I finally have a plan for my router. I am going to build a 24x48 machine. I am building the machine totally out of 3/4" thick 6061 aluminum plate. I can get that pretty cheap where I work. I am going to use round linear bearings and hardened shafts for the motion system. 1" for X double 3/4" for y and double 5/8" for Z. I will most likely use ball screws, but I haven't totally decided on that part yet. I'm thinking something around 5/8" diameter. My main concern now is the electronics. I know most on here recomend the Gecko systems. My question is what size motors, drives, power supplies should I use. I will be cutting harwoods mostly, like oak. Maybe some light milling or engraving in aluminum, but nothing heavy. I don't want to overdo it, but I want it to have some rear end too. Also what is everyones opinion on the screws and couplings. Belt drive or direct? Anyway like I said I am ready to satrt building, I just want to clear these things up before I proceed.
Brad, if you read more, most people will suggest supported rails as a superior alternative to round shaft -- even with large diameter shafting, 48" is a long span for unsupported rails. But enough unsolicited advice .
For a machine this size, a Nema 23 G540 based solution makes a lot of sense. And if you're using stepper motors, you will want to go direct drive to take advantage of the lower end torque stepper motors provide -- a belt is not really necessary unless it helps with your mechanical mounting for some reason. We have sold tons of our 3 and 4 axis kits to people making machines around this size.