Newbie looking for help

Hello

So I am looking for a Christmas gift for My wife and ran across Vex. She has mentioned several times that she would enjoy building a robot. This isn’t as crazy as it sounds as I am very mechanically inclined and my wife is a software engineer although we have 0 robot experience. So my questions are:

  1. Is vex the robot build kit for us? If not what is better and why?
  2. If vex is the system what do I need for a reasonable start?
  3. What is the difference between PIC and cortex?
  4. I assume the software package is required for any programming?

I have cruised the forums and vex site already. I looked at the basic vex package but it seems quite limited in build potential. I also looked at the basic classroom lab package and it looks much better but does cost 1k which seems a little steep. Also neither package has anything but simple sensors and no arms. Can you do much without the fancier sensors and a claw arm?

Thank-you in advance for your comments.

I’ll leave answering some of the other questions to others.

Vex is not cheap. Any one who tells you otherwise, is far richer than I, and probably far richer than most people. On the other hand, it is a very flexible system and I would say it is worth it if you don’t want to custom build parts. If however, you are willing to fabricate your own metal components (which I assume you are) then I would recommend attaching your own pieces to the existing Vex system to save on costs.

Yes is the short answer. Take a look at some of the robots from established teams and you’ll discover that it’s not the materials that are the limiting factor, but simply time and innovation. Claw arms are easy to make out of Vex, as the motors are small enough to be mounted at crucial pivots (and of course you can use chain and gears to translate the pivot point from the motor to the start of a claw).

There are other systems out there, yes, but for starting from scratch, I think Vex has an excellent learning curve to possibilities ratio in that it is easy to pick up, but very hard to master. Those that do achieve great results almost never reach their full potential (at least in competition use, simply due to lack of time), so it should keep you satisfied for a long time.

Edit: the fancier sensors are very useful, but can be picked up in individual packs. I would recommend you get some of these.

//not supposed to be a marketing post per se

Very possibly. I would call it appropriate for adults that want to build robots but don’t have the experience or equipment to fabricate all the parts themselves. I’d say it is a better fit than Mindstorms would be. And it is a complete system, but isn’t so proprietary that you can’t interface non-Vex parts and sensors.

Vex’s core customer base is high-school level robotics competitions, but there are plenty of us hobbyist types that just enjoy tinkering, and I find it to be a good value.

I don’t have a ton of experience with all the other systems available, but another one to consider is the Servo Erector Set system from Lynxmotion. It isn’t as complete a system as Vex, but it is pretty nice.

Depends on your goals, but I’d start with one of the classroom starter sets and buy additional bits as you find you need them.

I posted a comparison of the microcontroller options on the wiki. At this point, I’d recommend the Cortex unless you have a strong reason NOT to get it.

In fact, since you are not constrained by competition restrictions, you might consider going straight to the VEXpro microcontroller. It is a good option if you are focusing on autonomous or tele-operated designs, since the joystick remote isn’t supported with it yet. Here is a cost breakdown of programming the VEXpro -vs- the Cortex.

You need programming hardware and software for the PIC and Cortex controllers. The VEXpro only requires a wifi connection to program it, and the IDE is a free download.

Most of the competition robots use very specialized intake mechanisms for handling game elements. Generalized claws are not very typical for Vex robotics, though the two finger gripper they sell is a nice place to start.

I think if you really add up what you get (the build quality is very nice), you’ll find it hard to beat the 1K price tag by much elsewhere.

Cheers,

  • Dean

I mean I personally love Vex, but there are other options I agree VEX is a little expensive, I would recommend using the PIC if its not for competition and you don’t mind the bulky controller. I would recommend starting with the Classroom Lab Kit with PIC (699.99) but if you find that is a little over your budget you could always go with other options I’m not quite accuainted with very many others but one I really like and personally own is LEGO mindstorms NXT. This has a lot of programming capabilites and though it is eaiser to program then VEX still has a lot of sensors that work really nice. You can do some cool things with it too, but its not metal you build it out of lego and its much more affordable. Check http://mindstorms.lego.com/en-US/default.aspx?icmp=COFranchiseUSMINDSTORMS
and
http://shop.lego.com/en-US/LEGO-MINDSTORMS-NXT-2-0-8547
out for more information

This sounds like a great idea! Vex is a pretty good system if you want to start out simple and work your way up, as there is a lot of potential to be unleashed with the system. If you want something even simpler, you could try the Lego NXT Mindstorms system, but that is much more limited in terms of capabilities than Vex. To get something more complicated, you could get an Arduino microprocessor, and buy other parts from your local hobby shop such as wheels, and custom build your own parts to develop a chassis etc. I think that Vex is a good fit because it sits somewhere in the middle between the two systems.

A protobot kit will be plenty to give you a reasonable start. I’ve recently been involved in trying to use this equipment for education, and have found that the starter bundles are actually pretty good for the price. It does depend on if you want your robot to only be autonomous, or if you want to support driver control as well - the starter bundles are here: http://www.vexrobotics.com/products/vex-robot-starter-bundles/cortex - the dual control bundle is $550 which is a pretty good price considering it will have just about everything you need to get started. Vex also sells a lot of things separately, so if you later decide that you want to increase the capability of the robot, you can purchase the individual parts and packs as well.

The PIC is basically an older and simpler microcontroller, whereas the Cortex is the newer one. They have similar programming capabilities, but the Cortex runs faster, has more input/output ports, supports a much wider range of customisation such as I2C, and is in general better, which is also why it’s more expensive :stuck_out_tongue: If you’re not expecting to want to do too much with your robot, then a PIC is sufficient for most applications. However, the Cortex will provide much more potential for increasing the complexity of your robot. There is also another microcontroller available, called the VexPRO ARM9 - this is an even more advanced piece of equipment that has a completely different programming system but is capable of much much more and is suited for advanced users. Depending on how ambitious you are, you could go for the ARM9, but there isn’t that much support out for it yet as it’s quite new. I would personally recommend the Cortex because again, it’s a good balance between complexity, potential, and price.

Finally, if you buy one of the starter bundles, you will get to choose which software package you want to include. While there are a couple of other options such as MPLAB or PICs available, most users use either EasyC or RobotC. EasyC has a graphical interface which allows block-based programming, whereas RobotC is text based. Since your wife is a software engineer, I think RobotC will be a much better fit there.

Hope that all helps! Let us know how it all goes, everyone here is always interested to hear how others are finding robotics.

Disclaimer: I’ve been in competitive Vex teams for three years so I might be a bit biased, but have also had experience with Lego Mindstorms kits.

I can’t add much to what has been said already. I started playing with robotics several years ago building much smaller robots from scratch, and I mean everything. Laser cut acrylic for the chassis. Custom designed microprocessor and sensor boards, programming completely from scratch. It’s takes a lot of time and for me the fun was in the creation, as soon as they were finished I moved on to another one. I only found VEX about a year ago as my Son became involved at high school and it really is a lot of fun working with the students.

If you want to look smaller kits Pololu and Robot Marketplace also have them.

I would say that if you invest in VEX and then change your mind later on, recouping most of your investment on the more expensive items will be possible. The cortex I would think would be easy to sell on eBay, they almost never come up for sale.

Edit. One other thing, if you are near to a high school with a team, I’m sure they would be happy to show you their work and perhaps recruit you as a mentor later on when you have caught the bug :slight_smile:

I’ve worked intensively with LEGO with students (9 years) and Vex (6 years) so these are the systems I know best. I’ve glanced over a number of other systems, and none has “caught my eye” as being better than either of these systems for the purposes I want (cheap but reasonably challenging vs. extremely challenging). Whether you choose LEGO or Vex depends on a number of things:

  1. What is your price range? (LEGO NXT starter including simple software is < $300, Vex Classroom Lab kit plus software is $850+$75). For a “fun” kit, I don’t recommend anything less than the Classroom Lab kit. See the Kit Purchase section in this document for more details on recommendations for Vex kit purchase or here for LEGO kit purchase.

  2. How good is your ability to reverse engineer, i.e., look at a single photo and build it to a functional level, rather than using a sequence of step-by-step pictures? About 10% of the 100+ (admittedly, many lower income) students I’ve worked with (including talented programmers) can reverse engineer from the start. An additional 20% gain the ability to do so after 2-3 years of working on a team. But 100% of my students (even the least gifted) are able to build from step-by-step instructions from day one. LEGO NXT has many projects with step-by-step instructions (commercially available books, and free website). The only Vex projects with step-by-step instructions I know about are 2 projects on the official website, and 15 projects in this document. However, there are thousands of photos on the Vex forum, if you can reverse engineer.

  3. How much time do you want to spend on the mechanics? For a simple Vex project with step-by-step instructions, I’d estimate a minimum of 2 hours to build. For more complex projects, the sky’s the limit. Our team typically spends 50-100 hours building a competition robot (a minimum of 10 per subsystem, i.e. 10 on lift only, 10 on grabber only, etc). We have programmers who love to program,but typically only get 2-5 hours with the robot the whole season, because we run out of time before a competition. With your own kit and no time limit, you won’t have this problem. However, to make a Vex robot do what you “really want” (including many projects on the Vex forum), it’s likely that you’ll need to cut metal, increasing the time and cost involved. Simple LEGO subsystems can easily be built in 1/2 hour, and many complex projects can be built in 2-3 hours.

My personal recommendation for most people who have never done robotics before is to start with a LEGO NXT kit. Have fun with it, build supplemental projects from nxtprograms.com. When you get bored with it, save your pennies and move on to the Vex Classroom Lab kit. The main limitations with LEGO are not variety – it has a decent variety of sensors (touch, light, ultrasonic, & sound sensors, and motors have built-in rotation sensors). The biggest limits I’ve found are strength and quantity (only 3 motor ports, 4 sensor ports, vs. Vex’s 10 motor ports and 16 sensor ports). If you want to lift more than a few ounces, LEGO doesn’t cut it, while Vex robots can easily lift 5 lb. or more. If you want to perform more than 3 tasks at a time on the same robot, Vex is the system of choice. But if you want to try out one idea at a time, disassembling and reassembling between projects, LEGO is fine. Vex parts are also reusable, and even cut metal is usually not wasted, as many projects use pieces of similar size.

Although LEGO NXT already comes with simple software, since you’re already programmers, you might consider purchasing ROBOTC for NXT; however, if you want ROBOTC for Vex, you would need to repurchase it separately.

Enjoy!

Is VEX for Me? That is a good question…

Many others here at the Vex Forum have posted their suggestions… I will try to not duplicate them…

First… If you want to do a little more research as to your options, there are some Magazines dedicated to Hobbyist Robotics and Hobbyist Electronics…

The one that I subscribe to are:
Servo Magazine
Robot Magazine

also
Nut and Volts Magazine
Elektor Magazine
Make Magazine ( Issue 27 focuses on Robotics )

there is also available:
Circuit Cellar Magazine

and others I am not aware of…

The Robotics based magazines will have Advertisements for many of the above mention Robotic focused business, plus a few others not mentioned…

Some Robotics Systems are “cute”, like the Sony Abio, some are “Violent”, like the Battle Bots, and almost all are “educational”. You will need to see what you are looking for in a Robot… :wink:

How much time you want to spend assembling the Parts and Pieces and How much time you want to spend working with your Robot is the Deciding Factor. When I first saw Vex, I thought, “It looks like an Erector Set, with a Programmable Microcontroller… How COOL is THAT!!”.

What you are getting for your Money with a Vex Robotics System is:
[LIST]
*]Parts Engineered to Work together.
Electronics protected from incidental damage.
Modular Building System, for all sub systems.
Starter Documentation.
ALL of US, here at the Vex Forum.
and of course, The component parts themselves.
[/LIST]

The “total” is more expensive that just buying the individual parts and pieces from other Vendors, but with Vex you are also buying the Engineering Expertise, the pre-made assemblies and support and sympathies from knowledgeable Vex Users.

I have a Vex biases too, since I bought most of my Vex systems back in 2006, when Radio-Shack was discounting them to 50% - 33% of the list price… So I got into Vex at a lower cost than some people, but I have not regretted it, because I have spent more time working on making working Robots than assembling the Pieces to make a working Robot… Vex’s were designed for Competition, so there is an emphases on Achieving a Goal, Working a Plan, Solving a Problem…

Vex does have a Claw that can be purchased, too…

Having worked in the Embedded Programing industry for 10 years now, I have many chances to work with different Microprocessors and Compilers, as well as Off The Shelf and Proprietary Hardware systems. I have used just about all my skills developed with Embedded Programming on the Vex Robots. Compared to the Lego NXT, they are more Robust (more Metal Chassis Parts), more Motors and Sensors, and ( I think )more “flexible” in Programming. There are other Robotics Kits, but they seem to be focused on teaching the basics of Robotic, rather than actually attempting to accomplish a goal.

I also will note that I have help Mentor a Vex Team one year in the USFIRST First Tech Challenge (FTC), an FRC Team for three years for USFIRST First Robotics Challenge (FRC), and competed in an Underwater Remote Operated Vehicle Challenge in the MATE Competition.
FTC uses the Engineered Vex Parts, but FRC and MATE you piece together all the systems to complete your “robot”

As mentioned by jpearman, if you apply your Mechanical Experience and your Wife’s Programming Experience to Robotics, there are many Middle and High School teams that need Professional Mentors… Use the Team Locator at USFIRST or VEX Robotic to locate a Team near you, and contact the Lead Mentor… Even if you would just be interested in learning more about Robotics…