31-05-2011 22:36

MattC9

Re: pic: Gruff

It looks like a BEAST. Where are yall going to compete with it, and in what competition?

31-05-2011 22:38

AdamHeard

Re: pic: Gruff

They competed at robogames 2011.

Just seeing it in a match with that tread, I knew it had to be someone FIRST related.

31-05-2011 22:41

slijin

Re: pic: Gruff

Are those 4" wide wheels? And... a tank roller in the center?

Good god. How does that thing turn?

31-05-2011 23:14

Re: pic: Gruff

Any videos of it in action?

31-05-2011 23:30

SamM

Re: pic: Gruff

6" wide wheels...But with 1/8" effective drop on the center wheels. We had 1/16" drop for the previous competition and had problems until later in the competition when the floor was coated with a thin layer of dirt and debris.

The tread in the middle is actually just a bumper I taped on during testing to keep the lifting arm from banging up our own frame too badly when it rotates back.



I am a Team 79 alumnus and mentor. I designed and built Gruff as part of an Undergraduate Honors Thesis project at USF and now compete in competitions with the USF Robotics Interest Group.

31-05-2011 23:38

SamM

Re: pic: Gruff

Vs Sewer Snake, Repeat winner of Robogames. This is the fight that was televised.

http://www.youtube.com/watch?v=WqL6auwhztE
http://www.youtube.com/watch?v=D0JDCFcYliw

Vs Double Rainbow Party, a shell spinner.

http://science.discovery.com/videos/...-vs-gruff.html

I have some more videos from Robogames that I'll try to get up.

01-06-2011 00:01

legogeek24

Re: pic: Gruff

That first fight has to be one of the most epic robot battles I've ever seen! Both robots were awesome!

01-06-2011 01:10

Akash Rastogi

Re: pic: Gruff

Man building something like yours or Sewer Snake would be such an awesome offseason project. About how many man hours did you put into your machine?

Sick matches.

01-06-2011 12:16

Borntolose

Re: pic: Gruff

What kind of control system does that thing use?
Awesome matches, by the way, looks like a fun project.

01-06-2011 12:18

M. Mellott

Re: pic: Gruff

If anyone's interested, the show (Killer Robots: Robogames 2011) is airing tonight at 10pm and 1am on the Science Channel. 60 minutes of robot mayhem!

01-06-2011 12:22

legogeek24

Re: pic: Gruff

If only I got the Science Channel!

01-06-2011 12:38

SamM

Re: pic: Gruff

It's hard to estimate the number of hours that went into it, but it is no more complicated than your average FIRST robot.

I'm using a 2004 IFI control system which has held up well so far (I've heard their weak point is the DB9 cables going bad. 98% of the other teams use a 2.4Ghz RC Airplane or Car system.

01-06-2011 13:38

torihoelscher

Re: pic: Gruff

How long did it take you to program?

Sorry programming questions! lol

01-06-2011 13:40

torihoelscher

Re: pic: Gruff

This is awesome. I didnt even see the team number.....whoops! Hello fellow Krunch!

Congrats! PSN sent out an email about this a couple days ago. Congrats!!!!!

01-06-2011 13:42

techtiger1

Re: pic: Gruff

I feel like this should be on display somewhere at TNT in September. I know people would be thrilled to get a close up look at a robot like gruff assuming its still together. Finally, it would be a nice addition to the event attractions.

01-06-2011 15:08

P. Fuller

Re: pic: Gruff

About how much did this cost to build?

01-06-2011 18:56

Thermal

Re: pic: Gruff

Along on that note, how heavy is this bot, and did you still use just a single 12v battery or did you add one or two more in parallel?

01-06-2011 23:41

SamM

Re: pic: Gruff

Hi Tori,

It's actually only running a slightly modified version of the 2004 Default Code.
I've added deadzones to the joystick centers to keep the bot from drifting, and added a feedback system that measures current draw and motor temp. This is relayed back to the driver by shaking the joysticks with the intensity of vibration proportional to the current draw, and a heating coil on the joystick matches the joystick temperature to the motor temperature. Programming isn't exactly my specialty, but it took me about a week to make these modifications.


I've got about 4k of my own money invested in Gruff. The University, and the Robotics Group's Sponsor, Southern Manufacturing Technologies have helped with shipping and travel.

It competes in the 220lb, Heavyweight Class. For power at the past two competitions I've been running two 12v 17Ah batteries in series for 24V. They were Enersys Odyssey PC625 Models. Motor setup is kind of strange in that one Victor 885 controls two CIMs in series so each only sees about 12V. The 24V choice was made because it's cheaper, smaller, and easier than running twice as many at 12V.

This setup will last little more than 3:00 minutes of hard driving, which means if the weapon is used much, I had to be very careful. For this reason we'll be testing some Lithium Polymer batteries this summer (Twice the capacity with 1/2 the weight).