I love the Freewell filters for the Osmo Pocket, but I hate the carrying/storage case that they come in. Not only is it really hard to open, but it's designed for 8, even though I only bought 4. Not only that, but the filters are hard to pry out of the tiny foam slots.
I wanted minimum storage space and easy access for 4 filters. So here is my design.
The filters fit into the rack perfectly, but they're just sitting there, so if you turn the rack over or flick the rack, the filters will fall or flip out. I'm glad to be careful and I decided it works good as is, and it wasn't worth it to me to do the additional design work that would "trap" the filters in place, but still make them easy to get in and out of the rack. This design totally works for me.
The rack is narrower than the filters, so it's easy to lift out a single filter because you can grip directly on the edge of the filter with no interference. And it's equally easy to place a filter back into the rack. And in both instances, you have no risk of getting your finger oils onto the filter surface.
Print the shell on it's flat end so that it's sticking straight up off the bed with the opening facing up. I didn't need a brim for this. It stayed put just fine. An you don't need supports for the rack. The slot underneath will "bridge" just fine.
When you go to slide the rack into the shell, the little slot on the bottom of the rack will be tight (which is good). But don't just shove the rack into the shell because it'll be near impossible to get it back out at first. Instead, slide the rack into the shell a little bit and pull it back out. And do that over and over, slowly progressing the rack further into the shell as you "wear down" the mating surfaces a tiny bit and gradually loosen it up. After about five minutes and fifty to a hundred or so progressive insertions, you'll find that you get a nice snug fit that moves quite easily.
Print the rack with a layer height of 0.10 in order to get the best accuracy on the slot on its underside. I printed the shell multiple times, using every layer height from 0.10 to 0.30 and it seemed to work fine in all cases. The numbers on the outer surface end up looking the best if you print the shell at 0.10.
Check out my other Osmo Pocket Accessories:
https://www.thingiverse.com/thing:3361263 Tripod Stand with 90 degree power
https://www.thingiverse.com/thing:3321058 Stand and Tripod mount
https://www.thingiverse.com/thing:3383057 Wireless Tripod Adapter