tamiya 3 speed truck gear box

thingiverse

Update 4/1/2020 Changes I've made: The inner shafts are now five-sided. This change allows for more meat on the first drive gear and the shafts are hollow to accommodate a 2.5mm hanger as a metal inner shaft. I've also changed the shift shaft to a metal 2.5mm hanger with a locking spacer in the middle, which can be used on both ends like e-clips but finds it unnecessary. I'm gluing all the parts on shaft one to make this more solid with the metal hanger in the center. I'm also gluing the ends of shaft two, end one and end two, because if you don't, there will be enough play for middle gear to skip. Additionally, the box separator bars are hollow to allow for a metal hanger insertion, but only the two top ones that hold the shaft one supports are necessary to prevent middle gear from skipping. I've also made this gearbox compatible with 540 and 550 motors because I'm using the 550 in my Tamiya truck. This will allow people to upgrade to the new three-speed gearbox without having to deal with the hassle of figuring out what to do with a different motor. To be honest, I prefer the 550 setup better. The 540 motor is too fast, but the 550 has enough power to pull but not too much to drive indoors. Update: This gearbox now uses 6700ZZ bearings. I've added diagram STLs and picture diagrams of shaft one and shaft two, as well as a shift shaft reference to one of the completed STLs. The combined print STLs are set so that number one is closest to the motor on both shafts. Two hints: Print everything on rafts and use a marker to label the parts while they're still on the rafts. Also, use white grease on all bearing surfaces and gears while assembling it, but avoid using any other kinds of oil as ABS and PLA absorb oils. I didn't do this initially because I was busy printing, adjusting, reprinting, and getting all the parts to mesh properly. Now, I have to take the whole thing apart again to apply white lithium grease on the bearing surfaces. If I've completely confused everyone, consider my day complete – just kidding! If there are any questions about this gearbox, don't be afraid to ask; it's extremely complicated, and I made it so that there aren't as many parts but still ???? I've been playing with my Tamiya truck, and the one thing missing in my uploaded King Hauler is a single-speed gearbox. While it works at mid-range, it doesn't have the extreme power of the Tamiya gearbox, so I've wanted this gearbox for some time to put into my truck. I'm going to use this transy in my next truck, which will be a heavy wrecker triple axle rotator, and I want the most powerful transy possible. This gearbox seems to work really well, but the shift arm requires creativity to find the right spring weight. I've looked through my springs and found some that came off of one of my G-scale train engine; they're larger round but have the correct length and are light enough for a servo to shift it without being too powerful to bend the shift arm. The shift arm is made for e-clips, but I didn't have any at the time, so I used some wire to wrap at the e-clip positions. At this point, I don't see a way to make this with bought bearings and still be 3D printed, but I'm considering figuring it out. This was the most complicated gearbox I've created to date, and I hope I don't have to do any more like this; it was a nightmare trying to figure out how the thing worked without tearing apart my expensive truck.