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.
- 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
- 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
- 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.
- 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.
- Numerous pieces manufactured from sheet metal using sheet metal snips, a vice, and hammers.
- 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.
- 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.