The latest articles on DEV Community by PYXL (@pyxl). https://dev.to/pyxl https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4222428%2Fa1e65dc9-d641-46c5-b0af-2adf334b818e.jpg https://dev.to/pyxl en PYXL Mon, 02 Nov 2026 15:33:33 +0000 https://dev.to/pyxl/we-built-exactmelt-free-melt-value-calculators-for-gold-silver-platinum-palladium-and-coins-44oo https://dev.to/pyxl/we-built-exactmelt-free-melt-value-calculators-for-gold-silver-platinum-palladium-and-coins-44oo <p>You're holding a gold chain from a drawer, or a jar of old silver dimes. A buyer offers you a number. Is it fair? To know, you need the weight, the purity, the spot price and some arithmetic in the right units. Scales read grams or pennyweight, spot prices are quoted per troy ounce, and a troy ounce is not the ounce in your kitchen. It's easy to get one step wrong.</p> <p>So we built <a href="https://exactmelt.com" rel="noopener noreferrer">ExactMelt</a>: a free site that does the arithmetic, shows its working, and then lets you compare the offer with the value of the metal.</p> <h2> What it does </h2> <ul> <li>Pick the metal, enter the net weight and the purity, and get the fine metal weight and its value at spot. For example, 10 g of 14K gold holds 5.833 g of fine gold.</li> <li>Use grams, pennyweight, troy ounces, ordinary ounces, kilograms or grains.</li> <li>Type in the buyer's offer and any fees to see the offer as a share of the metal value.</li> <li>Add several items to one mixed lot, for when a buyer quotes a single total for gold and silver together.</li> <li>Preview a worksheet as a PDF, copy a link to the calculation, or save it on your device.</li> </ul> <h2> What's inside </h2> <ul> <li> <strong>4 metals:</strong> gold, silver, platinum and palladium, each with its own calculator. The <a href="https://exactmelt.com/gold-melt-calculator" rel="noopener noreferrer">scrap gold calculator</a> covers 8K to 24K and fineness marks from 375 to 1000, plus a custom purity.</li> <li> <strong>31 coin entries</strong> in the <a href="https://exactmelt.com/junk-silver-calculator" rel="noopener noreferrer">junk silver calculator</a>: US silver dimes, quarters, halves and dollars, war nickels, 40% Kennedy halves, Eisenhower dollars, the American Silver Eagle, and Mexican and Canadian silver coins. You can count coins, rolls or face value, and use standard weight or your own scale reading.</li> <li> <strong>Copper penny and nickel calculators,</strong> which also state that US rules restrict melting one-cent and five-cent coins.</li> <li> <strong>Converters:</strong> troy ounce to grams, pennyweight to grams, troy ounce vs ounce, gold-to-silver ratio.</li> <li> <strong>Guides</strong> on hallmarks, plated vs filled gold, and how to test gold and silver.</li> </ul> <p>That adds up to 52 pages, each built around one question people actually ask before selling.</p> <h2> Who it's for </h2> <p>People checking an offer on scrap gold or silver, anyone sorting inherited jewellery or a coin jar, and hobbyists who want to see the maths rather than trust a number. There's no account and nothing to sign up for.</p> <h2> A note on how it's built </h2> <p>It's a Next.js (App Router) site on Vercel. Spot prices come from gold-api.com, and each page that uses a price prints the time of the quote, so you can tell how fresh a figure is. Each metal result lists its inputs: fine weight, fine troy ounces and the price per ounce. Melt value is the metal at spot. Buyers pay less after costs, and the site says so instead of pretending otherwise.</p> <h2> What's next </h2> <p>More coins, more item types, and clearer guides for the questions people ask before they sell. If there's a coin or item you'd like to see, tell us in the comments.</p> <p>Try it at <a href="https://exactmelt.com" rel="noopener noreferrer">exactmelt.com</a>. A chain and a kitchen scale are enough to start.</p> webdev showdev tools nextjs PYXL Mon, 02 Nov 2026 13:28:55 +0000 https://dev.to/pyxl/we-built-origami-tutor-free-paper-craft-lessons-you-can-turn-and-replay-in-3d-50ji https://dev.to/pyxl/we-built-origami-tutor-free-paper-craft-lessons-you-can-turn-and-replay-in-3d-50ji <p>Paper diagrams are hard to follow. One arrow means "fold behind", another means "reverse fold", and after step 12 you're holding a crumpled square, wondering what went wrong. Videos are easier, but they run at someone else's speed, and the one fold you need is gone in half a second.</p> <p>So we built <a href="https://origamitutor.com" rel="noopener noreferrer">Origami Tutor</a>: a free site where every lesson is a 3D model of the paper that you control.</p> <h2> What it does </h2> <p>Pick a model and you get the whole lesson, one step at a time:</p> <ul> <li> <strong>Turn the paper</strong> to see the fold from any side, including the back.</li> <li> <strong>Replay any step</strong> as often as you like, at your own pace.</li> <li> <strong>Read what the step does</strong> in plain words under the model.</li> <li> <strong>Print the diagrams</strong> as a PDF when you'd rather fold away from the screen.</li> </ul> <p>Each model card also tells you what you need before you start: the difficulty, the number of steps, and the paper size and shape, including how to cut a square from A4 or Letter paper.</p> <h2> What's inside </h2> <p>There are 391 lessons, and it keeps growing:</p> <ul> <li> <strong>260 origami models:</strong> animals, boxes, flowers, toys and classics like the crane and the paper fortune teller;</li> <li> <strong>25 paper airplanes,</strong> from simple darts to gliders;</li> <li> <strong>68 paper-cutting projects,</strong> plus quilling, pop-up cards, paper flowers and decorations;</li> <li>seasonal ideas for Halloween, Christmas and other holidays.</li> </ul> <p>If you've never folded anything, <a href="https://origamitutor.com/easy-origami" rel="noopener noreferrer">start with easy origami</a>. It lists the shortest models first. If you have kids at home, the <a href="https://origamitutor.com/paper-airplanes" rel="noopener noreferrer">paper airplanes</a> section usually wins.</p> <h2> Who it's for </h2> <ul> <li> <strong>Beginners</strong> who gave up on paper diagrams.</li> <li> <strong>Parents and teachers</strong> who need a quick craft for a rainy afternoon, a class or a party.</li> <li> <strong>Folders who already know the basics</strong> and want a harder model without guessing at the hard steps.</li> </ul> <p>No account and no sign-up. Open a model and start folding.</p> <h2> A note on how it's built </h2> <p>The 3D view isn't an animation someone drew. Each lesson is built from a model of the sheet itself: every fold is computed, and the paper never stretches. What you see on screen is what you'll hold in your hands. Building that took much longer than the website around it, and we may write about it separately.</p> <h2> What's next </h2> <p>More models, more crafts beyond origami, and better guidance on the steps where people most often get stuck. If there's a model you'd like to see, tell us in the comments.</p> <p>Try it at <a href="https://origamitutor.com" rel="noopener noreferrer">origamitutor.com</a>. The crane is a good first challenge.</p> webdev showdev learning tools