We call him Brutus-I. We created him just so we could get a feel for creating a real FIRST robot. This guy took us about a month of 2-day a week sessions to build.
http://www.forsythalliance.com/Pictures/05_12_13%20Week%2019%20Kelly%20and%20Joan/p1010015.jpg
http://www.forsythalliance.com/Pictures/05_12_13%20Week%2019%20Kelly%20and%20Joan/p1010016.jpg
So how is this thing for a Rookie Team robot?
That looks GREAT! Remember to use the KISS principal during the real build season and you will do great!
Wow!
I must say that looks really good. That was good thinking on your part, making a practice robot before the season to see what it’s like.
My only question, did you buy all the parts, or did other veteran FRC teams donate theirs?
Great job guys.
Wow, that is really well done, and only one month at 2 days per week to build! I would love to have our team that motivated this year.
I also would like some feedback on your drive train. That is almost identical to what I have been envisioning for one of our future (near future I hope) designs. My belief is that it would be highly maneuverable and fairly responsive. Is that what you are finding? Also, do the casters cause any problems or are there any other drawbacks you have been experiencing?
To Ryan Foley,
We bought the build kit that used for last year’s FIRST competition
to billbo911,
The maneuverability is very well done and responsiveness is top-notch according to our trial runs and such. As for drawbacks, it tends to veer to the left if driven straight forward
A simple design always gets the job done right! Excellent machine and best of luck this year! 
WOW that is a cool robot. good job if you guys did that in that small amount of time im scared if my team has to go against yours.
Scared of a rookie team? :rolleyes:
Oooh boy, you’ll learn quickly. The only thing vet. teams have going for 'em is reliability. And generally not even that. The rookies are the ones who say for example:
Hmmmmm…if we jump off the 5’ ramp with a load of game pieces at 10 ft/sec, we can get to the goal really quickly…
And the “too crazy for us, we know better” schemes always seem to work! You guys will have loads of fun. 
wow that looks great, good job. How much does it weigh? looks like you used 80/20 profile
It weighs a little over the maximum standards for FIRST robots, about 140 lbs and true, we did use 80/20
lol no… but we have lost to rookie teams in the past, for some reason I cannot see the picture of the robot, you may want to upload it to the image gallery here at CD.
edit: I can see it now, looks good. I would not recomend a 2 wheel drive at all, at least try for 4 wheel drive .
80/20 does have a bit of heft to it, but I’m sure you could knock off some pounds. (Those wheels appear to have some heft, at least from the photos.)
Do you plan on using 80/20 for the chassis, or use whatever we get for the kitbot frame this season? The Kitbot frame is pretty good at what it does.
Either way, good stuff! The first robot you build is the one where you actually figure out what you’re doing, so it’s always a good thing to have that one not count. ((http://www.chiefdelphi.com/media/photos/33740))
We tried a 4 wheel drive in our kitbot, not that one, and it was very difficult to get bot to do a gradual turn to the left or right while moving forward. We eventually took those off and use giant ball-bearing wheels in the final design of our kitbot. We used the same ball-bearing wheels on Brutus, but in the front and back while we used the drive-wheels in the middle.
What size 80/20 did you use? It looks like the 1.5" x 1.5" 80/20 was used for everything. You can use the 1" x 1" 80/20 for most of the chassis frame to help save weight. If you want to try to cut back on the weight of the robot, here are a few helpful ideas:
There are a lot of “extra” 80/20 pieces on the robot that you might be able to take off if other joints are strengthened. Also, if you have the machining facilities used to mill the holes for the 80/20 corner joints, you might be able to machine pillow blocks for the axles out of regular aluminum stock rather than 80/20, as it may save you a bit of weight. On some of the 80/20 members on the frame, they overlap another piece. You can knock off a few inches of the 80/20 (and knock off a bit more weight) by having all the joints be “butt joints” that join together in the same plane (rather than skewed joints).
Otherwise, this looks very nice for a robot built in a month, let alone by a rookie team. You guys should do well this year.
Looks great guys. and Kyle is definitely right, K.I.S.S. all the way. As for the problem of the bot veering to the left slightly, from what I can tell you have you axle mounts mounted directly to the 80-20. You may want to check that your 2 drive wheels are spaced exactly the same position on the chassis for both sides, if they aren’t that may be what is causing your problem.
JT
229
Yes check on the spacing. When we used the 80/20 back in 2001 for our robot we had to check them every so often because they loved to slide on us. Also be careful with the 2 wheel drive robot, especially if you get into a pushing match with a team since yours could possible spin easier than one that is 4 wheel.
Also there I haven’t searched through the White Papers on drive trains or other mechanisms lately so I’m not completely up to date on what they have. But i do know that if you are interested in researching drive trains there are a few helpful pieces that JVN wrote up on our teams website. One of them is here:
http://team229.org/resources/single/181
Good luck to you guys in the up coming season. Hope to see you guys doing well at the regional(s) you attend. Remember to K.I.S.S. and you guys will do fine.
Looks like you have a very good start Snappel!
Concerning the drive train, you may want to be aware of whether or not your drive train meets the demands of the game. What you have here is great for a game that requires maneuverability and good offense (such as this past years’ game), but I would not recommend this setup (2 wheel drive with casters) for a game that was highly defensive and required your robot to push another robot or drive up an inclined surface (any veteran teams out there remember the “caster-bots” of 2003 and how they would often veer off to the side while trying to get up the ramp?)
The same principles that make 2 wheel drive robots extremely maneuverable are the same ones that make them easy to push around. If this coming year’s game requires alot of defense (bots pushing other bots), I would not recommend going with this setup. Instead, I would go with a 4 wheel drive setup instead.
Perhaps you know this already, but by altering what is called the “track” and the “wheel base” of a four wheel drive robot, you can achieve different degrees of maneuverability. Here is a paint sketch illustrating this:
http://i6.photobucket.com/albums/y237/jaine716/bot.jpg
Perhaps the first time you tried building a 4 wheel drive, your track was too short in comparison to your wheel base. You can try adjusting the ratio of track to wheel base until you find a perfect balance between maneuverability and pushing ability. I would recommend this setup for dealing with inclined surfaces (such as ramps), as well as defensive ones, so that your robot won’t have difficulty climbing them.
Of course, there are alternatives to this design. You could go with a six wheel drive robot, with its middle wheel slightly lower than the rest, which would give it both a high degree of maneuverability as well as pushing power. Or you could try omni wheels, swerve drive, mecanum wheels… etc. However, the 4 wheel drive design is the simplest available in comparison to the others… and as rookies, it is best for you to stick with simple designs that you can master before progressing to the next level of complexity in design. I believe someone has already said it, but I will say it again: K. I. S. S. (Keep It Simple Silly)! Oftentimes, the simplest ideas are the best ones.
Good luck,
– Jaine
BurningQuestion has a lot of great information. The bottom line is that simple 4WD skid steering has to overcome the friction of the wheels to slide them sideways. Thinner wheels, omni wheels, shorter wheelbase vs track are all ways to reduce the effect of the wheels skiding sideways. Engineering is all about compromise and designing for the task that the competition presents.
Looks like you guys are of to a great start.
“Rookie” just means you are new to the game, not that your team isn’t as skilled as many already in the competition.
Last years final rookie team in FRC, 1708 from McKeesport, PA, was a Regional Champion at Pittsburgh. You may be surprised at how well your team does this year, but most veterans won’t. We’ve seen talented rookies come in every year and play at very high levels of competition.
Good luck, and enjoy your season!