogging my experience here in the hopes of sharing a bit of experience with the other rookie coaches who are rookies for the first time. Right now you’re probably a bit overwhelmed and wondering what you’ve got yourself into. Which brings me to the final lesson for this post…

Lesson #6: It’s all worth it. If you don’t doubt that now, then you’ll certainly doubt it during build season… or maybe while organizing the field trip to the competition… or when the budget is a bit tight… but hang in there. Keep at it. Visit the other teams. Share with them and learn from them. Every single year, at least once, we (the “responsible” adults of the team) would promise ourselves that, “This is it! This is our last year! We’re done!”, and then we’d get to the competition. “Next year we’ve got to do it this way….” would become the discussion as we saw not just how our students were growing from the challenge, but how we were growing. Our students didn’t just become better students through our involvement, but we became better teachers… and shared something that until now was pretty unique amongst B.C. teachers. If you’re still reading this… well… you’re probably involved, so welcome to the club. It’s a bit crazy at times, but you’re going to love it here.

The Water Piano

Okay… this project isn’t my idea… I’ve got to thank Rob at Walnut Grove Secondary for showing it to me, and he’ll probably point out that it has been making the rounds as the “Drawdio” and other names for years. I mean, really, are there any NEW 555 timer circuits out there? Hasn’t every possible combination been made? In any case, it’s still a really cool project that can be built for a few bucks. Here’s the files:

Water Piano – Schematic

Water Piano – PCB

PCB Design_ Water Piano full sheet

The Water Piano simulated courtesy of

www.falstad.com/circuit

I’ve included 1:1 scale pdf files of the schematic and board. There is a single board to show parts placement and a full sheet of boards for etching a class set. All the information you need for parts is on the schematic.

New for 2020 is an online lecture on breadboarding the Water Piano. My students tell me it goes better with the closed captions turned on and at 150% speed… until you get to that part with important information and have to go back and watch it over.

BCTF Superconference PowerPoint Slides

The PowerPoint slides for “Building Kids by Building Robots”, presented at the 2017 BCTF Superconference are available for a limited time via this DropBox link.

Thanks for your interest, and looking forward to seeing you at a robotics competition soon!

 

Getting Started In Vex Robotics: What should I buy?

It seems to be a perennial question: “I’ve got a grant of $xxx.xx to start a VEX Robotics team. What should I buy?” I have to say it is a great question… and one I’m always happy to answer because it means another VEX team, and more kids getting a fun experience building and programming. The thing is… I’ve never got the answer “right”, at least not to my satisfaction. Part of that is because VEX is continually updating their product line, and part of that is because I keep getting good ideas and suggestions from VEX coaches, teachers and students. I’m going to put my thoughts on the matter here, but I’m also opening up a thread on this topic on the VEXforum, which is a great place to go for all sorts of VRC related information. <Edit: The form has been really helpful and posted some great suggestions… (see what ‘Sunny” and Paul Copioli have to say for some very complete and thoughtful lists) thank you to everyone who has posted, and keep the good ideas coming!>

I’m going to work on a budget of $1,500 to start one new team in VEX. As I am writing this primarily for our teams in BC, I’m going to factor in the 5% GST and 7%PST, so that quickly drops the budget down to $1,340. I’m also doing all my purchasing in Canadian funds, and ordering from iDesign Solutions as they are a great supporter of our VEX events here in BC. They’ve also been very good with their shipping rates… looking back at some of my previous purchases they have been able to ship some large orders for just $10, although speedier delivery times can cost $60 or more. In any case, I’ll set aside $40 for shipping, and work on an actual budget of $1,300. <Edit: American and overseas teams may want to look at VEXRobotics.com… I’ve been purchasing robot supplies from them and their predecessors, IFI Robotics, for almost a decade now, and they are great to work with, too.>

I should also state that although I know VEX is coming out with some new classroom lab packages and new competition packages, I am writing this as if I were ordering today, in June of 2012. Some of the links will change, as will the parts and prices, but hopefully that thread on the VEXforum will stay alive with new information and ideas.

Item #1: VEX Classroom Competition Kit with Cortex  $1,142, part number 278-2007

This is essentially just a Classroom Lab kit with the Competition Robot Kit added in. There isn’t a great savings to be had by combining the two into one order, but they are both packages that I would have at the top of my “buy” list anyway. With this package a student should be able to design a robot capable of playing the VEX game. Yes, there will be lots of parts to add to make the robot more competitive over time, but given our budget, this is all the hardware I can recommend for now. See my list of “sweet upgrades”. I also feel a bit guilty putting hyperlinks to these items as VEX has already announced that they will be repackaging and renaming the classroom lab kit with a different set of components for the fall. If you look for something on the iDesignSol.com websiteswith a similar name and price point… you’ve probably found the new kit. (Or just call up and ask Agatha, Andy, or any of the good folks at iDesign.) Note that if you are planning on starting four or more teams at once, that there are special buys available on 4-packs and 8-packs of Competition Robot Kits. Contact your supplier for details.

Item #2: Programming Software $79

There are two main packages: EasyC V4 for Cortex and RobotC. There is a thread on the VEXforum dedicated to their differences, but in a nutshell EasyC is a drag and drop interface that largely eliminates syntax errors, while RobotC is a text based language where knowing your squiggly brackets and semicolons makes a difference. If you (or your students) don’t know what I mean by “squiggly brackets and semicolons”, then get EasyC. On the other hand, if you already know your != from your || operators then consider RobotC. My slight preference (and I’ve programmed in C, Assembler, Fortan, Pascal, Basic, and a few other languages like GameMaker) is EasyC. You can download trial copies of them… RobotC here, and EasyC here and make your own call, though.

The only caveat that I’d put here is that licensing can be a real pain in the butt. Each of these licenses is a single seat licence and is easy to install by itself on a computer, so long as you have control of the computer and it isn’t re-imaging, deep-freezing, or otherwise messing up your work. If you have network installations issues, then I’d suggest talking to your IT department or finding your team a free laptop computer first.

I’d also suggest that if you are planning to expand the number of teams in your organization that you consider purchasing a multi-seat license. RobotC options are available on RobotC’s website, and include either annual or perpetual licenses, as well as the option to add their Robot Virtual Worlds package to practice programming robots in a 3D virtual environment. EasyC is also available in a ten seat licence for $397.

Item #3: Storage Boxes/Tool Kits $80

<Edit: This is one place where the forum posts have convinced me I need to change my suggestions. Toolboxes are great, but for getting started there is no reason you couldn’t hit the grocery store and pick up some ziplock containers for the little parts and a tub with a lid on it for the plastic parts. Fishing tackle boxes are another suggestion, if they happen to be inexpensive where you live. Go cheap on the storage for now, and spend the money on extra motors! (see below for link)> There is no sense buying all this stuff if you don’t have somewhere secure to keep it, and a way of moving it around. My favorite toolbox, the Stanley FatMax, is $99 and breaks our budget just a bit, but it will work well for storing your parts for a long time to come. The FatMax breaks our budget and isn’t very good at storing little parts, so maybe consider a combination of the Deep Pro for $30, and watch the KMS tools flyer to grab one of these on half price (or less) for another $30. If KMS won’t give you a deal on the metal tool box, check out Princess Auto… they have a number of different options such as this 19″ tool box. Just make sure that the inside length of the tool box is at least 18″, so that you can store your 18″ long VEX metal parts in it. If that leaves a little bit of cash left over, either purchase an extra motor for your team, or some hardware to build a VEX Robot sizing/transportation box so that you can safely store and transport your robot, and (if you build the box right) make sure that it is never more than the 18″x18″x18″ dimensions allowed in the VEX rules. If you already have part storage for your robot worked out, I’d make a few extra motors and speed controllers my top priority.

Okay… that’s my $1,300 list. Add taxes and shipping, and we’re at $1,500. Tommorrow I’ll add a “wish list” of things that I’d look for next, as the team continues to grow. <Edit… hey, whaddaya know… it’s tommorrow now!>

What Would I Buy NEXT….?

Once you’ve got this set up, you’ve got the ability to start designing some pretty complex machines… but as your skills grow and your team becomes more competitive, you’re going to want MORE…

Item #4: Foam Playing Field Tiles: $12 to $200

The next item I’d get, however, would have nothing to do with the robot at all. I’d get some field tiles. If you’ve got several teams working in one space, and have a 12’x12′ area to practice, you may as well get a full set of official field tiles for $200. But if you’re just one team, you can get by with a set of four for just $12 at Home Depot, Canadian Tire or equivalent. Having a foam surface that is similar to the playing field is absolutely crucial for testing your robot’s mobility.

Item #5: Additional Batteries: $30 to $40

Official VEX batteries are the only battery packs accepted at competition events. (Sorry, no burning the place down when you overcharge a LiPo pack!) The 3000mAh batteries for $27 seem to be the most popular on the VEX Forum… but you’ve already got an $18 2000mAh battery in your classroom lab kit. Do you want your batteries to all be the same, making them easier to change out on the robot, or do you want the extra run time (and possibly a slight bit of extra power) from the larger ones? Either way, you always want to have a fresh battery waiting and ready to go for your robot…. but don’t go crazy on batteries just yet. One spare should see you through most competitions if you are careful about keeping it topped up. Later on when you start using the power expander, you’ll need a couple more robot batteries, and maybe even an extra charger. You’ll also want a $12 spare set of batteries for your transmitter (and you’ll need a tiny little phillips screwdriver to change them).

Robot Suppliers

A recent email from Kurtis at FingerTech Robotics reminded me that there are many very cool robotics and robot parts vendors that I don’t know about. I thought it would be worth listing some of my favorites here, and then asking for posts suggesting other sources. It is a bit late for the “holiday shopping season”, but never too late to find some blingy little bits to make your next project just slightly more awesome.

Locally, in Greater Vancouver, I like Lee’s Electronics for all sorts of sensors and connectors. If you’re in the area of Main and 29th, it is worth stopping by. In fact, I’d even say it is worth going there just for a visit to see all the stuff that they have. They are very friendly and helpful, even when the store is packed and busy. I also like Princess Auto, particularly their surplus section. They have bigger stuff, and a suprisingly good selection of pneumatic components at good prices. They have a wide range of #35 and larger chain and sprockets, as well as bearing blocks, so when you are dealing with a robot drive train on a larger machine (and don’t mind using heavier steel parts) you can find a lot of what you might need in stock at decent prices. Located on United Boulevard in Coquitlam, near IKEA and KMS Tools.

As far as Canadian vendors, I have to put iDesign Solutions at the top of my list for anyone interested in VEX parts. They have consistantly had the best prices (in Canadian dollars) for VEX parts over the past five years and have been strong supporters of VEX teams and tournaments in BC.

I’ve also linked to FingerTech, in Saskatoon, which has some very cool mecanum wheels in  a size and quality that I haven’t seen elsewhere, as well as some mini-sumo chassis/kits. I bought my first mini-sumo components from HVW Tech, in Calgary, over a decade ago and have been pleased with their selection and service since. I’m not sure I’d call RobotShop a 100% Canadian operation, but they do have a Canadian presence, with a website offering sales in Canadian dollars and brokerage-free shipping from Quebec, so I guess that counts. They have a very broad range of components.

The list of American suppliers is rather lengthy, so I’ll stick to some of my favorites. Most of these will specialize in the larger, FIRST Robotics Competition (120 pound and up) size robots and parts, but I’ve bought parts from all of them and have been uniformly pleased with the product and support. I’ve watched AndyMark grow from a tiny spin-off operation to a full-fledged business designing and creating some of the coolest “big robot” parts out there. They have a Canadian presence, so if you prefer to purchase in Canadian dollars and have things shipped without brokerage fees, ask them if they can help you out in that regard. Check out their gearboxes (mostly build around the indominitable CIM motor), and wheels… but they have much more than just that. The VEXPro line of components is very cool, too. Their ARM9 controller is on my “wish list” of cool robot stuff. For motors and planetary gearboxes in all sizes and ratios, I recommend BaneBots. I have to also recommend Trossen Robotics as they saved our bacon once in FRC by having the last 32:1 planetary gearbox for a speed 500 motor available in North America. They FedExed it to us overnight and while the shipping cost more than the gearbox, our machine was up and running by the end of the week.

You’ll see me refer to Polulu elsewhere, but they have not only about the cheapest prices that I’ve been able to find on the Tamiya gear boxes, but also a whole swack of other cool stuff, mostly for smaller robots and electronics projects.

Digikey is also a favorite place to shop… they take Canadian dollars and deliver, brokerage-free, faster than a neutrino in an Italian mountain. They also stock the Jaguar motor controller, probably one of the coolest speed controllers on the market.

Like I say, this is hardly a complete list of cool places to buy robot stuff. The Calgary robotics club has an even more comprehensive list, and I’m hoping people will post links to their favorite shops in the comments section. I have a great admiration for all those entrepreneurs who have turned their robot passion into robot profits and am happy to support their hard work and innovation.