I am hoping to build my first CNC, and am thrilled at the possibilities after watching a few videos. I can't help but notice that most builds focus on framing a horizontal XY frame with very little vertical Z dimension. Any of the builds I see that use some vertical control use a drive screw system. I am wondering if this is absolutely necessary, or only used in the cases of heavy tool attachments that need leverage, such as the plunge force of a router. I ask because I am hoping to build a vertical XY frame for a CNC that moves around a small scanning device that weighs only 0.5 lb. I looked at the Acro system and wondered what would happen if it were turned upright so that the sliding arm stood vertical. My question is what would happen to the belt system and the motor's ability to hold my 0.5 lb scanner at a set height without drifting due to gravity. I ask because I can't help but notice that screw leads have a max length of about a meter, which kind of limits how tall my build could go. A belt driven vertical lift opens up taller possibilities. As I'm typing this, I now wonder whether setting the Acro system on end with the arm horizontal and the side rails vertical would then provide two motors holding the weight of the sliding arm and scanner upright, and perhaps two motors would allow for better weight support than just the one... Thank you in advance for the help!