Yet another newbie question

[alexis221]

Hi all, I love this site! I am in the design faze of my cnc router 3 axis. It's going to be 3ftw x 4ft long. The bed fram is most likely be made from metal stock, but I will prob. use aluminum for the gantry. I am having problems with finishing my design because I need to know things like...what size motors I would need and what type and size ballscrews I should get. I like to go over board in terms of size for future use on a bigger machine and more power. I am trying to save on the materials for the frame and rails to get better motors and electronics. I see stepper motors on ebay but the voltage ratings and the other specs are a bit confusing....Someone please help...Thanks.

[ger21]

Typically, you choose a target velocity and acceleration rate that you'd want, and then choose your components to meet those requirements. You'll also need to know the amount of weight you'll be moving to do the calculations. Most stepper manufacturers have motor sizing programs available for download. Check out www.orientalmotor.com and http://www.danahermotion.com/

[alexis221]

Thanks. What should be the avaerage velocity and acceleration rate for average production on wood and light metals? Also, should I build the frame and gantry first then take my weight and measurments from that for motor size and ballscrew measurents? Thanks for your input....I need all the help I can get.