Sync problem at post with Red Weapon and 688

Hi Guys,

I just finished my project last week. I found after i sync everything together, video and audio got slightly offset.  Camera was Red Weapon 8K, my recorder was sound devices 688. I jammed the tentacle from 688 everyday before we shoot and used tentacle to jam Red and i left tentacle attached with RED weapon. we shot on 24 fps.

At post, i found at beginning of the day, audio and video had 1 or 2 frame offset, and the end of the day, audio and video got around 12 frames offset. we normally shot 12 hours a day, and i didn’t jam tentacle in the middle of the shooting, just let it run for the whole day.

is anyone got a idea here or know what it wrong here? why i have the offset?

Thanks Guys