26-04-2003 21:26

camtunkpa

lol

Looks like you had a bit of a weight issue, I see lot's of speed holes Nice idea for proto.

27-04-2003 18:35

Specialagentjim

hehe, yeah, we had quite a few of those jokes throughout class...

...then of course came the idea that the parts lego gave us weren't good enough, and we wanted to cut them to make them work right :-P

27-04-2003 18:45

Frank(Aflak)

heh, I built an omni directional drive base using the RIS. I took those wheels you used, deprived them of tires, and then spent hours and hours searching through all my blocks for all the little peices I needed to turn them into omni wheels.

Its of the thre-wheeled variety . . . . I've yet to perfect the program. Its ugly as hell, but it works beutifully.

I used the mid-sized pulleys to get the wheels to be 60 degrtees apart . . . . maybe I'll post pics sometime.

27-04-2003 19:25

Ryan Dognaux

You made lego omni wheels?! awesome! Post pictures sometime if you can.. I'd love to see that!

27-04-2003 21:16

Andy Grady

Legos!!

On a serious note, Lego's are a great way to do Mock-Ups of robots during the build stage. That right there would put across an idea for a robot in an amazing manner. Good job!

-Andy Grady

28-04-2003 22:45

Specialagentjim

Except for the problem that occurs when trying to coordinate real physics with "lego" physics- A totally seperate entity from physics in whcih things that shouldn't work do, and things that should work don't. WHy this is the way it is, we don't know, but after a few weeks of builidng these things for class, we've learned it the hard way once again. lol

29-04-2003 00:04

Jnadke

He's not really referring to omniwheels, but the Killough drive platform. It's a 3-wheeled drive that can be assembled in any number of ways. It basically looks kinda like a peace sign or a Y. Usually, you'd use omniwheels and the wheels are perpendicular to the ends of the Y, so that 2 wheels would drive the robot and the third would follow (slide across the floor).

http://dec1.wi-inf.uni-essen.de/~ast...C2000/s_9.html

29-04-2003 17:43

Ryan Dognaux

Woa that is awesome.. I'd love to see that in lego-form.

29-04-2003 21:38

Frank(Aflak)

thats it. But I had to make omni wheels first.


I was going to make four omni wheels and put em 90 degrees apart (much easier) but I couldn't find the pieces for the fourth (as it is I barely finished three) and the RCX and my control pad only have three outputs.

I haven't programmed it yet, because I need to find something that will let me program the RCX using trig. I know I heard of a more powerful program some techie made for programming it, but I haven't found it yet ( i haven't looked that hard either).


It is ugly, but it works. It works well, too, I was surprised. I need to find 18 little tires to make it work better though. God, I hate searching for little pieces. Pics sometime. Maybe now. I'll see. gotta motivate, and stuff.

Edit: Okay, i motivated myself. Pics are pending mod approval (i don't THINK there is anything obscene in there) and are in the 2003 robot gallery (or will be soon).

I think it was fun. I really am a big nerd. But thats why I built robots.


about the drive base . . . . if you drive the wheels at different speeds you can have it go in any direction, and with more complex math (hence my need for a trig programming language for the RCX) you can have it go in any direction and rotate at the same time while following a straight line. It really is too cool. We plan to do something like it next year but with four wheels instead of three.

30-04-2003 20:30

Carlo

OMNI WHEELS???

Lego omni wheels, now that my friend deserves a High Five.
That is awesome

30-04-2003 21:36

Frank(Aflak)

the pics are up. Four of em, really high res ( I used an EOS-1D).

I would put up videos, somewhere, but I don't have anything with which to shoot digital videos.

such a shame. I think I named my pic poorly, no one seems to have noticed the thread.