FDM vs resin: why we don't print fidgets in resin
The two ways to 3D-print at home, and why one of them is wrong for hand-held tactile things.
Once or twice a month, someone asks why our fidgets aren't printed in resin. It's a fair question — resin prints look amazing and have detail FDM can't match. But for the kind of things we make, FDM (fused deposition modeling — layer by layer of melted plastic) is the right pick for at least three reasons.
1. Resin is fragile in the hand
A fidget gets clicked, dropped, pocketed, and clicked again ten thousand times. Resin parts are dimensionally precise, but they're brittle. Drop one and it shatters. Squeeze a thin section and it cracks. PLA and PETG, by contrast, will bend and recover.
If you've ever held a resin miniature and a PLA fidget at the same time, you already know this — they feel completely different. Resin is glassy, PLA is plasticky.
2. Resin chemistry is no joke
Liquid photopolymer resin is not food-safe, skin-safe, or kid-safe before it's fully cured — and "fully cured" is a process that's easy to get wrong in a small workshop. Even fully cured, some resins can leach. We're not interested in selling something for an ADHD kid to chew on if there's any chance of irritation.
PLA is plant-based corn starch. It's not food-grade (we don't recommend chewing or washing in a dishwasher) but it's well within "fine to handle all day" territory.
3. Resin is slow at scale
We run a small print farm. With FDM we can have a half-dozen machines running different items in parallel for hours. Resin printers are vat-based: one item per print, one cleanup per print, plus a UV cure step. The same throughput would need five times the machines and twice the floor space.
When resin makes sense
We're not anti-resin. If you're printing a tabletop miniature, a jewelry master, or a display piece you'll set on a shelf and admire, resin is the right tool. We just don't think it's the right tool for things you actually use.
If you want a deeper look at the mechanics that make a fidget feel good, the mechanisms guide walks through MX switches, magnets, and bearings.