Originally Posted by
peteeng
Hi TiBoy - I'm guessing the ratio, as in the video the belt is closed up in a casing. Unless its a gearbox but unlikely to be a gearbox. The quote max speed is 8000rpm so maybe its a 5000rpm servo and smaller ratio? They do steel with light cuts. The vids look good but there are machine aspects that are poor. Like they run the ballscrews directly to the motors with no thrust bearing, so motor life is at risk specially if shock loaded. They use a leadscrew for the Z for some reason as well. The machine assembly videos are quite good so you see how they are doing various bits of the machine. I suppose if its in a commercial environment and gets a few 1000 hrs on it the owners will know. It does have some vibration as in one vid you can clearly see the chatter in the finish then it gets cleared in the spring cut...
In regard to the pulley diameter you pick a small pulley that works then get a big pulley to suit. 3:1 is common on various things. So you must have a space problem