While we see plenty of very impressive 3D printed objects complete with plenty of moving designs, few building projects are more inspiring than Eric Harrell’s PLA working replica of the Toyota 4 Cylinder Engine 22RE. To refresh your memory, Eric’s recreation is a reverse-engineered engine that has been scaled down to 35% of the original size, as this was simply the largest possible option for his own RepRap Prusa 3D printer. Assembled with magnets, the 80 different components probably took up about a whole 1KG roll of PLA filament and took more than 34 hours to completely print. ‘It's definitely a challenge for you and your printer,’ Eric said.
But that was last January, and now Eric’s already back for more. Going for a larger and more complex model, he has now 3D printed the four-wheel-drive gear box for his previous model: the 5 speed transmission Toyota 22RE. It’s a fully working miniature replica of that matches his previous project, complete with a reverse gear. Like the engine, it’s not for the beginners. ‘This model is more complex than the engine,’ he writes, though it is in fact far more complex to assemble.
“If one was to build either of my transmission or engine, they would need to have a pretty good idea of how to put an actual engine together since these are modeled after real parts,” Harrell told us. “Which is great, because most people that are interested in 3D printing would never get the opportunity to actually rebuild an engine or transmission.”he says. Of course, as its plastic it can never be a truly working transmission, but its moving on the exact same concepts. ‘If it was somehow scaled back up to full size, and made out of a more durable material than PLA it should be a fully working transmission,’ he argues.
While the majority of the transmission is 3D printed, there are some smaller parts which can not be printed on a desktop 3D printer, such as the 3mm rod, (18) 623zz bearings, (20) 3mm washers, and a few other small odds and ends like screws and bolts. At the same time, Harell doesn't ensure that all the parts will be ready to go off of the printer. Depending on the 3D printer used, some of them need to be scaled up or down in order to fit properly.
“The transmission works exactly like most manual transmissions found in any car or truck,” explained Harrell. “However, I can barely explain how it works. It’s fairly hard to grasp unless you assemble one or see an animation of one opened up.”
Regardless of the time required for printing and assembly, this has to be one of the most incredible designs that we have come across yet on Thingiverse. Most incredibly, Harrell tells us that it could absolutely be used in a real vehicle, since it is a scaled down version of the real thing.