screenshots i sent to the eBay seller showing the three parts drift with time. The master has a sparkfun part found precise over more than a year
1 ran at night, 2 at morning, 3 during the afternoon
edit: Sorry, for some of the screenshots, got message below.
“There was a problem during the uploading of 2019-05-28 19_50_05-master3.txt - Notepad.jpg.
Your post has been made, however the above attachment was not attached. Please use the Back button to edit your post and submit any required changes.
Your attachment has failed security checks and cannot be uploaded. Please consult the forum administrator.”