It turns out that a printed pleat former is critical for holding the fabric in place and stretching it. Each of the comb clips is interlocking in multiple directions. There is a little dimple that can be seen barely on the lower clips near the tip that falls into a divot in the opposite side and through the fabric. The top and bottom are interchangeable except that there are unique end clips. It takes some force to unsnap everything when fabric is in the comb and it holds tightly.

The frame sidewall assembly clips are what I am working on now. I am trying to clamp the sides of the fabric securely while having a toolless assembly with no hardware just for design kicks and giggles.

I never imagined how a pleated filter might take such a complicated build. Currently at 32 parts. Forgive the poor print qualities in multiple parts. I sped things up and made massive layer heights for drafting purposes. This is the third full scratch iteration.