In this humorous and practical presentation, Johannes details the process of creating custom chocolate pieces designed to fit the 42mm Gridfinity organizational system. The talk outlines a multi-stage maker project that begins with 3D printing a "positive" mold, then using a vacuum former with food-safe PETG plastic to create a "negative" production mold. Key techniques for working with chocolate are covered, including a simple method for tempering and the use of a dental vibrator table to effectively remove air bubbles. The project culminates in two distinct applications: first, a "nerdy" Gridfinity-based advent calendar, and second, a more traditional advent calendar built using a laser-cut wooden frame, demonstrating how modern maker tools can be combined to create unique, personalized culinary gifts.
Crafting Gridfinity-Compatible Chocolate and Custom Advent Calendars
0:00:13 Introduction & Food Safety: The talk introduces Gridfinity as the "opium of the nerd" and begins with a critical food safety disclaimer: do not use 3D printed parts directly for food molds; instead, use them to create molds from food-safe materials.
0:01:45 The Problem with Standard Chocolate: The speaker demonstrates that common chocolate bars, like Ritter Sport, are incompatible with the standard 42mm Gridfinity system, necessitating a custom solution.
0:04:20 Designing & 3D Printing the Positive Mold: To create the chocolate shape, a custom 1x1 Gridfinity-compatible block is designed in CAD. It's made low-profile and includes a cylindrical cutout to serve as a finger grip for easy removal from the grid. This "positive" is then 3D printed.
0:05:18 Vacuum Forming the Negative Mold: A sheet of food-safe PETG plastic is heated to 150Β°C and vacuum-formed over the 3D-printed positive. To prevent the PLA positive from melting at this temperature, it was printed with a high (80%) infill for thermal stability.
0:07:46 The Art of Tempering Chocolate: The speaker explains that tempering is crucial for restoring chocolate's crystal structure, ensuring a professional, snappy texture. He details a simple method using a microwave and "seeding" the melted chocolate with a solid piece to initiate proper recrystallization.
0:08:54 Removing Air Bubbles with Vibration: To prevent cosmetic flaws, air bubbles must be removed from the liquid chocolate after it's poured into the molds. The speaker humorously reveals his effective tool of choice: a dental vibrator table.
0:13:31 Application 1: The Gridfinity Advent Calendar: The finished chocolates are placed in a Gridfinity base. A cover image is printed on photo paper and precisely cut with perforated "doors" using a Cameo 4 plotter. This creates a functional, albeit very "nerdy," advent calendar.
0:16:32 Application 2: The Traditional Laser-Cut Advent Calendar: To make a more universally appealing gift, the speaker designs and laser-cuts a wooden frame. The pre-cut photo is attached to the frame, and the chocolate pieces are glued behind their respective doors, resulting in a classic advent calendar made with modern tools.
0:20:42 Q&A on Degassing Methods: When asked about using a vacuum chamber instead of vibration to remove air bubbles, the speaker explains he prefers vibration due to its speed, better food safety in a shared makerspace, and the risk of the chocolate "boiling" under vacuum.