pic: 1067's robot (almost done)

Ok, to point out a few of the finer points in the design. You can see that the front-right leg of the quad-pod is finished with the grinder, see my other pic for a description.

As you can see, 4-wheel drive with 12" wheels. the front wheels are polyurethane, but they were too small and after much tearing of hair, one of our guys decided to drill 7/8" holes in them and pound 1" marbles into said holes. As pictured, its a bumpy ride, but rest assured that the marble count has increased by lots, so its smooth enoung and slides around on turning quite well.

The main feature of this picture is the arm. It has two stages, with the first stage rotating around the top of our robot. Fully extended straight up its about 13' or so. Not on the arm as of now is the claw, which will fold to meet size restricitions, but will not be articulated (other than opening and closeing) once it is extended. We had the arm up and running yesterday. It was pretty incredible. The entire arm will rotate turret-style.

You may also be able to make out the winch. It is a winch.

You can see our electronics board mounted near-verticle behind the arm.

The window motors may or may not power our fold out wings which may or may not be on the finished robot.

I think thats a pretty good summary.

Well, there she is.

Questions, just post em here.

First question answered today is: Why yes, those are marbles in the front wheels.

And a close up of our finish (only on that right leg as of now)

Again, questions/comments welcome. Yes, everything that is connected works, so far.

marbles are glass right??? and a 130lbs robot slamming into a diamond plate 6in wall at (i dunno how fast you guys are, but say) 6ft/sec. is that marble still intact?
and how did you get those marbles to stay in the hole? apoxy?

Yes, they are glass. And yes, perhaps they are breakable, but we have driven this thing on concrete at 8’/second with no breaks.

We realize it might be a problem, thats why we didn’t glue them in (we haven’t had ny fall out, either) so we can replace them easily.

we also drop the marbles alot, on concrete, with no problems.

Come to think of it, I’ve never ever seen a marble break. A sphere is a pretty strong shape.

BUt we might break one or two during competition. Thats what spares are for.

oh they break alright. in middle school, i once tried to beltsand a marble into a shape of a cube. the sander did grind quite a bit of the marble away before the marble literally exploded. yes. it was pretty scary. thankfully no teachers were watching. no harm done, but i learned my lesson. still don’t know exactly WHY it exploded, but it did.
that doesn’t prove if marbles will break on impact but if i were the judges, i might say that it is a hazard in the field because IF it breaks, it can be sharp.
i’d check with FIRST if i were you.
i’m also looking for a way to help us turn easier. i’m not sure zip ties are the best way either. if anyone thinks up an idea, please contact us or post it somewhere.thanks!

ANother idea is to buy flooring epoxy (have you ever seen an epoxy floor – I have one in my house, its good stuff) and cover the kit pneumatic wheels with it and let them harden. Then you have (basically) wheels with epoxy treads, plenty slick enough for you.

two questions- is it top heavy at all, and how long does it take you guys to get your arm up to the bar?

looks pretty slick- nice job

The whole thing pictured weighs in at 90-110 lbs, somewhere in that range.

The CG is low enough that we can drive it around all crazy like and not flip (although I could make it do wheelies before we dropped the arm in).

if we get our wheels on another robot and keep driving we could go over. We can do the little stairs no problem, and if we can et up the 6 in step we have talked abour using the arm as a counterbalance to keep it from going over.

We can get that arm straight up in a few seconds. Maybe a bit longer to do the precision adjustments nescessary to get the hook on the bar.

Ok, some updates (and a shameless bump, though I do hate double-posting)

We have a sprocket drilled out to fit our turret shaft. The big (3") hole visible in the motor plate is for a FP motor, and the sprocket will fit inside the robot on the big pole, and be driven by the FP motor. thus we can turn our arm around and around. More difficult to build, but it should be awesome to have the driver park the both and let the arm operator do his thing, without all the inefficiencies that happen in less-thatn-perectly trained teams.

Driving is becoming harder with the arm, but it is still much faster and handels much better than our 2003 robot. It requires experience, though. The dedicated freshman can tip it over while driving, although all of us were putting it through a stress test and he is the only one who almost made it flip. Inexperienced as he was, he reacted fast enough to save it. Maybe he has potential as a driver, but not this year. If it goes over without something else causing it, its our driver’s fault. Hopefully we will get one smart enough to know whats what. Turning with the marbles is great, although we may look into non-glass replacements. Its gotta be something with balls, though, its just too funny of an idea. Back to the point of this paragraph: as of now the controls for the arm aren’t finished, so the arm is unpowered when we drive. Therefore it has a tendency to flop around some, especially the rotating (turret) part of is which is not connected to a motor, so if the driver makes the wrong move, the arm freewheels around the robot. No major problems, but its something we are keeping an eye on.

The claw is marching steadily towards completetiong (especially because we still have 9 days till ship!) and I don’t think there will be a problem with that, but then I did design it and I am building it, so I may not be that objective. Everything works so far.

I hope to get some more time with that hand-grinder soon and do that finish. Its ridiculously cool. I hung that one sample peice from the ceiling of our room with a few zip-ties. Its our substitute for art. Or maybe its our art. Maybe.

Well, theres the update. Hopefully more pics tommorow. Anyone know where I can host ~5meg divX files, I took some of them and would like to show them off.