rack and pinion.

[greencactus3]

has anyone tried to use a rack and pinion mechanism on their robot before? well, with a cylinder pushing the rack. not a motor spinning the pinion. that ive seen. also seen screw drives or w/e theyre called.
so, i would like to create a rack and pinion mech. few problems tho.
1. this is for the OCCRA competition. and in its rules it states NO precision tools allowed. ex) no cnc.
2. well, theirs lotsa rules, but mainily, unless we can hacksaw a flat gear rack from angle aluminum, we'll hafta use a chain as the rack.
3. no welding.
so, first q.
how to mount a piece of chain securely with no slippage to a piece of flat or angle aluminum without welding.. i was thinking zip ties, but i hope sumonell think of sumthing a bit more reliable.
next. how to keep the "rack" straight without falling off the sprocket. (remember, the "rack " is connected to a cylinder.)
and then the main question. is this gonna work?

so, anyone ever tried this idea of creating a rotary force with a cylinder before? we need a minimum of 140 degrees of motion. our cylinder we chose is a 2in stroke. so with a small sprocket, cant be too hard. except the chain may break? i dunno.

ps. no rotary cylinders in our kit...


well, we hope sumone can tip us on what would be difficult, improbable, easy "shortcuts" or even a picture of an example, it would be greatly appreciated.
main point.. we want help!!! aaand oh, one more problem. our first competition is coming up REAL soon!