12-03-2012 12:33

JABot67

Re: pic: Heroes of Tomorrow 2012 - HOTBot

Thought I might start a discussion on this. This thing is a beast. An absolute beast. I wish there was more video of it working so everyone could see how easy it is to balance the Coopertition bridge or triple balance when this robot is a factor.

Congrats for winning Waterford, HOT! You will go very very far this year with your completely unique robot. I could almost compare the advantage that this bridge utility arm gives to the advantage that 469 gave an alliance in 2010. Almost....

12-03-2012 12:34

nikeairmancurry

Re: pic: Heroes of Tomorrow 2012 - HOTBot

Adam can you post pictures of how the arm collects the balls and how they are held in the arm?

12-03-2012 12:38

Re: pic: Heroes of Tomorrow 2012 - HOTBot

This robot is one of the best things I've seen in my time in FIRST. Not only is thing a scoring BEAST, but it is also THE best bridge bot in Rebound Rumble. The CG is so low, that if this thing tips, I might as well disassemble our entire robot, because if 67 tips over wit this bot, we'll tip over with ours.

Beautiful machine 67! It's teams like HOT that inspire FIRSTers to make quality robots and innovate amazing designs like this one.

12-03-2012 12:40

Jeff Rodriguez

Re: pic: Heroes of Tomorrow 2012 - HOTBot

I am really interested to know how well that arm holds up throughout the competition season.
Did it take any hard impacts from other robots? What is it designed to take?
Also, what spares have you planned for it?

Very cool design.

12-03-2012 12:48

Chexposito

Re: pic: Heroes of Tomorrow 2012 - HOTBot

I would also like to see how you guys did this. Great robot as usual.

12-03-2012 13:21

Adam Freeman

Re: pic: Heroes of Tomorrow 2012 - HOTBot

Nick,

The best I can do right now is link to our website photo album. There are a couple of good pictures that I think will show how the intake system works.

http://frcteam67.dyndns.org/HOTPhotoAlbum/index.html

Basically, it's similar to how teams picked up balls in 2010. The front roller grabs the ball and pulls it into the lower bar and the rear roller. This picks the ball off the ground, so we can continue to move around and collect balls. The rear roller is un-covered PVC which allows it to spin on the ball when the ball hits against the bumper. Both rollers are connected by round belting and are spun with a 550s (which also power the wheels on the arm).

The wheels are there for traversing the barrier and pushing up the ramp, if needed.

The arm rests on the gas struts that assist the motors and have been designed to have the wheels ride about 1/2" above the ground during normal operation.

When we lift the arm to dump into the hopper, the ball is pinched between the lower bar and the rear roller. This hold the balls until we spin the rollers to drop the ball into the hopper.

PM me if you want more detailed pictures, I can send you some screen shots of the design.

12-03-2012 13:57

Adam Freeman

Re: pic: Heroes of Tomorrow 2012 - HOTBot

Jeff,

I also am interested to see how it holds up to abuse. I think it was designed pretty robust. Our process is more experience based guessing, than hard calculations. We had 2"x3" tubing ordered...it seemed like 2"x2" might not be enough...so we went with the bigger tubing.

The entire arm mounting is tied into the frame structure. The arm pivot is 2" diameter 1/16" wall tubing.

Since the entire arm and pivot are welded together, we have one spare arm which is fully assembled on our practice bot. We also have spares of all the attachment pieces and rollers components in case those become damaged.

The plan would be to attempt to repair the arm as much as possible if it gets bent up. If not, pull it off and replace it with the practice bot arm.

We didn't take any big hits at Waterford. Short of running it full speed into something, I am not that worried about it getting serverly damaged. The arm was designed to protect the rollers from taking an impact, with (2)-2" AL angle pieces placed in front of them....so, I feel ok with them being safe.

When the arm was initially welded, it flexed and ended up outside the 14" limit. We attempted to bend it back, with a chain, some huge pieces of steel, and some 200+lb engineers. After flexing over 3/4"...there was a huge "pop" and we broke the right elbow arm weld joint. We re-clamped the arm into the right position and re-welded it. We may gusset that joint, if matches start getting crazy.

Thanks for all the great comments!