This is my second image using my CEM120. During the acquisition of the first image, the mount presented regular spike in the RA axis.
To correct this issue, I pulled the axis apart and cleaned everything. Aluminium dust was present on the worm and after the cleaning and regreasing the spikes observed during the first use of the mount have disappeared.
This time the mount was smooth and worked perfectly. The image was acquired using 3nm narrowband filter and the exposure time is 28h6min.
Astrobin link:
https://www.astrobin.com/6szupt/