Arduino?

[Kusha]

Well, I'm a sophomore and a month back I bought my first arduino after reading up about it at 2am since I couldn't sleep.

I've been designing a robot that would be a 3 motor 3 omni wheel, kiwi drive in cad.

My question is, is this a good starting point for me? I've played around with it with some old dc motors I took out of some CD drives. Learned how transistors and capacitors work. I'm currently looking for a good bluetooth module to attempt to get the robot I'm building controlled via android. Along with 3 good motors, some omniwheels and a ultrasonic sensor that will be mounted on an servo.


Am I putting too much on my plate, or is this a good goal and a good starting place for me?

[davidthefat]

I would say that it is a great project. I say go for it, what do you have to lose? Even if you "fail", you would have learned so much along the way.

[Kusha]

Originally Posted by davidthefat

I would say that it is a great project. I say go for it, what do you have to lose? Even if you "fail", you would have learned so much along the way.

You're right. But I just didn't want to get on a project that would
A) Never get done
B) Fail because I lacked the skills needed to finish the project.

But you're right, so far just experimenting with leds and motors and such has given me so much experience.

I guess the next step is to find some motors.

[EricH]

CD drive motors aren't good motors? News to me. Gear 'em right and they'll be pretty darn good. (Trust me on this. ONE CD drive motor geared down a little bit can get a 52-second time over a 20' course. That was at about 1/3 speed.)

I think a kiwi drive is a decent option for some offseason programming. It's a challenge, but there is some code around, I think, that can help you figure out
what you need to know.

[Kusha]

Originally Posted by EricH

CD drive motors aren't good motors? News to me. Gear 'em right and they'll be pretty darn good. (Trust me on this. ONE CD drive motor geared down a little bit can get a 52-second time over a 20' course. That was at about 1/3 speed.)

I think a kiwi drive is a decent option for some offseason programming. It's a challenge, but there is some code around, I think, that can help you figure out
what you need to know.

It doesn't seem to me that I can drive the design I want with cd motors.
I was planning to get some time with our mill and mill some plexi out in the form of two circles, one on top of each other and everything else wedged inside of there like a sandwich.

PLUS, I wouldn't know where to start with gearring a cd motor .

If I can find some good motors on amazon and get them shipped with prime, I could have an amazing weekend ahead of me. Besides the fact that there is a robotics meeting this weekend.

[EricH]

I'm not certain how it was done, but a small R/C type gearbox had the motor directly attached to it. I *think* the ratio was 16:1. Wheel on the output shaft. This was the extension/retraction motor, BTW. If I had to guess, the pulley was removed from the motor and a gear put on. You might also be able to pulley into the gearbox.

For a kiwi drive, you might want to consider a triangular base instead of a circular one.

As another option, go with VEX. Those motors look like small servos. It's also possible to use continuous-rotation servos.

[Kusha]

Originally Posted by EricH

I'm not certain how it was done, but a small R/C type gearbox had the motor directly attached to it. I *think* the ratio was 16:1. Wheel on the output shaft. This was the extension/retraction motor, BTW. If I had to guess, the pulley was removed from the motor and a gear put on. You might also be able to pulley into the gearbox.

For a kiwi drive, you might want to consider a triangular base instead of a circular one.

As another option, go with VEX. Those motors look like small servos. It's also possible to use continuous-rotation servos.

I was thinking about a triangular base with arms on each corner
each arm holds a motor, or I can just go with a regular triangle, I haven't made my mind up yet about the complete design.

Vex motors? Got a link?

And I have NO idea what you mean by continuous-rotation servos.

I'm still a newbie, this is how I want to get even MORE involved in robotics in general.

EDIT:
Are these the ones you're talking about:
http://www.vexrobotics.com/products/.../276-2181.html

Would they be powerful enough to do what I need them to do?


I'm going to sleep. Tomorrow I'll update with pictures of my cad designing. Hopefully Saturday I'll have some freshly milled parts ready and possibly some motors waiting for me to play with.

[EricH]

We'll start with the easy stuff.

Continuous-rotation servos: Servos are motors that will go to a given position and do their best to stay there. However, some folks make continuous-rotation versions, which look the same but rotate continuously.

Go with a regular triangle; the mechanical work will probably be easier. Also, look in CD-Media for some pictures of kiwi drives.

VEX motors: The VEX website is http://www.vexrobotics.com/; motors are under the "motion" category. Also note the omniwheels and other miscellaneous items...

Edit: Yep, those or their cousins in the same line.

[Kusha]

Originally Posted by EricH

We'll start with the easy stuff.

Continuous-rotation servos: Servos are motors that will go to a given position and do their best to stay there. However, some folks make continuous-rotation versions, which look the same but rotate continuously.

Go with a regular triangle; the mechanical work will probably be easier. Also, look in CD-Media for some pictures of kiwi drives.

VEX motors: The VEX website is http://www.vexrobotics.com/; motors are under the "motion" category. Also note the omniwheels and other miscellaneous items...

Edit: Yep, those or their cousins in the same line.

Ok, thanks for the help how about I update this thread tomorrow once I have some time thinking about the design and to see what you think?

[sanddrag]

It'll never work. I think you should just pack up all the hardware and send it to me for proper disposal. I'll send you a box with a prepaid label to put it in.

All jokes aside, it sounds like a great project. Be sure to post back letting us know how it goes.

[DonRotolo]

If you hit a roadblock - something that stops your progress - I advise taking whatever that subsystem is, and just default to some other solution that you know you can implement but is less than "ideal". Get it working with the lesser solution, and eventually you'll find a way to implement a better solution.

In other words: When you stall, default to "anything that'll work" until later.

Good luck, ask questions when you need to.

[Kusha]

Small update here. I've been really busy with AP tests. On Saturday after GEAR (my mentors' lego competition) (I'm refing there.) I'll be going out to goodwill and some thrift stores to see if I can find some old rc cars so I can harvest the motors.

I finally made v3 of my base. I know I haven't showed v2 at all but here's v3.



It needs some adjustments but I like the concept. I also have some handdrawn stuff too, but I'm too lazy to upload. I'll be documenting and keeping everything. I seem to be getting the hang of inventor. This project is awesome so far.

I've also been playing around with some variations with the cold cathode, I think I have away of powering it it fully, I just need to find a good 12v power source....

PS.. This is what my folder looks like http://i.imgur.com/i4pM3.png I have been working on it. Slowly but surely. Now that AP tests are over for me I'll start to speed things up

Suggestions on design?

[ProgrammerJoe]

Provided you already have an Android phone, you might want to look into Google's new ADK as a method of programming, where you can physically hook the phone up to the board like a tether, or integrate it into the system itself. They say they have Bluetooth support coming soon as well, and if not, you can also use Amarino. Just food for thought.

[Kusha]

Originally Posted by ProgrammerJoe

Provided you already have an Android phone, you might want to look into Google's new ADK as a method of programming, where you can physically hook the phone up to the board like a tether, or integrate it into the system itself. They say they have Bluetooth support coming soon as well, and if not, you can also use Amarino. Just food for thought.

I don't want to pay 300bucks for the ADK. I'm going with Amarino. It's a bit outta my price range seeing as I'm going to thrift stores just to get old RC cars.

The adk is great and all, but no thanks.

Thanks for the suggestion tho

[Kusha]

http://cgi.ebay.com/Omniwheel-transw...ht_1081wt_1139

Are these good enough omniwheels? Or is there any better/cheaper ones I can buy?