FLL and the EV3

Lego Education has started shipping the next Evolution of Lego Mindstorms Brick, the EV3. I’m excited to say that I got mine and I’m spending way to much time playing with it. Well, I also wanted to learn more about it so I started digging into various on-line resources. Some are obvious, some may not be.

Lego Education: Lego Education information (Obviously)
Links to information on the EV3: The Next Step
EV3 Programming Videos (Thanks to 4476, the Waffles: EV3 Programming Video

There’s many more sites that have information on the EV3. I’m going to try not to repeat much of the information in the sites, but I do want to give some of my opinions. Below is my EV3 in it’s default configuration as built out of the box.



One of the things I really like the EV3 sensors is that it comes with a gyro sensor. That means it can be used with FIRST Lego League (FLL). For those who don’t know, a gyro sensor can be used to determine how many degrees the robot has turned. That means teams don’t have to guess at turns, they can make their turns exact. Robots can now use degrees for driving distance and then degrees to do an exact turn.

It’s advertised that the old Lego sensor’s will work with the EV3. For the most part this is true. Most of the sensor’s I tried (i.e. touch, color, light, etc sensors) However, my distance sensor from my NXT kit didn’t seem to work as well, the distances were slow to change and would get stuck at 22cm. It could be a bad sensor on my part.

Another feature that was in NXT-G as well as EV3-G programming languages is that you can make an exact copy of a block by clicking on the block, hold the <ctrl> key left click on the block and drag. This will make a copy of the block. Quick and easy.

So far, this is what I’ve found. I’m going to be playing with it and with the 2013 field to see how it all works.

Good Luck, Have Fun, and Work Hard


FLL Stratagy – some easy targets

Easier missions are the missions that are closest to the base and with the larger targets. Attachments can make the hard targets easy as well as well as using sensors and lines or the wall to make missions close. For instance bowling, the robot can move all the way down the field, hit the wall with a touch sensor and then you know you’re near the bowling lanes.

The large video screen is the closest to base should be a fairly easy task to do. The easiest way to manipulate this is to push down the handle but to do that the robot needs to move out of the base, turn, and use some type of manipulator that pushes down the arm as it moves over it. Some other ways to manipulate the arm are:

  • reach over the screen and push the arm down
  • push up the flag
  • Or probably the easiest, go around the screen and pull the handle down.

Another fairly easy target is the blue quilts. All the robot needs to do is to push the two blue quilt squares from the base to the other two blue squares. It’s not quite a straight shot so the robot would have to push the squares out, turn slightly and push the squares to touch the black scoring area’s next to the other blue squares. Something will need to keep the squares from sliding to the side when a turn is made.

The “chair back to the base” portion of the wood working mission. should be somewhat easy. The goal is to move out grab the chair and bring it back to base. The trick is to have an attachment to grab the chair. One way may be to have a latch go across the where it would pull the chair back. Another way would be to have a hook of some type loop the chair and pull it back.

These are just a few of the strategies to get you started. You still need to do the programming and build the attachments.

Good Luck. If you have any questions, please e-mail me.

FLL – The Chassis

The chassis is the base of the Robot on which all missions are completed. The motor, the wheels, the brick are typically all built onto the chassis to become the chassis of the FLL robot. Everything here is my opinion and should not limit any design. Kids can come up with designs that over come any limitations.

There are lots of different chassis, some good and some not good for FLL. There are a lot of things to consider. Some things to consider are:

  • Number of drive motors
  • Tracks or wheels
  • How, where, number, and size of wheels for the robot
  • Caster vs. 3rd wheel, vs. slider
  • Chassis size
  • How to attach attachments
  • Make the robot go straight

Number of Drive Motors

Typically there are 2 drive motors so 2 wheels driving the robot. Another design could be one drive motor and one motor to steer the robot sort of like a car. A motor driving two wheels and a motor to turn the robot left or right. With 2 drive motors, the 3rd motor is available for attachments.

Wheels or Tracks

When thinking tracks or wheels, the missions need to be considered. Tracks typically make for a slower robot and the turn can be inconsistent because the point on the tracks that make the turn may be inconsistent. However, for traction and going over small obstacles, tracks are great.

For wheels, they are move consistent on turning, wheels are typically faster, smoother, and more accurate. Wheels can have trouble getting over obstacles.

How, Where, and Size of wheels for the Robot.

The placement of the wheels are restricted by the placement and size of the motors. With ingenuity, there isn’t a lot of restriction because of the placement of motors.

The number of wheres is a big choice. With 2 wheels your robot is a teeter-toter. If you go to 3 wheel you now have a more stable robot but could have problems with turning. 4 wheels are stable but with only 2 wheels attached to motors the wheels not driven may be drug as the robot turns, and wheels to drag to well. With 4 wheels being driven by the motors (2 wheels for each motor), there still may be issues driving.

5 wheels…hmmm. I’ve never seen 5 wheel robot, but if someone has one, send me a picture. Six wheels may be OK, however there are problems turning and dragging wheels.

The size of wheels are important, too. Large wheels make the robot go faster. However, they also make the robot larch to start and stop. Going small distances may not be very easy. It may also raise the center of gravity where it may turn over easier. The smaller wheels are slower, but more powerful for going up ramps.

Caster vs. 3rd wheel, vs. slider

If you’re going with 3 or 4 wheels, the back wheel can be a wheel, a caster or a slider. A slider is simply a Lego piece that slides around the mat. It doesn’t roll so it can slow down the robot slightly and may not be able to be drug over obstacles. Below is a picture of a robot with 2 rear sliders.

Robot slidersA rear caster using a Lego ball as a 3rd wheel. It can roll any direction for turns but it is harder to build. Below is a picture of a Lego caster.

Caster RobotA 3rd caster wheel works well for going forward. However, if the robot backs up the caster wheel may push the robot to move at odd angles. And then when it moves forward again the wheel may start the robot out at an odd angle.

Caster wheel

Chassis Size

First, the chassis needs fit in the base. Also, it needs to be the right size to move around the mat, between the missions and other obstacles. It also need to be low enough that it doesn’t fall over while moving around the mat.

Chassis Attachment Attaching

The front of the robot needs a place to attach attachments. it needs to beams with holes in in places that allow other beams to be attached. It needs to allow for quick connect and quick disconnect. Below is my chassis attachment area. It’s probably not the best but it works for me. And that’s the key, it works for you.

How to make the robot go straight.

The best way to do this is by building the chassis correctly. Here is a video that helps with how to get your robot to go straight. The wheels need to be straight up and down. If they bent out at all, it could cause the robot to go crooked. Also, one thing to give the wheels more support is to put a frame around the outside of the wheels that supports them. This is shown below on my robot. The motor is on the inside of the wheels and a frame goes around the outside. The axle that goes between the frame and motor for support.

Also, just finding wheels that are the same size is really important. Sometimes, the wheels are slightly different and that can make them turn to the side.  If you choose 2 wheels, put an axle through the center of the wheels and roll them it shows if they’re the same. If the wheels roll to one side, then they are slightly different.


FLL – attachments

I’m doing this a bit out of order, the chassis is the first thing to build. After that comes the attachments. I’ll write later about the chassis later.

Attachments are extra Lego pieces attached to the robot to accomplish a task. Sometimes motors are used for the attachment, sometimes it’s just the Lego parts to make an attachment. Some attachments use rubber bands or string to accomplish a task.

I’m going to talk about some of the simpler attachments that are not very specialized. It’s up to the kids to take the idea’s, modify them, and make them useful for this years missions.

First is a simple horizontal pushing rod. This can be made to stick out to the side of the robot to put things as it passes them.

It can push the arm down on the video calls, turn the cardiovascular exercise wheel,push over the similarity mission, push the lever of the shared ball game as it passes by the mission item.

The next simple attachment is the plow. This is for pushing cargo to it’s destination. In the picture below the plow has sides on the plow to keep cargo corralled during movement. This would be a good attachment to push the blue quilt pieces into place or after the chair has been retrieved and fixed, it would be pushed under the table.

Another attachment is a simple latch. The latch is used to drag something back to base. To use the latch the robot moves over an object, the latch clicks into position and as the robot backs up, the object is dragged back. The key to the latch is the Lego hinge is a gray connection piece, not black. the gray is designed to allow Lego movement.

A slightly more sophisticated latch can use a cage that drops when the latch is hit. It can also use a rubber band to make a cage to drop and hold. I’ll write more later about it and give a picture.

FLL Stratagy

There are many levels of strategy for doing the various FLL missions. I’m only going to talk about some of the basic strategy to start the kids thinking about how to do the missions.

The best strategy is to read the game manual. Read it closely, brainstorm with others, and think about what the description says with not preconceived ideas. For example, the Transitions mission says “Robot gets onto the center platform…”, it doesn’t say how to get on, you can get on from either end…or possibly from the side by tilting the center platform to the side and moving onto the platform.

Take a look at the game mat. In general, look at the missions to see how “easy” they are. Typically, a mission is considered easy if they are close to base or the missions with larger target to hit.

Missions such as the video call near the base, the wood working (retrieving the broken chair), retrieving the service dog, and possibly the blue quilts are fairly easy.

Missions such as the cardiovascular exercise, similarity recognition and cooperation, ball game, the lower hoop on flexibility, the orange quilt, the gardening, the strength exercise, and transitions are medium hard.They are a bit further to get to or have a small target to hit. When something is further the robot accuracy isn’t as good. Same with small targets. The transitions has obstacles to complete the mission which makes it medium hard.

The rest of the missions…the medicine, bowling, strength exercise, stove, the far video call, and the upper flexibility hoop are all hard, they are far and small to activate.

The Cardiovascular Exercise is the “impossible” mission. This is simply because there’s not really enough time to get it done along with all the other missions. It has to be visited multiple times (6 times with no touch penalties) while having to do all the other missions.

Also, there are lines on the game mat. This lines can help with movement, they can be followed to get to a destination, used to straighten the robot, or tell where you are by moving until you hit a line . Line following or robot movement until you hit a line is a strategy. The lines are a bit different this year. There are green lines, dashed lines, lines going from light to dark. We’ll have to get into the missions to tell how this will affect the game.

We’ll talk specific mission strategy next time.

Again, if you have any question, e-mail me at frc704mentor@qweztech.com.

FLL portable walls

Note: August 28 is Robot Game release…WooHoo!!

Last year I worked with a team at a school with almost no storage space near the robot room. There was little enough room for the boxes of Robot Lego’s, much less a practice table, even a portable one. We practiced on the floor on missions that were in the center of the mat with no need for walls.

This year, I don’t want any teams to fall into the same predicament. I had heard rumors of how to build portable walls but hadn’t found the plans. So I came up with the follow plans for portable walls that fit in a small storage area and are cheap to build.

It can be used for practice on the floor, or they can be taken to qualifiers and used for your own practice area.

Here’s the link – http://www.qweztech.com/OtherRobotics/FLL Floor Practice Table.pdf

It’s at my FIRST mentoring website – http://www.qweztech.com

It costs less than $25, stores in an area about 48″ X 4″ X 12″, and weighs less than 25 lbs.

I hope this can help some people. Good Luck

FLL Organizing a team

There are many different ideas about how coaches should organize an FLL team. Some of the organizational methods are good, some not as good. The key thing is to come up with a way that fits you’re (or the coaches) organizational style…unless that style is chaotic, I haven’t seen that style work yet.

These are my thoughts based on watching teams from either a mentor’s perspective or as someone who was brought in to teach/trouble shoot/guide for a short time, which seems to be something I do a lot of. I’ve also read others FLL’ers thoughts on team organization. Here are some of my thoughts.

  • The coach doesn’t need to be technical – just good with kids and organized. Understanding NXT-G programming and building helps. The FIRST organization has some good information on coaching on their international FLL site.
  • Recruit parents/mentor’s – The coach can’t do it all, you need help. They can help keep the kids on task with the project and robot missions moving. Mentors can really help with the programming and building ideas.
  • Manage and Administer the team – keep the team organized and moving toward the FLL competitions. Set practice schedule, meet deadlines from FIRST (i.e. registration, event sign up, etc.), and getting things done on time. A bigger task is sometimes managing the parents (probably the hardest part). Don’t let the parents use the FLL meetings as “babysitting”. If kids don’t want to be there, then they don’t need to be there.
  • Kid interaction – Depending on the mix of maturity of the kids, this can be tough. And, yes, there may be some crying and hurt feelings. Also recruiting the right mix of kids. Some want to be technical only (i.e. work on the robot) and some want to be project oriented. Some want to tell everyone else what to do. All of this needs to be managed.
  • Time management – have a schedule and stick to it. As an Engineer, I know the schedule will most likely be missed, but it’s a goal to shoot for. Keep the meetings on time (for the sake of the parents).
  • Area organization – There needs to be enough room for kids to work on the robot missions (4×8 ft table plus area to move around the edge, about 2 ft on each side. There also needs to be enough area for work on the project. This depends on the project, building/creating the parts of the project and area to practice. Also, a storage area for mission models, project parts, and table storage.
  • Stay connected – Communicate with other coaches and regional groups. The North Texas FLL forum is at (). Don’t go through this on your own. If you need to contact me (frc704mentor@qweztech.com) and I’ll check my contacts to find out who can help in your area. If you’re in North Texas, I can help.

Volumes have been written on coaching so do some reading.

Kid management and robot resource management is another topic. If there is only one brick (Robot Brain) this can be tough.The main thing I have is patience. Since all kids are different this is more of a coaches issues to determine how to organize the kids based on their personalities. Here are some suggestions on organizing the kids.

First, have the team come up with a basic chassis design that will accommodate attachments and can move around the field. This would include, at minimum, a light sensor for line following. Have the best builders build the chassis.


1.       My belief is to let every kids who wants to work on the robot, work on it. The robot portion FLL is organized into missions. They can be logically grouped for the robot to do multiple missions after leaving the base. A good idea is to pair up the kids and have them make the robot do a set of missions. They both work on the programming and the attachments for the mission. Not all kids have a technical aptitude but, I believe, that if they do, it should be nurtured. Also, have the kids help each other if some of them get stuck.


2.       At significant milestones in the missions, have the robot pair present what they did to the group (not every meeting). That way, every one kind of knows what’s going on and it helps toward team work.


3.       All the kids need to work on their project. Most of the time, when one pair is working on the robot, have the others working on the project. Occasionally everyone will need to work on the project for presentation organization.


4.       The kids need to work as a team. Work together, value each other’s ideas, and value each other. There will be the overpowering kids, the ones to talk a lot and telling others what to do. However, there will also be the quiet kids who think things out. These kids need to be given the time to be heard and their ideas are  listened to as much as the overpowering kids ideas. These are the introverts (which is a great thing) whose ideas will become the next Google or get a colony on another planet.


·         Los Altos Robotics (http://www.losaltosrobotics.org:8080/Main/FLL/coaching.html)

·         FIRST Lego League Coaching (http://www.legoleaguecoaching.org/)

·         FLL Resources (http://firstlegoleague.org/challenge/teamresources)

Dr. Ken Berry (Head Referee for the North Texas Region)

Get Prepared for FLL

As most of us FLL’ers know, the kickoff date for Senior Solutions is August 28, 2012. WooHoo! (link to where the material will be) Here in North Texas the Dallas Museum of Nature and Science will host a kickoff, tentatively planned for Sept. 8, 10 am to 12 noon in the auditorium at the Museum. There will be more information at the Museum FLL Link.

There are many new teams out there who are saying “what does that mean?” What it means is the field and missions will be released as well as the Rubrics for each area being judged.

For all the new coaches and mentors out, there are a lot of questions. While I’m happy to answer any and all questions, here are some links to information to get coaches and mentors started.

Official Resources:

Some other FLL resources:

Programming Resources

Mentoring and Robotics

“Tell me and I forget, teach me and I may remember, involve me and I learn.”
— Benjamin Franklin

Technical mentoring is very important in any STEM (Science, Technical, Engineering, and Mathematics) and especially in Robotics. The kids typically have the desire but not the know how. They need the proper guidance and knowledge to go forward. I’ve worked with several FIRST teams and seen various styles of mentoring. Some good some not as good. I would like there to be more of the good mentoring.

First, some general ideas on mentoring. I was looking around the web at mentoring and there was a pretty good blog on mentoring at the Center for Mentoring Excellence where there is a wealth on Mentoring. I would like to encourage everyone to read about mentoring in general.

Second are some of the things I’d like to share on being a mentor in FIRST. Here are FIRST’s mentoring resources . Here are some of my thoughts specifically on Robotic mentoring.

  1. Before the Robot season starts, get to know the kids. Talk with them what they like to do, what are there area’s of interest, and who they are. A lot of the kids won’t know much about robotics or engineering, but if they have a desire, then it will be up to you to help them explore different area’s.
  2. Share your experience with the kids – let them know how you work in the real world. What is your job like, what you work on, how you work, and how your company works. Let them know sometime you make mistakes.
  3. Talk “With” the kids, no just to them – That means listen as well as talk. Listen to what the kids are saying and ask questions to draw out there thoughts and ideas.
  4. Guide the kids in their learning – Show the kids how to do something. Get the kids to do it while you watch them Then get them to do it. Get the kids to check each others work, because here always needs to be quality control.
  5. Help keep the kids focused – Sometimes this means keep the parents and other  mentors focused, too. When it’s time to work, try to guide the conversions toward the issues, at hand. That means if your brainstorming keep the conversations on the robot and not on the days events. Leave the other conversations for later.
  6. Have fun – Try to make it fun for the kids and have fun yourself. It all goes easier when there is some fun mixed in with the work.
  7. Learn from the kids – The kids have lots of ideas and creativity and you should always listen and learn. They have a lot to give.

One more thing, always watch for the quite kids. These kids have a lot to give and don’t always know how to express themselves. Work with these kids, get them involved, and guide. Theses are the introverted kids with more to give than you can imagine. I know because that was me when I was young and I needed a good mentor to draw me out.

For First mentoring, here are some preseason reading on FIRST resources.

Mentoring is a big part of FIRST Robotics program, or any of the robotics or STEM program for that matter.

We make a living by what we get, we make a life by what we give. – Winston Churchill


Robotics – Getting Involved

I have a passion for Robotics, I want kids of all ages to be involved. If you’re a kids of younger age, typically K-12 (Kindergarten through 12th grade) you can participate on a team as a member. If you’re an older kid, Collage age and above (i.e. adults), you can participate as a mentor and/or a volunteer at an event.

For students, getting involved is fairly easy. You can either find a team that’s already started and join it. Some teams have student size limits, such as JrFLL (Junior FIRST Lego League) and FLL (FIRST Lego League). Or you can talk to a teacher or parent and start a team.

For adults, again, you can find a team and offer to help out. Most teams need adults to help out with building and programming robots, but adults are also needed to help with PR, fund raising, and dealing with kids. Adults can also either start a team or talk with a local school to about starting a team. However, be prepared for a background check.

Bottom line is Get Involved! If you need help or encouragement to get involved leave a comment or e-mail me, Joe Varnell, at FRC704mentor@qweztech.com

FIRST (For Inspiration and Recognition of Science and Technology) is my favorite because their programs span a wide age range of kids involvement, adults can get involved helping with the ages of kids they feel most comfortable with, and it’s world wide.Event volunteers are needed to help make sure teams and robots are safe, robots are built properly, the event moves as it should. Volunteers don’t need to be technical to help. If you’re just wanting to help, there’s queuing, pit administration, crowd control, and safety. If you’re technically oriented there are jobs like robot inspector.  If you’re an adult and want to work an event you can register with VIMS (Volunteer Information and Matching System) with a step by step guide at VIMS Step by Step.

If you’re looking to start a team it all depends on the age of the team. Below are links on how to started on a team of the desired age.

FIRST Starting teams

JrFLL – grages: K-3; Season Aug – Jan: <Start a team page>  <Find a team to help>

FLL – grades: 4-8; Season registration May; Kickoff Sept; Events Nov-Feb; <Start a team page>  <Find a team to help>

FTC (smaller robots, less expensive) – grades: 9-12; Season registration May; Kickoff Sept; Events Nov-Feb; <Start a team page>

FRC (large robots) – grades: 9-12; Season registration – Oct; Kickoff Jan; Events Mar-Apr <start a team page>

You can sometimes find FIRST events and teams using the FTC and FRC Find teams and event.

Vex Robotics Competition
Vex Robotics
Vex robotics is a really great robotics program based on the Vex Robotics kit. They are also world wide with lots of events.  A robot challenge for the next year is given at the Vex Robotics Championships. You then use the Vex Robotics kit and Vex parts to build a robot to compete in the competition. You can find out how to start a Vex team here. Vex Events can be found at RobotEvents.com.

Best Robotics
Best robotics is smaller and less expensive competition. You’re given a a set of supplies and a challenge. From there you build a robot from the supplies to complete the challenge. Some of the supplies are consumable (i.e. wood, PVC, etc) and some you have to return to BEST (i.e. Robot controllers, motors, etc)

A few other links events

NASA robotics competition

Robotic Events