StevenEvan I only just noticed this post. This sounds very plausible to me. At 5 steps per count, it would be 5760/5 = 1,152 counts per turn (revolution) about the same as the Celestron focus motor at 1,000:counts per turn. It would achieve much the same result as a timing belt, without any mechanical changes. I if it could be done at driver level so much the better.
The timing belt solution also greatly improves back end clearance which is very tight on my Evolution 8 but just manageable.