{project}-backups folder zip file additions

When do the zips in the -backups folder get created? Can I force one to be added?

Also, why does an archive zip created from the project manager include all the files in the design folder but the -backups folder auto-created files exclude all files not used by the project?

TIA

Automatic backups are made when you save the schematic or PCB, so to trigger an extra backup you just have to press [Ctrl +s], but there are some limitations. There is a minimum time between backups, and you can configure some other settings in KiCad / Preferences / Preferences / Common / Project Backup. But there are also some other conditions that trigger an automatic backup. IMHO, it happens too often. I often find a whole lot of backups from days I just opened the project for viewing, but did not change anything. I may investigate further when I’ve finally made the switch from KiCad V8 to V9. The intended goal of the automatic backups is solely for emergency situations, such as a crash of KiCad or of your whole PC.

The Archive all Project Files from KiCad’s project manager does not:

It only backups a fixed number of file types. I find it a quite useless function because I do not have enough control about what it backups. For example, I make project documentation in asciidoc files, but KiCad ignores the .adoc files during this backup. To do some tests, I just now extracted a few of the automatic backups in the backup directory. And then I did the “Archive all Project Files” thing, and it also included the just extracted copies of the project. I do find backups important, but I can’t remember the arbitrary rules that KiCad uses to decide what to put in such a backup. Therefore I have marked this method as unreliable and do not use it at all (Except for the testing I just did).

The automatic backup is designed as a safety feature for having some saved state of the KiCad project in case KiCad crashes, or in case the user wants to get back to a previous state of the design but they do not use a proper version control system. It only backs up certain files because it is not designed as a general-purpose backup for any files, but a specific backup for the KiCad project files.

This explains the erratic behavior I’ve seen. I’ve decided to do my own zip backups of files and subfolders I chose which I manually move to the backup folder with my own date-timestamp prefix naming convention.

Same strategy as I use. Manual creation of zip files with date prefixes in ISO_8601 format, so they automatically sort in chronological order. Often I also have a text file in which I log big changes with their date and that file gets zipped too with the project.

I have tried git a bit. It’s quite powerful, and commits can be automated to a high degree (and also automatically written to a backup device such as a NAS. Problem is that I can’t really wrap my mind around the complexity of GIT. And GIT repositories also tend to grow very big. Much bigger then a bunch of sets of zip files. For projects which have a lot of meta data (such as many datasheets, photographs or whole logged HTML sites) I use a “big / little” backup. If the meta data changed a lot, I backup the whole project. If the meta data only changed a little, then I only backup the the KiCad project (and /or uC source code).
It’s not perfect, but it’s good enough for me, and simple to understand, so I won’t make mistakes. Biggest disadvantage is that it takes a minute or so to make the backup. You could use a batch file, makefile or some (python) script to add some more automation (Including the backup copy to another drive), but I never did that myself.