spinnetti

Jerry,

There's no drawings since I work completely in CAD and didn't do any concepts. Went straight from brain to parts design. I ordered a couple random differentials off the internet, one was just too stiff for this scale (would have been ok for 1/8th or 1/6th scale maybe) and the other just right. I 3d printed the housings and brake drums which key to the output sockets on the differential. I also bought some "dog bone" axles, and cut off one end on which I mounted a pinion gear to power the final drive which is also scale and is inside the housing on the exterior of the hull, just like the real thing. There's about a 1:3 reduction in the differential and a 1:15 reduction in the final drive so 1:45 overall reduction. I 3d printed "brake bands" out of flex material and it works just like the real thing which also used brake bands on the output drums. One end is connected to the servo arm, and the other to the differential housing. Basically, if you look up how the real thing worked, this works the same way, only I have a single speed transmission instead of multi-speed. My system definitely works better than the multi-motor/gearbox arrangement of Tamiya copy-cats. (though the Tamiya Sherman had a scale type system with twin clutches which was very cool).