When you get into a small, cheap, complex 6-axis arm, the weight of each servo/link/joint becomes significant and reduces the payload, and increases the whole moving mass. Counterspringing helps, but not perfectly. Unless you want to spend lots of money on beefy metal gear servos, keep the parts light. I'm not a LEGO expert, but I suspect a custom designed & built arm for your needs might be better than what they have. My 6-axis arm was as lightweight as possible, servos glued to servos, and thinwall aluminum for the arm links.
I hope you don't let other people tell you how to spend your money?
If you do, then don't buy either. Send your money to me.
Lego makes good stuff, you can learn a lot with it. You'll eventually (if you like making robots) use material that's stronger than Lego.
It sounds like you want to buy a NXT no matter what we say (which is fine); the NXT might be good choice if it will motivate you to learn about robotics.
Maybe, depends on you. If you have previous NXT experience & equity, then probably, as you'll get up to speed faster. A lot of smart people like Mindstorms, but I have not tried them. I like Philo's stuff, and he's into Mindstorms: http://www.philohome.com/index.htm
Someone more conversant with NXT should chime in with recommendations if the other comments here aren't enough for you to decide. I'm in the minority, I like doing everything the hard way, from scratch. Reinventing the wheel my way.
Much depends on how comfy you are with mechanical fabrication. THAT is the heart of robotics IMHO. Scratch building, not limiting yourself to what is already built (or what can be built with LEGO/VEX or erector sets).
I didn't want to miss a chance to disagree with erco. (Though technically I'm not disagreeing, because I agree that what he said is his opinion. So I guess I'm just expression an alternate opinion.)
In my (I wont claim it's humble) opinion the heart of robotics is programming. Even if one never were to build their own robot, they could be a great roboticist if they can come up with useful algorithms.
As I often hear (and say) "hardware is easy, software is hard." I think you can learn a lot about robotics from programming the Scribbler 2 robot.
I have many good robots that could be great if I could only program them to be so.
I did not think you were being rude. Any how, like others have stated, it is YOUR decision. If you want to learn from the ground up and really have a fun experience I would go with the less expensive Parallax products. There are so many things you can do whether it be with robotics or not. The learning experience IMHO is worth every penny (dollar(s)) that I have spent on their items. However, if you simply want to build a robotic arm that plays chess or checkers and then be done with it then the NXT may be the way to go. I just feel that there is so much more that can be learned and accomplished using Parallax products.
Well knowing that it is possible to build a chess playing robot from scratch(using parallax components) makes me wonder if I should go the lego or the parallax way. I know that the lego way is probably easier but I dont have the money to buy the kit. I can afford the boebot and whats a microcontroller kit however...
Anyone in here read the Robot Builder's Bonanza? Im getting some ideas from it. Maybe I dont have to spend the extra money for the NXT 2.0.......
As Erco mentioned, Gordon reads this forum and checks in from time to time. I've done several threads over in the robot forum inspired by projects from RBB and have another one in progress right now.
I have and have read most of RBB. (I skimmed parts I thought I already knew.) It's a great book to learn about building robots. I wish it had been available when I first started out with robots.
I think this review at Amazon illustrates some of the short commings of the NXT kit. There are also many positive reviews.
I'm a huge Lego fan. I have hundreds of thousands of Lego bricks. Every so often I think I'll build a robot out of Lego but I get frustrated at how easily they come apart (I don't glue my Lego). It's so much easier to use some plywood or Aluminum "L" channel or "C" channel to quickly make a robot structure.
There are tricks to get a Lego structure to be stronger but these tricks also make taking apart the structure very difficult. I use some Lego pieces in many of my robots. I buy some of the Lego pieces I use (gears and turntables) from BrickLink so I don't take pieces from complete sets (many of my older sets are valuable to collectors).
About four and a half years ago I decided I finally wanted to learn how to use microcontrollers. After reading several hobby electronics and robot magazines I decided to try Parallax products since they had so many books and tutorials on how to use their stuff. I had read that the Propeller was more powerful but the Basic Stamp 2 was easier to use. So I purchased both. I got a BS2 BOE-Bot and a Propeller Protoboard and Prop Plug.
The BS2 BOE-Bot was a lot of fun. Parallax's text made it easy to make a light avoiding robot and by changing a couple of zeros to ones in the code the light avoiding robot became a light seeking robot. This was very cool.
Once I started learning to use the Propeller, I saw I didn't have much use for the BS2 anymore. Propellers are much less expensive and much more powerful than the BS2.
I helped a little with the programming of BS2 project to celebrate the Queen of England's 60th Jubilee. This project played "God Save the Queen" with a small piezo speaker and waved a cardboard hand. It was a lot of fun to see the video. The problem was, the BS2 couldn't do both actions at the same time. It had to wait until the song finished before waving the hand and it had to stop waving the hand in order to start playing the song. A Propeller can control multiple servos, play music communicate serially and do other stuff, all at the same time.
Now when I read those same electronics and robot magazines, I often think "they should have used a Propeller" as an author mentions how they had to leave some feature out of the project since adding the feature messed up the program's timing caused the servos to jitter.
I think I can see some advantage to using the BS2 first but, in my case, I don't think it was worth the price. I think I would have been better off using the money I spent on Stamps to buy other robot stuff.
I just have to say I think you made the right choice choosing the boe-bot/whats a micro controller. It may take you a bit longer to get where you want as far as a robotic arm playing chess but it will give you the tools and confidence to build your own from scratch or it may even make you realize there are alot of other things you want to do with robotics. When I first got involved in electronics/micro controllers a year ago I had no intrest in building a robot what so ever, then I found some old erector sets and figured id try my hand at a robot as a side project, using the stuff in the erector sets. Flash a few months forward the robot has become my main project, its still using erector stuff but only for SOME of its structural stuff ive been lurking on surplus sites waiting for the best deals. Building a robot like this has taken alot of time and research though, after 2 or three months im just now building a motor controller and battery charging system.
The reason I wasnt in to robots so much is becuase I thought like you why do I want some stupid thing that rolls around, or even what would I use a robotic arm for.... After alot of experimentation and realizing just how much you learn from robotics ive definitely changed that point of view. I have two ultimate goals and putting them on a robot or rolling autonmys platform just makes them even cooler. My first one is to use a wii-mote cam to make a #D image scanner basically you sweep an object with lasers and determine what it is youve just scanned by turning it into a 3d model. The second and even more ambitious project is acually a free MIT class online. I want to go through MITs coureware to build a radar system that has about a mile of range and can collect enough data to make hi resalution images of whatever its bouncing off of. The idea is to eventually have the robot climb the mountain behind my house and beam radar at the town, wirelessly transmitting the data to my PC below. The wiicam scanner will be used to scan rocks and other obsticales on the mountain so the robot can make better path finding desicions. MY only point is rolling platforms give way to new ideas that may be much more exciting than where you orginally intended to be
Welp due to money issues I will do the Boe bot and what s a Microcontroller thing and also read Robot Builders Bonanza and see if I can build a chess or checkers playing robot. I will study websites
and see what I can do! Years ago when I was like 13 years old I built a 5 foot tall robot made of foam . It was pretty cool I used a toy truck for the locomotion of the base of the robot.
I got this book called Maximum Lego NXT. It s definitely going to take more than one NXT 2.0 set to make the chess robot Im thinking about. It would probably be better to buy a cheap arm robot and connect it to the BASIC stamp microcontroller!
After your familar with the basic stamp if you decide to make a chess playing robot using the basic stamp to control the arm and the PC to do the acuall chess calculations I would suggest using something like this
It will allow you to send simple serial communications wirelessly from your computer to the bs2, after reading whats a micro controller you should be fairly familiar with how one would get this working
A chess or checkers playing bot is quite a task for your first run. If you are talking about building the arm and controlling the moves yourself that will not be too difficult. However, if you want it to play on it's own that is going to be a bit more difficult. Good luck and keep us posted on how it goes. I am sure you will get all the help you need from the experts here.
I thought someone had made a Propeller vs Human chess game. I found it. Rayman (he makes lots of cool stuff) made a Chess game that's displayed on a VGA monitor.
Rayman's chess game could take care of the chess calculations needed by the robot arm.
If you want to use a camera with your arm to figure out where the chess pieces are, you could use on of the Propeller machine vision options (listed in post #4 of my index).
Actually I did notice like people have said , in this forum, that the Parallax products are cheaper than the LEGO parts.
Not only that. If you hang out here long enough, they will give you one of everything FREE. Contests, giveaways, "first ten people to do X", etc. I'm still worried that Ken and Matt are giving away the farm!
Ya dude, Erco is right! Ive been having financial difficultys for a while, that's all about to change though going back to work building a solar plan soon! Anyways This is why I do everything from scratch including building my first propeller board, also the more DIY you get with electronics the more you can do with no money, most chip companys give samples. Anyways after I built a prop board or two I nded up winning a QuickStart from Jeffs sight, PropellerPowered.com and then a Whats a MicroController kit from parallax with an optical finger module. If your savy you can do electronics for very cheap, the only thing I usually spend money on is components like crystals, caps and resistors. Once every few months I drop a 100 or two on a bunch of dev boards etc but most of the time I can salvage or sample or even WIN!
I do like the Dynamixel servos. They are powerful and have all sorts of cool features, but they are expensive.
I purchased a bunch of AX-12+ servos (newer version is the AX-12A, older version is the AX-12) and a CrustCrawler Smart Arm.
Ratronic wrote a program to control a Smart Arm with a Propeller. I modified his program to use a RC radio as the input device. I was fun but not very practical.
The Smart arm is probably strong enough to lift and move chess pieces but I'm sure there are less expensive options to accomplish this task. I had purchased my Smart Arm in hopes of using it to automate some of the work I do in my chemistry lab so it was tax deductible.
If I were to try to make an inexpensive robot arm strong enough to lift chess pieces, I'd probably use servos from HobbyKing. I list some of the HobbyKing servos I like in post #10 of my index. The HX12K are really strong for the price. I'd probably double up the servos on some of the joints like the Smart Arm does. The Vigor VS-11 is stronger (and larger) than the HX12K servos. I purchased some of these based on erco recommendation. I haven't used them much yet myself. The Vigor VS-11 servos could be used on a joint near the base of the arm if I thought the "shoulder" joint needed more power than the HX12K servos provide. I'd probably use aluminum "L" or "C" channel from the hardware store to make the structure of the arm. HobbyKing sells square carbon fiber (CF) tubing that would also work well for the arm structure. I used this square CF for the arms of my hexacopter.
I'm pretty sure one could make a DIY robot arm as strong as the Smart Arm for a small fraction of the price of the Smart Arm. I'd probably be tempted to use AX-12 servo(s) on the gripper since the AX-12 servos let you set the torque used by the servo. The AX-12 servos also will report the amount of torque it is experiencing which allows some level of force feedback when using the servos.
Comments
Duane likes those fancy Dynamixel servos. I haven't tried 'em myself, but they have a great repulation and they're cheaper in bulk, here are six for $225 : http://www.trossenrobotics.com/dynamixel-ax-12-robot-actuator.aspx
That's completely up to you.
I hope you don't let other people tell you how to spend your money?
If you do, then don't buy either. Send your money to me.
Lego makes good stuff, you can learn a lot with it. You'll eventually (if you like making robots) use material that's stronger than Lego.
It sounds like you want to buy a NXT no matter what we say (which is fine); the NXT might be good choice if it will motivate you to learn about robotics.
Someone more conversant with NXT should chime in with recommendations if the other comments here aren't enough for you to decide. I'm in the minority, I like doing everything the hard way, from scratch. Reinventing the wheel my way.
I didn't want to miss a chance to disagree with erco. (Though technically I'm not disagreeing, because I agree that what he said is his opinion. So I guess I'm just expression an alternate opinion.)
In my (I wont claim it's humble) opinion the heart of robotics is programming. Even if one never were to build their own robot, they could be a great roboticist if they can come up with useful algorithms.
As I often hear (and say) "hardware is easy, software is hard." I think you can learn a lot about robotics from programming the Scribbler 2 robot.
I have many good robots that could be great if I could only program them to be so.
As Erco mentioned, Gordon reads this forum and checks in from time to time. I've done several threads over in the robot forum inspired by projects from RBB and have another one in progress right now.
I have and have read most of RBB. (I skimmed parts I thought I already knew.) It's a great book to learn about building robots. I wish it had been available when I first started out with robots.
I think this review at Amazon illustrates some of the short commings of the NXT kit. There are also many positive reviews.
I'm a huge Lego fan. I have hundreds of thousands of Lego bricks. Every so often I think I'll build a robot out of Lego but I get frustrated at how easily they come apart (I don't glue my Lego). It's so much easier to use some plywood or Aluminum "L" channel or "C" channel to quickly make a robot structure.
There are tricks to get a Lego structure to be stronger but these tricks also make taking apart the structure very difficult. I use some Lego pieces in many of my robots. I buy some of the Lego pieces I use (gears and turntables) from BrickLink so I don't take pieces from complete sets (many of my older sets are valuable to collectors).
About four and a half years ago I decided I finally wanted to learn how to use microcontrollers. After reading several hobby electronics and robot magazines I decided to try Parallax products since they had so many books and tutorials on how to use their stuff. I had read that the Propeller was more powerful but the Basic Stamp 2 was easier to use. So I purchased both. I got a BS2 BOE-Bot and a Propeller Protoboard and Prop Plug.
The BS2 BOE-Bot was a lot of fun. Parallax's text made it easy to make a light avoiding robot and by changing a couple of zeros to ones in the code the light avoiding robot became a light seeking robot. This was very cool.
Once I started learning to use the Propeller, I saw I didn't have much use for the BS2 anymore. Propellers are much less expensive and much more powerful than the BS2.
I helped a little with the programming of BS2 project to celebrate the Queen of England's 60th Jubilee. This project played "God Save the Queen" with a small piezo speaker and waved a cardboard hand. It was a lot of fun to see the video. The problem was, the BS2 couldn't do both actions at the same time. It had to wait until the song finished before waving the hand and it had to stop waving the hand in order to start playing the song. A Propeller can control multiple servos, play music communicate serially and do other stuff, all at the same time.
Now when I read those same electronics and robot magazines, I often think "they should have used a Propeller" as an author mentions how they had to leave some feature out of the project since adding the feature messed up the program's timing caused the servos to jitter.
I think I can see some advantage to using the BS2 first but, in my case, I don't think it was worth the price. I think I would have been better off using the money I spent on Stamps to buy other robot stuff.
The reason I wasnt in to robots so much is becuase I thought like you why do I want some stupid thing that rolls around, or even what would I use a robotic arm for.... After alot of experimentation and realizing just how much you learn from robotics ive definitely changed that point of view. I have two ultimate goals and putting them on a robot or rolling autonmys platform just makes them even cooler. My first one is to use a wii-mote cam to make a #D image scanner basically you sweep an object with lasers and determine what it is youve just scanned by turning it into a 3d model. The second and even more ambitious project is acually a free MIT class online. I want to go through MITs coureware to build a radar system that has about a mile of range and can collect enough data to make hi resalution images of whatever its bouncing off of. The idea is to eventually have the robot climb the mountain behind my house and beam radar at the town, wirelessly transmitting the data to my PC below. The wiicam scanner will be used to scan rocks and other obsticales on the mountain so the robot can make better path finding desicions. MY only point is rolling platforms give way to new ideas that may be much more exciting than where you orginally intended to be
and see what I can do! Years ago when I was like 13 years old I built a 5 foot tall robot made of foam . It was pretty cool I used a toy truck for the locomotion of the base of the robot.
Do you plan to have the robot interface with a PC to perform the chess computations?
I'm pretty sure the Basic Stamp 2 can't play chess on its own.
I think chess would be tough for the Prop, but I think I remember someone making a chess program for the Prop.
http://www.ebay.com/itm/HC-05-Bluetooth-Transceiver-Host-Slave-Master-Module-Wireless-Serial-6pin-/221151793361?pt=LH_DefaultDomain_0&hash=item337dac90d1
It will allow you to send simple serial communications wirelessly from your computer to the bs2, after reading whats a micro controller you should be fairly familiar with how one would get this working
I thought someone had made a Propeller vs Human chess game. I found it. Rayman (he makes lots of cool stuff) made a Chess game that's displayed on a VGA monitor.
Rayman's chess game could take care of the chess calculations needed by the robot arm.
If you want to use a camera with your arm to figure out where the chess pieces are, you could use on of the Propeller machine vision options (listed in post #4 of my index).
Not only that. If you hang out here long enough, they will give you one of everything FREE. Contests, giveaways, "first ten people to do X", etc. I'm still worried that Ken and Matt are giving away the farm!
I do like the Dynamixel servos. They are powerful and have all sorts of cool features, but they are expensive.
I purchased a bunch of AX-12+ servos (newer version is the AX-12A, older version is the AX-12) and a CrustCrawler Smart Arm.
Ratronic wrote a program to control a Smart Arm with a Propeller. I modified his program to use a RC radio as the input device. I was fun but not very practical.
The Smart arm is probably strong enough to lift and move chess pieces but I'm sure there are less expensive options to accomplish this task. I had purchased my Smart Arm in hopes of using it to automate some of the work I do in my chemistry lab so it was tax deductible.
If I were to try to make an inexpensive robot arm strong enough to lift chess pieces, I'd probably use servos from HobbyKing. I list some of the HobbyKing servos I like in post #10 of my index. The HX12K are really strong for the price. I'd probably double up the servos on some of the joints like the Smart Arm does. The Vigor VS-11 is stronger (and larger) than the HX12K servos. I purchased some of these based on erco recommendation. I haven't used them much yet myself. The Vigor VS-11 servos could be used on a joint near the base of the arm if I thought the "shoulder" joint needed more power than the HX12K servos provide. I'd probably use aluminum "L" or "C" channel from the hardware store to make the structure of the arm. HobbyKing sells square carbon fiber (CF) tubing that would also work well for the arm structure. I used this square CF for the arms of my hexacopter.
I'm pretty sure one could make a DIY robot arm as strong as the Smart Arm for a small fraction of the price of the Smart Arm. I'd probably be tempted to use AX-12 servo(s) on the gripper since the AX-12 servos let you set the torque used by the servo. The AX-12 servos also will report the amount of torque it is experiencing which allows some level of force feedback when using the servos.