Robotics Platform

medelman

I need some advice. I'm looking for a robotic base. I don't have a machine shop to build anything complex, so if possible I would like to purchase a kit or parts to build one. I've seen several ones that are running into the thousands and I don't have that kind of money. Most likely I will be running a propeller chip along with two HB motor controllers. I've thought about purchasing an iRobot create and attach a propeller to that, but I was kind of interested in something that could go off a flat surface. Ultimately a platform that could also support a light weight laptop (4 pounds) and GPS for navigation/location would be great. Can I build something like this on my own without spending a fortune? Slightly off topic, but I'm living in Mountain View, CA (Far away from the midwest) for the summer doing an internship and I was wondering if there are any GEEKY places I can't be sure to miss? I plan on going to the Computer history museum around the corner. Any places that have some good robotics?

Matt

DiablodeMorte

I can't help you with the geeky places(If you were in florida maybe) but I can suggest a robotics platform. Right now i'm working on 2 robotics platforms, The first is quite large and sounds like what you want. I used a Powerwheels(those huge toy trucks kids sit in a ride around). They are huge and can be controlled w/ two HB-25's. They already have electric motors and all that needs to be made is an aparatus for turning the front wheels. The second platform i'm working on uses a rather large rc racing truck chassis. It is built for off road but is way too small for a computer, if/when i put one in it will probably be a gumstick w/ linux.


-My 2 cents.

Tom C

medelman,

You might take a look at this link if you change your mind about the Create/Propellor combination: http://www.wulfden.org/create/wac1.shtml
Just a thought.

Regards,
TCIII

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If you are going to send·a Robot·to save the world, you·better make sure it likes it the way it is!

Post Edited (Tom C) : 6/18/2007 7:23:15 PM GMT

Kevin Wood

You might want to just spend some time walking around a Home Depot or Tractor Supply store. You'll find all kinds of stuff that can be built into a robot.

medelman

Thanks the replies,

I have thought about the RC Truck kit in the past as well. They definitely would have the maneuverability that I'm looking for. I have seen people that have used R/C tanks, but they seemed to have problems themselves. What RC chassis are you using? A power wheels would be cool, but I don't really have the room to store it.

Kevin,

My problem with building my own, as much as I want to, is trying to match up gears with wheels and what not. I am not mechanically inclined I guess.

Matt

jfizer

A little costly, but this seems like a good starting place for a platform.

http://robotstore.com/store/product.asp?pid=782&catid=1552

Tom C

jfizer,

Your link is to a Lynxmotion 4WD2 which you can buy directly from Lynxmotion: http://www.lynxmotion.com/Category.aspx?CategoryID=58

You might want to try the 4WD1, which I have, which is cheaper by about $40: http://www.lynxmotion.com/Category.aspx?CategoryID=57

Anything that you buy from Jim Frye at Lynxmotion is going to be a quality product.

Regards,
TCIII

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If you are going to send·a Robot·to save the world, you·better make sure it likes it the way it is!

jfizer

Tom C said...
Your link is to a Lynxmotion 4WD2 which you can buy directly from Lynxmotion:

That it is. I kinda like the one I linked over the basic once because the two halves can swivle giving it somthing akin to suspension.

jcolonias

·

Hi,

I am using an RC tank platform which I hacked very easily. I have removed the RC receiver, I added an H-bridge from (http://geocities.com/jimforkin2003) which incidentally is excellent.

Now, am in the process of adding sensors for the turret rotation, gun position, obstacle avoidance, etc. If you want I could email you some preliminary pictures that I took.

I have had very little trouble thus far.

John

Dgswaner

take a look at http://www.thinkbotics.com/ I'm not suggesting that you should buy one of these books and build it, but that is an option.. I'm suggesting that you look at the construction of the bots they build. with a hack saw, drill and a little imagination you could build a robot chassis to suit your every need. All of the aluminum that they use is readily available at home depot.

I've built sever bots out of plexi and Lexan. it's a really inexpensive medium. Most Plastics suppliers will cut pieces to order. even round and with holes.

this post talks about other building materials.
http://forums.parallax.com/forums/default.aspx?f=10&m=189280&g=189405#m189405

I think you'll be much happier building your own chassis, and putting more money into sensors.

Good luck

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A complex design is the sign of an inferior designer. - Jamie Hyneman, Myth Buster

rokicki

Well, it depends on what you're trying to do, of course.

But even the cheap RC models have differentials on the rear, proper steering
(that is, the inner tire turns at a tighter angle), usually four-wheel independent
suspension, and plenty of speed. Most of all, though, the mechanicals are really
built to take a beating; a few of the cheap RC cars I've bought have been crashed
a *lot* (slamming directly into curbs at full speed) and they never seem to break.

On the other hand, they still look and function like R/C cars. For instance,
they won't pivot in place like most standard two-wheel robots will. They really
aren't designed for adding any significant additional weight. They frequently
do not have a convenient place to attach sensors or additional electronics.
And frequently they are *too* fast, and hard to throttle down (even the
digital proportional models need some sort of sensors to monitor the speed;
just varying the pulse widths may give you a stall on some terrain while
giving you substantial speed on other terrain.)

A lot depends on what you are good at. I stink at the mechanicals, really really
have no talent there, but I can program, so I like kits and slightly modified
R/C cars that I can just attach a microcontroller and sensors to. But the
amazing robots people build from "scratch" always impress me.

Rocketmaniac

I have started building my robot with 80/20 aluminum stock. I've gotten all of my pieces from the following ebay seller (this is a side business of the main company that sells seconds and returns at a discount price)

http://stores.ebay.com/8020-Inc-Garage-Sale_W0QQssPageNameZstrkQ3amefsQ3amesstQQtZkm

I used the 1010 stock which is 1" X 1". After I built the frame I found that they had some 1050 stock that was 1" X .5". I would use that if I were to rebuild the frame. I'll post some pictures of the frame and how I connected it all together if anyone would like to see what I've done.