This video documents an ambitious project to 3D print an entire kayak in under 24 hours using a custom-built treadmill-based large-format 3D printer. The creator details the significant upgrades made to his "improper extruder," including structural reinforcements, enhanced cooling, an optimized hotend mount, and improved insulation, all aimed at maximizing extrusion speed and material flow. To achieve the rapid print time, the kayak model was specifically designed for "vase mode" (spiral mode) printing, allowing for continuous, non-stop extrusion. Despite facing challenges like heat management and minor print hiccups, the kayak was successfully printed in 20 hours and 51 minutes of practical printing time. The video concludes with the highly anticipated, yet challenging, maiden voyage, where the kayak's design flaws, particularly its lack of a cover and stability issues in waves, led to it taking on water and eventually breaking, causing minor injury to the creator. The video ends with a call to the audience to suggest redesigns for a more user-friendly and functional kayak.
Summarizing the 24-Hour Kayak Print:
0:00 Ambitious Goal: The creator aims to print an entire kayak in under 24 hours using his custom treadmill 3D printer, a significant improvement from a previous 7-day print.
0:23 The "Improper Extruder" - Speed Focus: The key to faster printing is a high-flow "improper extruder," which achieved 600g/hour in tests, theoretically allowing a 14kg kayak in 24 hours.
0:50 Extruder Mechanical Redesign: Addressed previous hotend mounting failures by redesigning parts with heatset inserts for durability and maximizing belt width.
1:41 Powerful Extrusion: The extruder uses two belts, a 3:1 belt reduction, and a Nema 23 motor, capable of extruding at 90 Newtons of force continuously at 60 mm/s.
2:19 Larger Nozzle for Flow: Swapped from a 1mm to a 1.8mm nozzle (larger than filament diameter) to achieve even faster extrusion rates, demonstrating a standard 3D printed "Beni" object's filament equivalent extruded in just one minute.
3:01 Addressing Heat Management: Identified heat accumulation as a major challenge with high extrusion speeds. Added two powerful cooling fans and reprinted machine parts in ASA for increased stability against shaking.
4:20 Combating Heat Creep: To prevent nozzle clogs from overheating, a new hotend mount was designed to be CNC machined in aluminum (sponsored by PCBWay) to act as a heatsink.
5:33 Hotend Insulation & Belt Preparation: Added extra insulation to the hotend to maintain temperature at max speed and built a contraption to flatten the treadmill belt where the nozzle lays down filament. The old belt was replaced and cleaned for maximum stickiness.
6:46 Software Optimization - Vase Mode: To eliminate non-printing travel time, the kayak was designed to be printed in "vase mode" (spiral mode), ensuring continuous, non-stop extrusion with two wall layers.
9:08 The Printing Process: The print started at 9:51 AM, with 2kg spools lasting 4.5 hours. Multiple overnight spool changes were required to meet the 24-hour goal, involving continuous monitoring and cooling assistance.
10:38 Successful Print Time: The machine reported 20 hours and 51 minutes of practical printing time, resulting in the kayak being printed in less than 24 hours, despite minor hiccups like insufficient cooling and a nozzle snag.
11:51 Post-Processing & Waterproofing: The kayak underwent sanding, 3D pen touch-ups, and a flap disc treatment. Internal cavities were added for foam flotation, and a full epoxy coat was applied to ensure watertightness.
12:47 Maiden Voyage & Challenges: The kayak was transported via a modified bike cart. Its launch into the waves quickly revealed stability issues and a lack of a cover, causing it to take on water and eventually break. The creator sustained a minor leg injury from the sharp edges.
16:53 Call for Redesign: Concluding the challenging experience, the creator asks viewers for suggestions on redesigning the kayak to be more human-friendly and functional for a future attempt.