I found that non orthagonal mounting of the scope caused cone error where the scope and guider are not pointing in the same direction as the mount axis. As well as backlash , worm adjustment and even a loose puck. Many errors in guiding get worse over time particularly in the west with a lot of weight and balance issues.
You can order the Rowan kit in oz pretty quickly if they have one. Easy to do. Works very well.
https://www.siderealtrading.com.au/p...elt-drive-kit/