Quote Originally Posted by Ollie78 View Post

When beginning to draw up a design, is it better to find the sizes of linear rail and ballscrew that are readily available and size the frame to those existing components. Or just draw the machine out to the desired size and worry about those after?

Are Nema 23 steppers a good fit for a machine of this size, 1200mm maximum assuming a twin ballscrew design on the Y axis?
Which would you like to do? I started my machine around 3 years ago, and at that time I was nervous about ordering from China. I designed my router to the size I wanted, worked out rail/ballscrew dimensions, found a uk supplier who sold standard sizes, and redesigned to use the next off-the-shelf size up. Hiwin rails cut easily with an angle grinder but ballscrews need fiddly end machining which is beyond most people at home. These days, I would probably spec exactly what I wanted and order from someone like BST Automation in China.

Nema 23, 3Nm or (better) 4Nm, would be fine for X and Y for this size machine. Important parameter is motor inductance, so check back before buying! But at least you have a frame size for planning purposes.