Robo-Cross B

[koustubh24]

Does Anyone Recommend Having 2 Motors For A Crane/Claw And Also 2 Motors For Wheels With One Claw Attached To The Front Just Used To Push Things Or Should I Get Rid Of The Claw In The Front To Push Things?

[Flavorflav]

SO me and my partner have been getting perfect scores (like 98% of the time), but when we ran at our regional competition, the border between Zone C and D fell off (they hot glued it) and we got about 100 points. They let us go again at the end of the day, but then our left wheels got pinched. We still got 2nd though (we got a score of 159), so I'm pretty happy.

I have to say, I was worried about my field at our regional last Saturday. One of the teams had a plow and couldn't get over the 1/4 round, so they kept backing up and ramming it over and over. It was screwed and glued, though, and the screws held fine. Not so much the glue - it popped free and was flexing in the middle something fierce because I only screwed it on the ends, but it held. I would recommend three screws to anyone building a competition field.

Top score was about 126 after incomplete documentation penalty. One of the potentially best bots tipped over and another overheated its motors, so a lot of disappointed kids.

[jander14indoor]

What kind of glue and did it break in the glue, or wood split off?

Jeff Anderson
Livonia, MI

[Flavorflav]

It was CA and it does appear to have been the glue that failed, but it probably wasn't completely cured. I'm a high school coach myself and I hadn't really visualized the event properly. I imagined robots rolling over the barrier rather than trying to bump over it, so at first it was just the two screws. I saw some flex on the first bot which happened to be the only bot that hour, so I added the CA that morning. It had almost an hour to set and didn't show any flex for the next eight or ten bots, but it couldn't take the repetitive ramming. It was PVC to MDF, BTW - I could not find any wood 1/4 round in the required size range.

[hscmom]

What kind of glue and did it break in the glue, or wood split off?

Jeff Anderson
Livonia, MI

At Southern Colorado Regionals it was simply hot glued. And, after the break, hot glued again. The robot that knocked the piece lose was a perfectly legal and had Vex parts.

[jander14indoor]

Sounds like time for Gorilla Glue.

CA is strong but brittle, even with good cure it is likely to crack from that kind of shock loading.

Hot melt, absorbs shock, but has to be applied right for a REALLY good joint. Not something I'd want to use mid-tournament for repairs.

Thanks for the warning though!

Jeff Anderson
Livonia, MI

[UQOnyx]

For practice, we are just using duct tape for the barriers. The robot just climbs over..
NEW QUESTION:
This is pretty important. When measuring the robot, does it have to be turned on, or can it be off?

[UQOnyx]

(bump)
Read post above.

[Flavorflav]

I always measure them off, but I'm afraid you are asking that question because your robot gets larger when you turn it on. If that is the case, then I think you are going to have trouble. It needs to fit in the space in the ready-to-run configuration, IIRC.

[jander14indoor]

Unofficial, opinion, ask on the national site for official answer, etc.

Ready to run seems to imply being on. And this year it explicitly says it must fit an imaginary box so you can't depend on the measurement method holding it in shape or to size.

Jeff Anderson
Livonia, MI