I don’t remember who said it, but one of my core design philosophies is that the best design is the simplest one that works.
That is the idea behind the RCH Wallet.
It is a minimalist card holder/wallet with a twist — or actually, a curve. That curve is where the “Radius” in the name comes from, but it is not just cosmetic, or even just to help the holder feel more natural in a pocket. The main reason it is there is because the curve is part of the retention mechanism.
I made a flat version of this months ago and never posted it because I didn’t like relying only on a friction fit along the sides to hold the cards in. Different filaments, printers, and cards can all change the fit slightly, and that can lead to people needing to scale the model. That is not ideal, especially when you don’t even know exactly what cards will be going in it.
I kept working on it, and eventually the old engineering phrase popped into my head:
Everything is a spring. IYKYK
The cards themselves are a spring. If you give them a slight bend, they want to go back to straight. So by giving the wallet a radius, the cards are held in with their own spring force instead of relying only on a precision fit.
The card access was another part I wanted to keep simple. A lot of minimalist wallets use a lever or mechanism to push the cards out. Some of those stagger or fan the cards, and I understand the idea, but I’ve carried one of those wallets for years and never found that feature especially necessary.
Most of the time I want the front card, the back card, or I just need the stack pushed up enough to sort through it.
So I went with the obvious solution: a cutout where you can just push the cards directly.
That is really the whole design. The cutout is the access mechanism. The radius is the retention mechanism. No lever, no spring, no moving parts, and no card launcher.
Not because those things could not be designed, but because I do not think they are needed here.
That is what I like about this one. Some engineering can create a cool wallet with clever spring and deployment mechanisms. More engineering can sometimes get the same job done without needing those extra mechanisms at all.
I genuinely prefer this over the popular-brand metal minimalist wallet I was carrying before.
Card Fit
This first version is designed around six cards.
With six cards installed, the holder feels secure and smooth to use. Five cards still holds very well. Four cards are still retained better than I expected. At three cards, there is not enough stack thickness so thats when going upside down could let the remaining come out.
Depending on the cards and filament, you may be able to fit a seventh card, but I am calling this first drop the 6-card version.
RFID / Key Cards
This is not RFID blocking.
For this design, I actually see that as a feature. If you carry a hotel key card, work badge, access card, or something similar, you may be able to use it without pulling it out of the holder.
Daily Use and Material Notes
I have printed and tested this in PLA, PETG, and silk PLA, and they have all worked well for me.
PLA should be fine for normal everyday use, but I would avoid leaving it in direct sunlight or in a hot car. If heat resistance is a concern, PETG or something similar is probably the better choice.
Having said that, the one I have been carrying every day for months is PLA.
I also did some extremely scientific strength testing.
I took the more brittle version, which was silk PLA, removed all the cards so there was nothing inside supporting it, put it in my back pocket, sat on a wooden chair, turned it backwards, plopped down on it a bunch of times, and generally tried to break it.
It did not break.
I’m calling that good
Printing and Customization
The print stands up and does require supports, but the supports are included and pretty minimal. They are designed to come off cleanly.
It is a relatively fast print and uses very little material, which should make it a solid seller item for anyone offering printed products. I think the perceived value is well beyond a typical material-markup pricing strategy.
The body is split into narrow bands/stripes so colors can be changed easily in the slicer. You can color individual bands, group bands together, make thin accent stripes, wider color blocks, school colors, team colors, business colors, or whatever else you want to try.
If adjacent stripes are assigned the same color, they will merge automatically when printed. The splits are there for color control, not to force visible stripe lines.
Future Possibilities
I think this will also be a good candidate for future textures. A leather-style texture would make a lot of sense on this, and a golf ball dimple texture could be a fun version too.
Other sizes may come later depending on interest.
For now, this is the starting point: the 6-card RCH Wallet, ready to customize in whatever colorway you can come up with.