Re: stairs
 

How about using spokes to push the robot up to the stair

Re: stairs
 

just thought
-rather than a caster, which will get caught on the stair, go to a semi sphere or similar delrin or teflon material, make it so it wont get cought on the angle of the stair

we're still working on a drive system for the stairs, but think about having 4wd in the rear or front, and a delrin piece in the back,make the front or back wheel in the 4wd pivot so it can "climb" the stair
this is going to be an amusing attempt, but i have no pics and cant post them even if it did
pcture this on both sides

--------------
| |
| |
| wheel |
| | make the system pivot on one wheel on both sides
--------------
| |
| wheel |
| |
| |
--------------
edit: ok it looks good in the reply page, but on the thread the spaces are all messed up

Re: stairs
 

Spokes? you mean like something to grab the edge of the stair and pull it up...what if your, lets say, wheels where big enough and had sort of a toothed tread and it could easily grab and hold an edge and work its way up...giving you had clearence, and everything else needed...multiple wheels, 4 wheel drive...

Re: stairs
 

the spoke would work but look at robot specs R13, you'd have to be really careful about the technicalities of that one

Re: stairs
 

If anyone remembers our 2001 bot, it had an arm with a range of motion close to 180 degrees and a rotating wrist at the end of it. Meaning that, when positioned the right way, the arm could lift the front two wheels off of the ground. I wish I had a picture of us doing this, but if you look in the CD galleries you should be able to get an idea of what I'm talking about. Although it hasn't been tested, I'm sure that it would be able to lift the front wheels enough to get up the step. Then it could rotate the arm 180 degrees to lift the back wheels up enough to get up the step. This would only be possible with a bot with 4 wheel drive though.

Re: stairs
 

This is also what Team 60 did with their arm in 2001 to cross the midfield barrier.

Re: stairs
 

threads and wheels are good idea.... how about think a little outside the box.. why not add a mechanism which will help you to get on the platform... ;)

Re: stairs
 

the easy way would be to just to litterally fly. but barring gas fuel or nuclear fusion I'm thinking that might be a little advanced for most teams.... otherwise I think my team figured it our you'll need almost a 16-18 inch wheel to get over the "bump" and that's provided you end up with something like 10 inch casters or you can stick to the tried and true methods of tank drive and offset wheels (one higher and the rest normal.) your real worry should be about flipping (cringes at thought of Icarus last year) :rolleyes:

Re: stairs
 

did you consider that you might not have to get up on the plaform, or that you may not want to.

I assume you are trying to go for the chin up, so consider this:
The edge of the platform is only 2 feet from the bar. so as you approach the bar, whatever you are going to use to hoist yourself up is going to have to go starit up. If it is a lifting arm or some sort, you can basically add 6" to 1' onto the arm and reach the bar without getting onto the platform

well thats my idea at least

Re: stairs
 

interesting. you think that an arm or something that long could fit within the starting dimentions? If it has many pivots for folding I fear that it wont be strong enough to life a 130 pound bot

Re: stairs
 

In 2001 we built a 14ft. teloscoping arm on our machine so that we could put a big ball on a goal while it was balanced on the bridge. But that was our only mechanism besides the drive system because we designed it so that it could also manipulate the goals. So I wouldn't advise devoting so much weight to such a long arm if all that you are going to do with it is hang.

Re: stairs
 

you could easily use that arm to get a 2x ball... and plowing the balls to the coral doesnt really take any special parts (if you dont mind doing it inefficiently)

Re: stairs
 

Yea, that is how our team seems to be leaning as far as how to get the balls, hang, and pick em up....Another thing with the arm, if the center of gravity is rather low, you could use the arm to push down on the step, causing the bot to lift, and roll yourself onto it....I think.....dunno... :rolleyes:

Re: stairs
 

Well currently, my team is tweaking our design to get up onto the platform. Basically we figured you just need to have enough ground clearance and the wheels spaced rightly, and with enough momentum you should have no problem getting up. Our only problem now is our frame is getting caught up on the platform, which should be fixed by tommorow hopefully. I'd really hate to be a rookie this year :rolleyes: