Building Robots at School

June 5, 2012

Getting Started In Vex Robotics: What should I buy?

Filed under: Uncategorized — dtengineering @ 7:17 pm

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).

Advertisements

Leave a Comment »

No comments yet.

RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Blog at WordPress.com.

%d bloggers like this: