Train with space for electronics and batteries in carriage.

thingiverse

This train engine features space for integrating electronics, allowing a 10mm LED to fit seamlessly into the front, and a 16mm button that perfectly slots onto the smoke stack. Sufficient room exists within the cab and boiler area to accommodate an Arduino/Compatible Pro-Mini, while my own design squeezes in a JQ6500-28 MP3 SD Card player module and mini speaker in the cab. The delight is clear as this train roars to life when you press the button, unleashing random train sound effects or kid-friendly songs in tandem with dazzling colour changes on the 10mm RGB LED. Such unbridled joy - a testament that at 40 years old, the thrill of operating this device remains unwavering. For power, an innovative solution utilises an old USB cable measuring 5mm in diameter as a conduit between the cab and carriage. This convenient setup enables space within the carriage for up to four AA batteries along with a mini boost converter if needed (in my case, four alkaline cells arranged in 2S2P provided stable 3v performance down to 1.6v and reliable 5v power via a booster). Notably, "wheels" on this model are permanently fixed in place - a deliberate design choice given the intended age range of two years or less for safety reasons. For securing the roofs in place, one may require drilling additional holes as these screws are custom-fit. Notes and tips: The coupling pin proved susceptible to breaking off when attempting removal; instead, an M4 nut and bolt offered a suitable substitute, whereas a more elegant solution involved harnessing the inherent structural integrity provided by the USB cable itself. During printing, however, problems with wheel ovality at the base arose due to inadequacies in slic3r support generation. Inspiration for this train's original design stemmed from the renowned Thingiverse contribution, modified and refined using Tinkercad. Enhancements included integrating fixed wheels, hollowing out internal space, amputating the roof for enhanced portability, adding precise screw mounting points, and graciously omitting the pointed cow-catcher to avoid compromising aesthetic appeal. To augment strength and facilitate effortless movement, a generous application of 5-minute Epoxy was applied to the underside upon completion. Simultaneously, securing the front LED in place through a deliberate coating also proved effective in ensuring its long-term viability. Subsequent application of liberal amounts of hot glue provided added electronic stability. A professional-grade acrylic coat finished by varnish ensures this magnificent train engine's radiant appearance remains resplendent for years to come. This marvellous model, painstakingly crafted with meticulous attention to detail within Tinkercad, invites your creative input - visit the link provided to edit online and make it truly one-of-a-kind. https://www.tinkercad.com/things/2rXZmPWC1gv