Re: Enough buying talk. Let's hear about ghettofab!
 

I have participated in at least two ghettofabs during my 3 years. The first one was 2002.

There was one advisor who insisted on having four, crab-movable and lifting up tank treads, which weighed in at 50 pounds. This only left room for one arm, and we could only haul one goal with all that power. We didn't do well at all that year, and instead of going to nationals (the last time they were held in Orlando :( ) , we went to the St. Louis Regional. There the other advisors and upperclassmen decided to remove two of the tank treads and replace them with the equivalent of aluminum casters. That gave us weight (about 20 pounds) to put the arm back on and we decided we would have to have a mechanism that goes back to the home zone (to score 10 points). We didn't know what to do until an advisor suggested measuring tape. So we put a roll of measuring tape on the top of the robot and had a FP motor shoot it backwards to the home zone. It worked quite well, and was made completely out of wood, completely on site without any machine shop.

This year (2004), our arm wasn't working with the high standards we hoped it would. Even when the pneumatic was pushed all the way in, the ball would still slip out. I suggested supergrip (which we used extensively last year) but it turned out we didn't have any. Then somebody suggested using a popped 2x ball to do the trick. We got a popped 2x ball (I don't remember whether it was form our kit or from our good friends on 447) , cut it into strips, and stretched it around the arms. We then used Zip Ties (Confucius' Law of FIRST: Know thy Ziptie :D ) to keep it on, and the only times a ball went out of the arm after that was when it was vigorously pushed out. Proof that Ghettofab works.

Re: Enough buying talk. Let's hear about ghettofab!
 

zip ties...

We originally had used this nice piece of getofab to hold our wench line up against the arm, and when it was time hang those things would go flying, but by the end of the build we had replace them with some medical tube and hooks which would actually stay intact and on the robot.

Re: Enough buying talk. Let's hear about ghettofab!
 

This year 45 had a lot of "ghetto" stuff on it I think. Such as our pool floatie toy pads on the sides and rear. To our front gate we put on at nats that myself and Andy built in like 30 minutes. It was just lexan riveted on to a aluminum tube. It may have been ghetto by my terms but it was also P.I.M.P. HAHA! :rolleyes:

-Kyle :]

Re: Enough buying talk. Let's hear about ghettofab!
 

In the spirit of Dave's comments, I very much believe in the plastic trash can lid also. Our robot this year had an arm with suction. The suction cup: A wal-mart trash can lid with non-porrous foam contact glued to form a seal. To power it: A FP on a shop vac impeller. Other ghettofab parts. Thighmaster roller-pad to supposedly keep from running over the ball. Xerox machine parts used 4, coupler for different motors. To keep the winch from unraveling, a piece of plastic was put around the lead screw. Never came unraveled.

For last year: Edurobot wheels used to form grippers on arm. Held on with plastic automotive push-screws. Caster wheels for turning: We use go kart racing tires on both years robots and can make turning hard. When we had the two extra days we decide to put pneumatically actuated casters on the back to help turning. After plasma cutting a spot while everything is on the robot we fit the caster wheels that saved us from numerous tips into place.

Robovation ghettofab: I took the robovation bot to college with me for an open house booth. I realized the tiny tires weren't going to cut it so I saw that I had both foam board and electrical tape. Using the old hubs, foam board and electrical tape I made new wheels which worked great. More foamboard, duct tape, a three ring binder v piece: I build a protective shell with a scoop, side flaps, and a pusher on back with a duct tape hinge. Three ring binder and IFI parts, Gravis gamepad, velcro and 222 battery: Carryable Controls(all fit in the binder).

Re: Enough buying talk. Let's hear about ghettofab!
 

125's ghettofabulous moment happened in Annaplois. We used 4 8" pneumatic tires to provide great traction. Unfortunately, we had such traction that turning was almost impossible. To remedy the situation we decided to shave the tread off the wheel.
In the pits we put the robot on blocks and put a student with a file at each wheel. Pretending to drive forward we used the motors power to help shave down each tire. Unfortunately, we had limited success and rubber particles everywhere. You thought the smell of blown motors was bad, the burnt rubber was much worse.

Re: Enough buying talk. Let's hear about ghettofab!
 

On 1405, we had originally decided to use Fischer price motors to run
our winch. We started fabricating a mount, which consisted of 1/4"
aluminum plate with a big hole for the output of the gearbox.

After starting the mounts, and cutting out the holes (using a parent's
hole cutter attached to the drill press), the students saw 340's robot
which used a van door motor for their winch. They decided they'd
rather do that. The circles of aluminum that the hole cutter left were
lying beside the drill press when we realized they were the perfect
size to use at the end of the shaft.


You can see the circle just on the far side of the van door motor in the middle.

Re: Enough buying talk. Let's hear about ghettofab!
 

we broke a sprocket in half during competetion and welded it back together.

one of our rubber "grippers" in the 2003 game broke, so we zip tied some orange grippy safety gloves we had onto it.

our robot was made out of wood and pvc, now i think that just is the definition of ghetto.

Re: Enough buying talk. Let's hear about ghettofab!
 

Well, our robot looked the most ghetto at the 2004 Great Lakes Regional. The numbers were electrical tape, and the thin Lexan we used was already ripping and coming off. Our robot was originally four wheel drive and 80 percent finished when it was shipped off, so everything was hastily put together at the competition and we ended up with a two wheel drive robot, as it couldn't turn well. The front two wheels were replaced by casters. To add to all of this, we had to remove around 5-10 lbs (I think). Our drills were almost burned out after all the swiss-cheeseing that had to be done. By the end of our first day, the robot still wasn't done. This is mostly due to the fact that our robot was built in about two weeks, with our back door system designed and built in the last week :ahh:

I don't have many ghettofab details from competitions though, as I was mostly in the pits bugging...I mean...scouting...other teams.

Re: Enough buying talk. Let's hear about ghettofab!
 

in 2003, we used a t-shirt to protect our electronics.

in 2004 at the canadian regional, we weren't able to turn with our pneumatic tires, so we put 2 castors on, but then it became too easy to overturn, so we decided to put some kind of plastic skids. well we spent an hour looking for some and nobody had any nylon or delrin. Later on that night our teacher was out at canadian tire and noticed...a cutting board. So he bought it. The next day we went in with out cutting board and cut 4 pieces out of it and bolted it to our robot


and to quote one of the members from 783 . "now normally, you cut things on the cutting board, and not the cutting board itself"

Re: Enough ghettofab talk, lets hear about ghetto-rules...
 

Does anyone understand why the "tape cannot be used as a fastener" rule applies to team numbers and other signes on their robot? me neither. This rule was the source of team 8's ghettofab entry (unless you count our entire robot...) just this last year 2004. San jose regionals roll around, and shortly after uncrating our robot and performing some minor pre-planned maintanance we went to get a judge for qualification. Electronics check, pneumatics check, team numbers... not high enough

no problem says i

4 8.5x11 sheets of paper, masking tape and a lot of sharpie later, we are ready to call back the judge.

electronics check, pneumatics check, no tape as fasteners... not so check.

our ghettofab solution, was to zip tie the blinking sheets of paper to the verts on our robot... not only ghettofab, but weaker than what was illiegal... someone tell me why this makes sense???

Re: Enough buying talk. Let's hear about ghettofab!
 

we used a 1/4" bolt as a cotter pin for our arms primary joint ("Its a quarter inch of hardened steel . . . it'll hold!").

We sheared that mug twice.

I think we broke every cotter pin in the arm at least once. It was nuts.

Haha, best ghettofab, though.

So we used 4 wheel tank drive, two drill motors, right? Not enough power to skid with 4x 12" pneumatic skyway wheels. So we used two pneumatic wheels in back, two hard rubber in front, but the hard rubber tires were a lesser diameter, and stilll too sticky anyway. So we went ghetto omniwheel: we drilled .9" holes around the outside of the hard rubber tires and super-glued 1" marbles into them. It worked great. And it set us apart. Good stuff.

Re: Enough buying talk. Let's hear about ghettofab!
 

You got to take a look at 1212. This year we won the Arizona regional. We had cardboard numbers, metal light shade, and a hose for the vacum. Just take a look at this.

Re: Enough buying talk. Let's hear about ghettofab!
 

I have to agree with Matt we DEFINATELY have the ghettoist (is that a word?) robot around, just take a look at it, we have the ugliest robot in the world and yet we somehow won the arizona regional and got 22nd in Newton division at nats.

Re: Enough buying talk. Let's hear about ghettofab!
 

We had the same issue with the turning last year. After taking off the front wheels we tried spinning castors from our car. That made it turn too fast, so we went with the back non-spinning castors off the same cart. This was again to hard to turn.
The solution: We put both. 4 sets of castors on the front. 2 spinning, 2 fix. It averaged out and worked great.

Re: Enough buying talk. Let's hear about ghettofab!
 

I would say that 814's 2003 robot, Spicy Mustard, was 100% ghetto-fabulous.
Spicy was wooden. Very wooden. The chassis was made of 3/8" plywood, the arm pieces were made out of 1/8" plywood epoxies to high-density foam. The "lobster" claw was made the same. In order to make Spicy pretty, we used wood stain to give him some color, and covered the bumpers with this really UGLY upholstery.

We had a limit button that made the elbow motor stop once it was hit. But the top came off of the button and we didn't have time to replace it. So we bought one of those gardening knee pads, cut out a chunk of it and ziptied it to the section of the arm that hit the button.

Needless to say, Spicy is the most successful robot the team has ever made. We won Judge's Choice and Leadership in Controls, and were regional finalists.