Quote Originally Posted by JAZZCNC View Post
I see no point in having 2 ballscrews to drive the Z axis.? Whats the thinking behind this.
Your just making the motors work harder and increasing costs for no practicle gain.? You'd be much better spending the money on a second ballnut and creating Zero backlash.!!
Hi Dean,

Yeah, what i was thinking, you got me there . I started the design half an year ago, and learned a lot during this time.The thing is that i wanted not only to have 2 ball nuts but also 2 extra ball screw supports, " 4 is better than 2 " to resist the vibration. Thats why the double ball screw. Also the double ball screw saves on the total Z length.

Now i am not so sure. Still its not too late. Now i see that i could have made the ball screw machined so that it accepts double support at the ends. I have an extra ball screw at home, longer, i mean. Then the only thing that needs changed will be to buy 2 longer Hiwin rails to compensate. Have to rethink that. There is still time.

Now going this way of thinking i start doubting if i should not make the whole z axis 100mm longer and have travel of 300mm instead of the 200mm as its now. Could just raise the vertical bars on the sides of the base with 100mm without compromising any integrity. They are ~80mm high right now. the thing is would i really need that extra 100mm and for what?