Enough buying talk. Let's hear about ghettofab!
 

Alright, so while the buying stuff debate rages on, I'm going to create a refuge.

Let's hear about your (either your or your team's) greatest moments at the art of ghettofab. Let's hear about your electrical tape team numbers and cobbled-together parts and transmissions that miraculously worked in competition!

It's time to celebrate the ugly, the how's-that-hold-together, the "I need a tetanus shot looking at it" creations!

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

at the peachtree regional, we found that our robot was unable to climb the small steps. luckily a coach from 494 helped us build some 'sliders' out of some extra material the martians had (delrin, i believe), using a sawz-all and a hand drill. the sliders (along with a pneumatic cylinder) allowed us to get up onto the 6-inch platform in one bound.

the sliders are the white triangular pieces affixed to the front of the bot.

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

Half the weight of our robot this last year was in zipties. Colorful zipties. :D

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

The Original 229 Ghetto-Fab Moment:
(Sponsored by Tom Schindler)

This all goes back to 2002.
In the 2002 game, in order to pick up the soccer balls, we had this giant roller on the front of our robot. This roller was basically a giant wooden cylinder coated in grippy-foam, with a steel shaft running through it.

We picked up the soccer balls through sheer energy transfer. We spun that baby up to high speed, and as soon as a soccer ball touched it, *bam* it got blasted up through this alum shoot into the goal. It wasn't the most elegant method of the season, but it probably was one of the simplest, and it worked pretty darn well. (Who was at Cleveland that year?)

Anyways... we drove this massive roller with a drill motor. Off the motor we had a 1:4 timing belt reduction (do the math, that's 5000 RPM kids). It wasn't the neatest setup either. First off, with that kind of reduction, it took a few seconds for the roller to get up to full speed, but from there on out, angular-momentum did the rest.

The drill motor was kinda just, crammed into a timing belt pulley, and setscrewed in place. The wooden roller wasn't completely on center on the shaft, and neither was the driving pulley. This meant, the entire assembly oscillated like crazy. Basically, the entire thing was held together with good feelings and luck.

Ghetto enough?
Not yet dear friends... it goes on.

Now, because of the way that drill was mounted, the shaft was basically cantilevered. Yes... crazy stress concentrations.

At Bash @ the beach that year, about midway through the competition, the drill motor shaft just sheared right off. This left the pinion inside the timing belt pulley. With no way to fix it, we were in a tough spot.

Enter Tom Schindler.
Tommy "the man" Schindler was kinda bumming around that day, and hopped onto our pit crew for a while. (This making him, the first ever, honorary 229er. Tommy was the original 229-lover, everyone else is just copying him.)

So Tom was around when this happened. As we were all scambling for a soluition... Tommy just said something like "Dude. Just epoxy it back together."

What? Are you crazy? Hmmm... it could actually work!

So... we crammed that drill back into the pulley, tried to get it as straight as we could, and just slathered on the epoxy. It actually held up for the rest of the competition.

The moral(s) of the story:
-Epoxy fixes everything
-Drill motor output torque isn't enough to shear epoxy
-Tom Schindler is the man.


That's all folks. Anyone else?

JV

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

Enter team 1257... Let's see, where do I begin? I think I should make a picture with arrows pointing to different highlights of ghettofab on our robot.

1. Lift for hook/2x ball. Two hevy-duty 40 inch full extension drawer slides bolted together to make a 3 section lift that provides a height change of just under 80 inches. weight: ~20lb cost: $250
2. The winch that powers the lift is the FP with included wheel hub inside a short piece of that large aluminum box extrusion in the KOP
3. wall mounting hook purchased from Home Depot used for hanging. Personally, I think this is by far the best hook I have seen on any robot. It is very light (<8oz, I'd guess), cost about $8 and the only modification done to it was done by hand/hacksaw just to make the hook wide enough to accomodate the hanging bar. Additionally, it actually has two hooks (It's one of those hooks for like hanging a coil of hose. A 'U' with the tips bent in the third dimension to make 2 hooks.) making hooking easier, it supports the weight fine with only one hooked.
4. Our pride and joy, same winch from number two used for lifting the robot except for one awesome modification. A large, ratcheting socket wrench with a 2" socket attached to it to prevent back drive. This might disqualify it from ghetto fab, but we had a guy cut 5 slots into the socket so that it meshes with the spokes of the FP wheel hub thing. To make up for that, after the spokes became damaged and it looked like they might not hold, I globbed a bit of epoxy all over them to hold that socket in good and reinforce the spokes. We also achieved further reduction in gearing for this winch by double riggin the cable to the hook by simply looping the cable through the hook and fixing the end of it to the side of the winch.
5. Numerous pieces manufactured from sheet metal using sheet metal snips, a vice, and hammers.
6. For a while, we had a protective electronics cage made out of PVC and golf club shafts zip tied together. Personally that was far beyond my taste for ghettofab, it wasn't effective at all (Heavy and weak). We eventually replaced it some time during one of the regionals with a cage made with 1/16" thickness angle aluminum and 1/8" bolts and the construction methods mentioned in 5.
7. After changing the cage, we realized we were just about up for a match and the sign we had previously had on the cage either didn't fit or something like that, so I just wrote 1257 on a few pieces of 8 1/2x11 and zip tied them on.

As for the success of the parts. Most of it worked very well. The main exception being the winches. We had a good bit of problems with cable/rope getting jammed in them. We eventually resolved these problems relatively well. Also, the ratio of the winch used for lifting the robot is a bit high. Rather than triple rigging, I plan on turning down the FP hub a bit. Of course, if I don't get access to a lathe, I will just have to chuck the thing in a drill press and get cracking with some coarse sand paper :)

In contrast, now that it looks like we are going to secure some machine shops as sponsors, I am designing a summer project of mine (chasis and drive train) and CADding up every part. I will most likely be able to send the entire set of sketches to a machine shop, buy bearings, and hardware, and bolt the freshly cut parts together.

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

We used an orange piece of styrofoam as a bumper...and secured it on the front of our robot with zipties at the Annapolis Regional...I laughed when I saw it...funny stuff.
--Dori

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

At the Palmetto Regional, we needed to lose some weight so we traced our numbers (the numbers that you put on your house or mailbox) with a Sharpie, pulled the numbers off and colored then in with a Sharpie. Oh well, it worked.

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

The year is 1994. NASA and Carnegie Mellon University have spent nearly $2 million to build "Dante II," an eight-legged walking machine designed to enter the crater of the Mt. Spurr volcano in Alaska. We were staging the robot at the University of Alaska-Anchorage, and it was the day before final deployment to the base of the volcano. During the last reconnaissance trip to the mountain, we noticed two items as we flew over the crater: there was a lot of infall into the crater from the upper slopes of the mountain (the active crater was a secondary vent on the side of the mountain) which created a lot of mist and fog inside the crater as the material was melted by the escaping volcano gases, and we thought we saw some reflections from the bottom of the crater, leading to the idea that there might be a pool of water at the bottom of the crater.

The laser and its spinning mirror scanning assembly were housed in the purple cylinders at the top of the robot. The problem is that all the mist and fog would collect on the lenses of the laser scanner being used to map the terrain around the robot (the terrain maps were needed so the robot could figure out where to place it’s feet as it walked down the crater walls), and make them unusable. We needed something to protect the scanner from the falling material and floating mist. And we needed it quickly - we had about four hours before we had to start loading the robot on to the helicopter for the flight out to the volcano. What to do?

Time to run off to the Eagle Hardware store in downtown Anchorage. Grab a 30-gallon plastic trashcan with lid, and run back to the lab as quickly as possible. Throw away the trashcan (which makes for its own unique problems – have you ever tried to throw away a trashcan?), and keep the lid. Cut a round hole in the lid just big enough to fit over the scanner housing, and hot glue it on top of the robot. And that explains the big floppy black rain hat-looking thing at the top of the sensor mast on the robot. It worked great, and kept the laser and scanning mirror clear for the entire time the robot was inside the volcano.

On to the other problem. If there were a pool of water at the bottom of the crater, then it would be important to try to collect some of it for later analysis. The water would have dissolved volcanic gases in it that could lead to a better understanding of what was happening deep inside the volcano. This was very important to the science team. Unfortunately, the robot was never designed to collect water samples and we had no mechanism for collecting one. Just like the rain hat, if we were going to make something it would have to be done quickly.

Enter an empty Evian water bottle, the pull cord from a lamp, a piece of a vacuum cleaner attachment, a round wooden ball from Eagle Hardware, a plumbing fitting, and more hot glue. Voila! A liquid sample canister with a one-way valve that could be dipped into a puddle and would retain any collected water without spillage. Duct-tape it to the front left leg of the robot (look very closely at the picture and you can just see where it is taped in place), and away we go.

Both of these last minute additions worked perfectly. And it proved once again that “Apollo 13 engineering” techniques can work wonders – finding ways to use what you have on hand to solve a problem, by getting creative and discovering uses for items that were never intended (sounds like the early days of FIRST).

Of course, that was of little consolation when the grizzly bear gnawed on the robot the very next day, but that is another story…

-dave

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

Back before my time on 134, the teams rookie season to be exact, 9 years ago, the robot was being built, and it was nearly complete, except for one small detail, there was no drive train. So as rookies, the team decided to go direct drive with wooden wheels. Well no one really knew how to attach the wheels. Well one student *coincidently a former Clarkson student* said to the advisor, 'hey why dont we just epoxy the wheels on the motors'. Well they did that, and somehow managed to place very high.

Gotta love the epoxy


-Pat

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

Our whole robot was ghettofab, but here are some highlights:

1. Robot couldn't get up the second step, so we did the calculations and realized our arm wouldn't reach it. Everyone was thinking, "if only we could find a little hook-like object..." about a day before ship date we got an old theatre cane (the kind used to pull bad acts off stage) that we used on stagecrew. We drilled a hole in it and put the van door motor's shaft through it, and in turn bolted the van-door motor to the arm of our robot. The end result was a cane that could whip around and grab on to the bar (which it did!)
2. We didn't have front wheels, just some ghetto plexiglass "skids." In order to get up the steps we put a bunch of rollerblade wheels on the front of the bot. This worked suprisingly well.

Next year we have two new rules:

1. KISS sucks.
2. Zipties are evil.

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

At the 2004 Chatsworth Scrimmage our robot was very top-heavy and flipped over every match so we never got to use the hangar. We got to wondering what the robot would be like without the hanger, at least then we could climb the stair and shove other people off. So, we removed the 30-40 lb hangar and duct taped a Stack Attack bin lid to the robot to cover the drivetrain and other now exposed essentials and we played the next match. The robot did not flip at all but it bounced all over the place. So, to remedy that problem we went around asking every team for any spare metal they had and we duct taped it all together and then put it on our robot to bring it up to weight. I don't think we ever drove it that way though.

Towards the end of the LA regional we had a belt break on our hangar. Either we didn't have time to redo it or we couldn't find a turnbuckle so we used a zip tie to hold the ends of the belt together and tension it. Still works great to this day. On our 2003 robot Heather, we used a Zip tie to space a gear away from the chiaphua motor. That didn't last too long though.

On our 2004 robot, we had a lot of trouble turning so we sliced sump pump hose down the middle and zip tied it over two of the tires. It had ridges for forward traction but it would now slide sideways too. It turned like a dream. I think it was the cheapest fastest "omni wheel" ever made. We had a little trouble climbing the step so we switched over to pool hose which ripped and came off every match in the finals and it didn't turn nearly as well either. But at least we could climb the stairs.

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

So, heres 350's "ghettofab" entry.

That picture is of our 2004 ball collector (the drive train actually looks decent so it's not important) as it was at the BAE regional. Let me walk you through it part by part.

String- see all that neon yellow stuff? thats string and yess it is holding the frame together. Hey, tape cant be used to hold things together so string worked great. It gave the ball collector some flex too.

String 2- yes the white string going across the collectors sides is our "netting"

PVC Grippers- those white PVC things on top used to be the 2X ball grippers from the 2X arm we had until thursday of BAE. They are there so that they stop the ball collector from going inside the corral, they were added 3 matches in. Held on with bolts and string.

Wood- the frame pieces are wood, and the "L" brackets connecting them (where string isnt used) are metal. the metal and wood together looked terrible.

Wood 2: see those thin pieces of wood along the botton? Yep, scrap wood we picked up in the wood shop before heading to cometition friday. Added so that the balls roll better when we want to get them out.

Roller: the gray cylinder going across the front. A PVC pipe glued and bolted to the 2nd to last FP transmission gear (thanks to 121's great way to speed up the FP gearbox) with rubber stuff glued to the outside for grip. There is no axle, its held on to that little piece of scrap plywood (that is screwed onto the frame) using a 1/4 in bolt going through the end cap of the roller.

Winch: see that big hole on the plywood deck behind the ball collector? Well you can barely make it out but thats a seat motor we are using to raise and lower this thing. It's not speed controlled so the thing comes down as a controlled crash. The seat motor axle is spare key for the 5/8ths shaft. Oh yes, its 5 strands of string interlocked that we used as our winch cable. And no, the seat motor isnt strong enough to lift the ball collector back up all the way.

Pipe Insulation- spare stuff I have no idea where we got it but its used to cover the bolts holding the PVS grippers down and where the "winch cable" joins to the collector itself.

Oh yeah, you cant see it here, but our 350 signs were made friday morning out on the loading dock with spray paint.

No, the bot isnt painted at all. We dont have decorations except for all 20 or 30 of our license plate stickers.

Surprisingly the collector held up the whole competition. Although in our last match the front 2 vertical wood pieces snapped, so the entire top side was flapping around and flexible. Thanks to this, the ball collector could expand and actually hold more balls. So who else can say their bot works better broken?

<edit> sorry the picture is so small</edit>

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

Our transmission kept stretching just enough to cause the gears to go past one another instead of engaging. No picture of it, unfortuantely, but we ended up just wrapping it in a gazillion rubberbands... :D

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

OK, this is my team's specialty.

Flashback to 2003:
1) We were trying to figure out how to put the numbers on each side of the robot, so one of our software engineers actually took a popcorn tin, cut out a rectangle, and we put the numbers for mailboxes on it. Turns out, it worked quite well, even though it got torn to shreds. You can even see a snowman peeking through the numbers on the plate.
2) I counted, and at one point we had some 500 zip ties on our robot, holding everything together, including the gearbox and the motors.
3) For our stacking mechanism, which was built at the very last minute, we didn't have enough metal to finish the stacker. So we took some wood and cut it for the top of the stacking frame and the lifter. We then spray-painted the wood silver so that teams wouldn't notice that it was made of wood and thus vulnerable. We managed to fool everyone, even up close, into thinking that the wood was aluminum. That, my friends, is ghettofabulous.

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

1293 was surprisingly low on ghettofab, due to the fact that we had no duct tape.

I think the biggest ghettofab moment we had was when we couldn't find Mrs. Sutton (our honcho of nearly all things non-robot), who had printed up our team numbers for the robot. We had to have team numbers, so we used the best thing we could think of...electrical tape.

And it was like that the entire Palmetto regional.

Off of the robot, however, we were kings. We needed a ball tee to practice our autonomous mode, but we didn't have any toilet flanges or anything. Our tee wound up being a lid off of a foam coffee cup (the kind with the indentation in the middle), a length of PVC pipe to fit, and the feeder tray off of a printer to work as a base. (I wound up using tin snips to cut out a perfect fit in the ridges.) It worked for a tee--whether it held up when our robot came stampeding through is another story.

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.

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

i have to say First ghetto fab is definetly more creative then other ghetto fab just because of the fact that we can't use duct tape. But I have seen cars with engines held in there with just duct tape and zip ties.

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

Oh dear... This thread has most definitly been hiding from me.

2002. My rookie year.
We attempted a 4 wheel chain driven trannie. What's interesting is that we didn't bother using any pillow blocks to hold down our shafts. Instead we hand fabricated (hacksaw and drill baby) little 1" x 4" strips of metal that were bent over the ends of the wheel shafts and bolted directly onto the chasis. This provided for slack in our chain and really bad alignment. To make up for the slack we placed a thick piece of rounded off, I think it was some kind of polycarbonate plastic, directly against the chain as a tensioner.

Something like this would be able to be driven around rather gently on tile or contrete. But of course this was a robotics competition. Instead of tile, there was carpet and instead of gentle driving... well yeah 2 minutes and what are you going to do with a robot? So the chain would just pop right off it's sprocket and we'd be sitting ducks.

I'm still wondering why we bothered to build it that way (hmm maybe it was a weight issue), but what did I know? I was a rookie at the time. Unfortunately, this is the sole reason why 692 likes to avoid chain drives.

Minor gehettofabulousness: 2003. Robot's team numbers were shaped out of electrical tape and attached on with (colored!) zip ties.

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

If it was at Atlanta it could have been from us. I remember the ball, but I don't know what happened to the rest of it. We wrapped part of the ball around the grabbers on our robot to try and make them hold the ball better. It helped, but it didn't cure it completely.

We also had a problem with a shaft in our drivetrain gear reduction start binding on us in Atlanta. We had two gears on the shaft that were welded together with a spacer in between them, and we had them cotterpinned to the shaft so that the assembly would ride in bearings. After trying for a couple of hours to readjust the shaft to eliminate the bind, with no success, I had the idea to just remove the cotterpin and let the gears spin on the shaft. This worked very well, despite the fact that we now had steel spinning on steel, but it only had to last for 2 more days so why not go for it? We also got an added bonus by taking out the cotterpins in that our sprockets were now self aligning! :cool:

As for weight reduction, at Great Lakes last year our robot was about 3 pounds overweight. As a last chance attempt, myself and another team member got out our pocketknives and proceeded to trim the treads off the sides of our tires. It didn't get us 3 pounds, but when you have less than 1 hour left to be inspected for the regional, you'll do just about anything. :ahh:

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

well, our '02 and '03 bots were entirely ghetto. But last year we had about 3 days to ship, and we had no idea how to attach the flapper (think of a vaccume agitator)(SP and wrong term, but work with me). It was just some rubber strips screwed to a pvc tube. We were using the window motor to power it, we just got PC11, a high strength epoxy and glued to stupid thing on. It worked well for the 2 times we used it.

This year... ELECTRICAL TAPE!!!

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

http://www.chiefdelphi.com/forums/pi...&quiet=Verbose

'nuf said.
:D

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

Do you wanna see ghetto fabulous? Our robot was made out of wood, wires were hanging out from every direction and the drive train would always give out. It was so great. The name of our robot was "Robizzle", and the name of our bumpers were "Ghetto Foam". This was our rookie year and I am still proud of our rookie bot!

GO 1403!!!

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

Our 2003 rookie year still takes em all.....

http://www.rockwoodroboticsteam1098....t%2003%201.jpg

Plexiglass base, and practically everything else wood, with chicken wire protecting our "guts". We also quickly noticed a problem with our drivetrain and controls, since it was chaindrive, and we had a rather simple control system that consited of really only "on or off", so when we would go forward or reverse, the bot would jerk around a lot and almost tip over on several occasions. Our solution? We took a 1/2" piece of sheet metal, bent it into a loop shape, and bolted it onto the bottom of our bot. The result? Never tipped over except once when it ran up and onto another robot, it would constantly be bucking around and made for quite a celebratory dance :D

I distinctly remeber several teams asking us if we had gyroscopes on our bot.....

Our 2004 bot was rather "ghetto" as well.... I think the pic is self-explanitory...

http://www.rockwoodroboticsteam1098....s/Team1098.JPG

However, despite our incredible ghettoness on our 2003 rookie bot, we got 1st in qualifying and if I remeber correctly, got to the semi-finals of the St. Louis regional..... But I attributed that to luck :p

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

For the 2004 competition, we (1403) created ghetto foam at nationals. Back in the nj regional, we were hit from the side, causing our gearbox to smash. In order to prevent anything like that from happening again, we took foam, cut it into circles, and velcroed it to the wheels. Someone also drew some nice rims with a sharpie.

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

Team 1640:
Electrical tape and paint team numbers (http://www.team1640.com/gallery/disp...album=5&pos=33)
Bumpers made of pipe insulation (http://www.team1640.com/gallery/disp...album=5&pos=35)
And last but not least, the WaitGhetto function - it counted to a rediculously high number to act as a timer because we couldn't figure out how to do a proper timer!

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

1097: Rookie Year

We wanted treads, we knew we wanted treads, but Burko Belts definatly would break the budget, so we went around town till we found an old snowblower, and our robot was pretty much the bottom half of an old sowblower. Plus, our motors kept burining out (we were direct driving the treads, nor trannies), and that year in Sac they were doing the funky timing (15 min between matches, and then an hour between matches), and we had to replace a motor in like 10 minutes, so horay for the joys of zipties (and yes, you can run a match on Zipties).

Last season: Our accelerometor based navigation was not working, and R. Kevin Watson kindly donated a set of Greyhill encoders. The problem, our 200 hour drivetrain had no space to mount an accelerometer. The solution, a piece of flashing bent up to hold the encoder, attached to a piece of surical tubing which we affixed to one of the pins holding our transmission together.

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

2002 was our second year and we thought we learned so much from our rookie season. Our robot was almost entirely 1.25 square aluminum tubing. It weighed so much that we had to save weight any way we could. Instead of organizing the electronics neatly on some type of board, we just zip-tied everything somewhere on the frame. Wires and tubing went everywhere. When something went wrong it took forever to trace the wires and fix it. We placed last at the inaugural St Louis regional, but since we had a spot at EPCOT, we spent the elimination rounds designing some changes and hacksawed off the front half of the robot. The plan was to replace it with 1.25' PVC pipe that we brought to EPCOT. We spent the first day at EPCOT attaching the PVC with self tapping sheet metal screws. In the end our robot was half square aluminum tubing and half PVC. Our team numbers were printed on white label paper, except someone had the bright idea to print only one number per sheet.

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

Just a few weeks ago for the homecoming parade, we discovered that our OI's portable power source had been made and soldered with the wrong type of plug. So what did we do in our plight far far away from the robotics room? grab the wall adapter we were carrying, cut off the plug, strip the wire with our teeth (we had no tools), twist the wires together, and finish it off with using a little bit of electrical tape stolen form another part of the OI.

Another example of the ghettobot in action would have to be our team (114)'s HALF competition. It's an off season in team competition, where we basically make driving hunks of crackpot engineering. All that the really are is driving plywood boards with some sort of manipulator on top. Here's a few examples from last year.

http://engineer.la.mvla.net/robotics/images.php?view=323030352f48414c464d656469612f3034 48414c462d347468506c616365426f742e676966
http://engineer.la.mvla.net/robotics/images.php?view=323030352f48414c464d656469612f3034 48414c462d337264506c616365426f742e676966
http://engineer.la.mvla.net/robotics/images.php?view=323030352f48414c464d656469612f3034 48414c462d326e64506c616365426f742e676966

Watch the ghettobots spin!

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

They just hide the duct tape better these days.

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

In 2005, team 1318 had a problem while using the autoloaders. The refs were enforcing the rule that you actually had to be touching the triangle on the ground to grab a tetra, and although our chassis was easily over it, our wheels sometimes weren't far enough forward to be on the triangle when we grabbed the tetra. Luckily we weren't penalized for this the match it happened, but the refs warned us we had better fix the problem. Our solution was to hang zipties off the front of our chassis, so they would brush against the ground. Oh well, it worked. :rolleyes: