COINOOK — The Smart Shopping Cart Coin & Bag Hook

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🦏 COINOOK — The Smart Shopping Cart Coin & Bag Hook

🌟 Like & Collect to keep it handy!

If COINOOK made your shopping smarter, hit that 👍 and ⭐ — your next grocery run will thank you!

The Problem

Picture this: you arrive at the supermarket, grab a cart, and dump your reusable bags in the child seat or the small upper basket — the only flat, protected spot in the cart. But now that space is gone. Eggs? Squished under bags. Fruit? Rolling around the main basket. Your toddler? Competing with a pile of tote bags for the seat. 🤦

Every single shopping trip, the same trade-off: bags vs. fragile items vs. kids.

The Solution

COINOOK replaces your coin and solves the bag problem in one move.

Inspired by the unmistakable silhouette of a rhino, COINOOK is a 3D-printed cart coin that does double duty. Slide the flat end into the coin slot to unlock your trolley — the cute horn-shaped hook stays outside, giving you a dedicated place to hang your empty reusable bags on the side of the cart handle.

Your bags stay accessible but out of the way. The child seat stays free for your kid. The upper basket stays clear for eggs, bread, fruit, and anything delicate. When you're ready to bag your groceries at checkout, just grab them off the hook. Simple. 🎯

One insert. Two problems solved. Zero compromises.

🦏 Why "COINOOK"?

Coin + Hook = COINOOK. It unlocks your cart like a coin, hooks your bags like a hanger. And that curved silhouette? Look closer — it's a little rhino! A friendly shopping companion that quietly does the heavy thinking for you, so your groceries don't have to suffer.

Features

🪙 Universal Cart Coin — Fits standard European trolley locks (Wanzi and similar systems accepting 50c, 1€, 2€ coins)

🛒 Bag Hook — Hang 2-4 reusable shopping bags from the horn while you shop, keeping them off your cart space

👶 Free Your Cart — Child seat and upper basket stay 100% available for kids, eggs, fruit, and fragile items

🦏 Rhino-Cute, Rhino-Smart — That adorable curved silhouette isn't just for looks — it's engineered to hold your bags at the perfect angle

🧲 Stays Put — The flat coin section locks into the cart mechanism; bags hang from gravity — no clips, no magnets, no moving parts

🎒 Keychain Ready — Loop holes in the handle let you attach it to your keyring, carabiner, or bag so you never forget it

🖨️ Support-Free Print — Despite the dramatic horn curve, the geometry is optimized for zero supports — no cleanup, no waste, no stringing under the hook

Print Settings ⚙️

Printer: Bambu Lab A1 mini Slicer: Bambu Studio v2.05.00.66

All other settings are default from the Bambu Studio profile — just slice and print, no tweaking needed.

💡 Tip: PLA works perfectly fine for this model. For extra durability, print in PETG — that's what I used for my daily driver. The coin section undergoes repeated insertion/removal stress, and PETG's flexibility gives it a longer life. Same profile settings work for both materials.

Print Stats 📊

☕ Less than a quarter of an hour of actual printing, less than a single espresso in filament cost. Your little rhino is ready before your coffee gets cold.

Who Needs This? 🎯

• 🛒 Anyone tired of bags stealing cart space
• 👶 Parents who need the child seat FREE
• 🥚 Shoppers who want a safe spot for fragile groceries
• 🌱 Reusable bag users (because you're already saving the planet — now save your cart space too)
• 🔑 People who always forget their cart coin at home (put COINOOK on your keyring!)

Design Notes 📐

COINOOK is a single-piece print — no assembly, no hardware, no supports. Just slice, print, and go shopping.

🎯 Yes, you read that right: NO supports. Despite the aggressive rhino horn curve, the overhang geometry has been carefully optimized so the entire hook prints clean without any support structure. That sweeping curve isn't just aesthetic — every angle was engineered to stay within printable limits while maximizing hook depth and bag-holding strength. This means zero post-processing, zero wasted material, and a smooth finish on the hook surface where your bags actually slide on.

The coin section is calibrated to standard European trolley mechanisms (tested on Wanzi carts). The hook curve is optimized for bag handle width and weight distribution. The two small holes on the body serve as keychain attachment points and also reduce material usage without compromising structural integrity.

🦏 Your little rhino. Big help.

Unlock. Hook. Shop.

Designed and tested by Ambrosinus DEV Design Space 

Ambrosinus DEV
Design Space

lucianoambrosini.it