Kyosho Ultima ST GP RS-148 gearbox idler gear

thingiverse

Okay, so this is a Kyosho Ultima ST GP (Racing Sports version) gearbox idler gear. Part nr. RS-148. I've printed tens of versions of this gear to tweak this design. This is the latest and final version for the stock input gear style. This has 1.4mm wider teeths than original, pushing the limits of space with stock input gears. All these particular gears inside Ultima ST's gearbox are mod 0.8 gears. You can't use this gear with stock genuine Kyosho input gear! You need to use my input gear. I've made that available, and it works perfectly fine with stock differential case/gears. My RS-148 gear set is designed specifically for this purpose, but I'll release a super wide differential set later. I suspect this widening process will give a great boost to the durability of your gearbox (especially when printed with our FDM style printers). The gearbox gears are all mod 0.8, so this gear is easy to print even with stock 0.4mm nozzle. This uses standard-sized bearings. Remember, your first layer needs to be on the correct level. If it doesn't quite fit right, you might need to slightly sand the gears' teeth from the print bed size to have a smooth turning gear. I didn't encounter any problems with my Prusa i3MK3S. To get the best results, try "driving in" your gearbox by spinning the input shaft with a cordless drill for a few minutes, then opening it up and applying new grease. I'll later upload part 2 of this RS-148 gear set, which is the gearbox input gear (which I've also widened to the max). Top tip for input gear: If you want the best gearbox input gear to replace your plastic one, check out ARRMA part nr. AR310762 - it's a direct swap and offers full-width teeths on a steel gear that goes straight onto the 5mm axle Kyosho uses. Just be sure to shim its level to match the input axles' gear locking pin level. You can see what I mean by this in my rc10talk build thread. With ARRMA input gear, you can maximize the benefits of this wider idler gear. With stock input gear, the benefit is only 0.4mm for the input gear/idler gear combination and 1.4mm for the idler/differential gear combination. As always, use good quality grease in your gearbox and make sure your slipper is adjusted properly. Enjoy and drop a comment on how it worked out for you, or if you want any changes to be made! Also check out my other parts I've made for the Ultima ST Racing Sports/Type-R/Evolution chassis. Here are links to my project: https://www.rcuniverse.com/forum/rc-nitro-stadium-trucks-243/11675757-my-ultima-st-gp-type-r-evo-20th-anniversary-project-3d-printed-cf-parts.html https://www.rc10talk.com/viewtopic.php?f=30&t=44634