Howdy! If you haven’t seen it yet, there is a new variant of the Toughbox Mini called the Toughbox Mini S which touts that the “gears are now symmetrical.” The 2023 Kit of Parts chassis includes two “T23” Toughbox Minis with symmetrical gears for the second stage but a 50 tooth gear that is flat on one side with a boss on the other, seemingly a mix of gears from the existing Toughbox Mini (now the Toughbox Mini Classic) and the new Toughbox Mini S.
In previous years, the Kit of Parts chassis has come with a 10.71:1 gear ratio with a 16 and 48 tooth (asymmetrical) second stage but this year that has been switched out for an 8.45:1 ratio with 19 and 45 tooth (symmetrical) gears and a 3/8" hex spacer.
The ratio table on page three of the included Kit of Parts user guide and the parts list on page six correctly identify this, but page 10 of the manual as well as the new AM14U5 gearbox assembly video incorrectly identify these gears as having 16 and 48 teeth although they visibly show the 19 and 45 tooth gears.
If you are expecting your kit of parts chassis to perform similarly to previous years you will instead find that it runs about 3.5 feet per second faster with a little bit less than 80% the pushing power.
tl;dr: the Toughboxes in your kit of parts have a different gear ratio than previous years which will give you a faster robot with less pushing power. The new instruction manual and assembly video call a 19 tooth gear and 45 tooth gear a 16 tooth gear and 48 tooth gear. You still need to pay attention to the orientation of the boss on your 50 tooth gear (boss to bearing).
We’ve been running the 8:45 w/ 4 NEOs for a few years now, and so I consider that to be an advantage to most in this game. Good to know. Also, the gear bosses installed backward have been the reason for the gearbox not freely turning (test by rotating with wheel by hand after built) most often, so good tip.
Notably this will decrease the mechanical advantage from having to backdrive the chassis gearbox in order to begin rolling down a tilted Charging Station. Tomorrow we will compare the old 10.71:1 toughbox ratio to the new 8.45:1 toughbox ratio on a tilted Charging Station simulacrum. Both robots will have CIMs in brake mode, we will let y’all know what we find.
@DuckGWR Thanks for pointing this out and sorry about the error in the guide! The updated guide is now available on the new product page:
We had initially intended to supply this years AM14U5 with a complete Toughbox Mini S but, as I am sure everyone is getting tired of hearing, due to supply chain issues, we couldn’t get enough new 50T gears made in time so we had to resort to a mix of old and new, plus the spacer, for this year. Versions of this chassis after this season will include a complete Toughbox Mini S and will likely allow you to select which ratio on the chassis page.
Please note, the E clip grove location on the Toughbox S output shafts is different than the Toughbox Classic output shaft. This shaft will be available for purchase separately at this link in a few days.
Let us know if you have any other questions, and again, sorry for any confusion.
