Oh, gotcha.
You are right about that, Joe. I would not try it (chain) as a rack and gear setup.
Now, if you were to make the chain taught from one end to the other, and have the driven sprocket on the gantry, with the chain going under an idler, over the drive sprocket, and under another idler, then that might work, but....
In reality, the cost of chain and sprockets is only a little less (perhaps 50 bucks or so) than using gear rack and spur gear.
Trust me, I found out the hard way
