Hi. I'm a newbe here but I've been lurking for quite a while. I've been deciding a long time on buying a mill to make aluminum parts with and have finally made up my mind to do it. In all the information I have gathered from this wonderful web site and by surfing the web I feel that the X3 Grizzly model will be the best mill I can afford at this time. I want to convert this mill as cheaply as I can at the start and then keep upgrading and adding on it over time. But now I have some questions on some of the parts I have decided to start with.
First – I am getting my electrics from http://www.kelinginc.net as they seem to be the most reasonably priced place so far. I'm a little confused on the stepper motors though. I'm looking at the torque-speed curve of the NEMA 23 BIPOLAR STEPPER MOTOR 425 and the NEMA 23 BIPOLAR STEPPER MOTOR 282. The 425 starts out high but rapidly falls as speed increases whereas the 282 has a better curve by the looks of it. Of course the torque starts out lower but at 2000 pps the smaller of the two has more torque. Then at 3000 it looks really sad for the big motor. First of all is 2000 pps an average speed I would be looking to machine 6061 aluminum on the typical X3 conversion? I would probably be looking to hook the motors up directly. Does anyone know where the most common speed falls? I need to get this machine to be as productive as I can and need the best speed at making the part as possible.
Also I need to order the aluminum for the motor mounts does anyone have the size of the stock I should be getting? I also need couplings to connect to the acme rods and would like to know the sizes that I need to look for. I have no way to turn the ball screw rods to the proper dimensions as yet but I plan to add a small lathe to my arsenal later.
Thanks for your help.