If you’d prefer a video example that is more or less what most people on this forum would do for a basic flexible pack, https://www.youtube.com/watch?v=yMLsBxPpj00 is a good example from @ShutterShock.
Edit: I forgot he used precut strips on that, but similar can be done with 30 mm strips cut for each end of each p group.
Got you, now it’s pretty straightforward to me.
Now it’s the time to search for 30 mm nickel…
UPD: okay, that was easier than i thought. Thank you
My suggestion for longevity with actual flexibility: use silicone super flexible wire for the joints and lock the p groups together.
Any flex at the p group level will break your welds or nickel or both. I use tesa tape (the fabric kind not the fuzzy kind) to insulate the cells plus fish paper where appropriate, neutral cure silicone to glue the cells because i think it holds up better than hot glue, and then strapping tape/fiberglass reinforced packaging tape to add more rigidity. Then i like to heat shrink them to seal them up using more silicone to make the group as waterproof as possible and cut out little holes to solder the series connections… then hit the connections with hot glue to seal it back up.
I have used flat braid successfully for the flexible series connections but failures have happened and a few of them have been reported on here. The consensus after the discussion iirc is that the braid just isn’t quite flexible enough and the silicone wire series connections is bomb proof as long as you don’t have anything rubbing… which will kill anything you use to connect. On mobile so no example pics but if you scroll way up there are lots of good examples
Post your progress pics, id love to see your progress. Good luck
Her are some pics i fount that kinda demonstrate what i mean. here i have flexible and non flexible sections on an 18s 8p pack. the non flexible sections are built and the series connections (c in your drawing) are done with flexible braid. its my opinion that the flexible braid can flex to get installed but after that it doesn’t move again. just not flexible enough for how many micro bends and vibrations we run into. ymmv
Then the inflexible sections are connected across the flex point with silicone wire. the lengths here are a bit excessive and shorter lengths would work if the points i was connecting were closer but if you look through a lot of the pics up thread there is usually a significant bend or slack added to the flexible series conductors, it gives the wire more room to move and not translate the vibration to the connection point and also a little length so that if you aren’t quick with your solder and it wicks up the wire you aren’t left with a rigid connection point that will fail.
here is another 18s pack that i made more recently and shows how i seal everything back up with hot glue through the heat shrink and a little better length on the series connections.
Yeah, I definitely will. Already ordered fishpaper/nickel/cells and so on as well as other hardware.
Damn it’s too cool to make your teenhood wishes come true by just snapping your fingers 
And thank you for pictures, i will definitely use them as reference.
Luckily enough, i have spare 10AWG silicone wire pieces from old builds.
And just sharing my thoughts, I am not a native speaker, so I have already forgotten how much language practice esk8 brought to my life in past.
