Are these Star shapes/trails do to backlash?

[jm_rim]

After many frustrating nights, I'm finally beginning to have some success. However, then going through my images from last night, I noticed that many of the frames had small star trails (I guess), see the image. This is on every 3rd to 6th exposure, in all the others the stars are “perfect”.

I polar aligned using SharpCap and took a successful 200sec test shoot, but used 120sec during the night - just to be safe.

Can this be do to backlash? 

 

My setup, SW EQ5 with RA motor, SW 150PDS, and a Nikon D5300.

Edited January 6, 2021 by jm_rim
added info

[andrew s]

Can you provide some more information.  What is the orientation of the image RA / Dec? Were you guiding? Was it windy?

Regards Andrew 

Edited January 6, 2021 by andrew s

[jm_rim]

12 minutes ago, andrew s said:

Can you provide some more information.  What is the orientation of the image RA / Dec? Were you guiding? Was it windy?

I was shooting IC 348 (RA: 03h 44' 36", Dec: 32º 10' 00") and the image i attached is very cropped in. 
No guiding (still on my wishlist 😁) 
No wind and -12º

[andrew s]

Sorry I not clear enough . Is the shift in RA or Dec or a combination. Looks like the RA drive is sticking then slipping occasionally or possibly periodic error. Hopefully, someone with experience of this mount will comment. 

Regards Andrew 

[jm_rim]

1 hour ago, andrew s said:

Sorry I not clear enough . Is the shift in RA or Dec or a combination. Looks like the RA drive is sticking then slipping occasionally or possibly periodic error. Hopefully, someone with experience of this mount will comment. 

Regards Andrew 

Sorry, it is in the RA direction.

If it is the RA drive that is sticking, how can this be solved ?