shroomzofdoom Posted June 5, 2022 Posted June 5, 2022 (edited) I was hoping to use this thread to share things people are trying with the new 69762 & 69761 gears. Below are some things I just discovered. Curious what you might be finding? Please share! Background: I build mostly crawlers and off-roaders so I almost never use open differentials. Even on new Lego A models (42069 & 42070 for example) I design out center diffs and lock the axles during the initial build. I'm crazy like that. I know all the reasons why I shouldn't, but that means you already know the reasons why I do. So when I saw the new gears in the Ferrari Daytona set (42143) I bought my first Technic supercar solely for the purpose of checking out the 69762 & 69761 gears. While I will get around to building the car someday, technic cars just don't excite me like motorized trucks do. I had to detour for a bit to see what was possible with the new gears. Here are a few things I've found so far... The larger 69761 gear obviously wouldn't have an axle hole... ...which implies there's no easy way to lock the diff without locking one of the outputs. It does like you could easily connect up to 5 different outputs to one input if you had enough of the smaller 69762 gears. I only have two at the moment Lastly, I found this interesting... Like most things Lego, the geometric proportions seem to elegantly flow to other elements. This doesn't permit locking up the larger gear in way, rather the larger gear acts as a bearing race allowing the smaller gear to be turned effortlessly inside of it's larger companion. Edited April 24, 2023 by shroomzofdoom Quote
Thierry-GearsManiac Posted November 3, 2024 Posted November 3, 2024 (edited) Recently getting some 69762 gears (from the 42168 John Deere 9700 Forage Harvester), I wondered if, despite their design for a single use case, they could be meshed in another way : what if we tried to mesh two of these gears together ? Because they can mesh really better (thanks to their true conical shape and bigger teeth) than double beveled gears. The optimal angle of the two axles would be 2 * arctan(14/22) = 65° approximately. Therefore I tried, for several angles close to this value, how to mesh these gears as closely as possible (mitigating/eliminating backlash) without putting pressure on them (they must spin freely) : I built these test benches in order to eliminate tilt backlash for the axles (they are guided on some length) as well as the flexibility of the structure. In each case, a specific height adjustment was necessary 45° (135° axle hole connector) : needed 0.8L = two plate heights : 53.1° (bent liftarm) : 0.5L = half brick width : 60deg (120° triple axle hole connector) : 0.2L = one stud height (look at the stud-terminated pins) : 67.5deg (112.5° axle hole connector) : needed 0L : Therefore, would there be any use cases ? Sci-fi doors, orreries etc... Edited November 14, 2024 by Thierry-GearsManiac Transforming links to image links, now that they work (HTTPS enabled) Quote
shroomzofdoom Posted February 1 Author Posted February 1 On 11/3/2024 at 4:35 PM, Thierry-GearsManiac said: Recently getting some 69762 gears (from the 42168 John Deere 9700 Forage Harvester), I wondered if, despite their design for a single use case, they could be meshed in another way : what if we tried to mesh two of these gears together ? Because they can mesh really better (thanks to their true conical shape and bigger teeth) than double beveled gears. Those are very cool Thierry! I'm sad to say that the only creativity I could muster on using them in locking differentials involved kra-glu and a drill. 😁 Quote
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