SaperPL

Someone just commented under my video that there's a turntable like that in the Xiaomi Orion Six-Legged Titan Robot (XJXL03IQI): This one is two studs bigger than the one I designed - the gap between mounting points here is 11 studs, while mine has 9 studs between the mounting points. Actually, this would potentially be a good piece for my project, but I can't find it online...

I printed both of them in PLA for the prototypes I made and they did slide well, I don't really know how it'd turn out with PETG, since I feel like PETG is more flexible, I'd expect it also to have a bit more friction maybe? And yeah, they did change some of the things for production - that was expected. As for the teeth inside - I wanted to match the aesthetic of the current version of the turntable as well as allow putting of one inside another for example for transferring some additional inputs this way and the additional teeth on the same ring didn't feel like something that would make sense to me. Also I've been considering a third piece that would be a gear rack sliding between those two with some hole openings to transfer additional rotation, but it I didn't figure out how to make those cut outs in a meaningful way at the time. Maybe I will follow up on this at some point as single additional input could be useful to drive gun elevation in tanks.

I'm following up on this situation here: Trax spotted the part in the wild, so we assume I can spill the beans on this one now: Here are the 3D printing files: https://www.thingiverse.com/thing:7303823

Another update: Braked differential steering taken out of the differential frame has the problem that the whole thing has a lot of friction and in a model of this weight it matters. Maybe I could figure out how to print a custom frame for such differential, but then I'd also need to implement different type of breaks on the sides of the differential, and I doubt it would be much smaller width-wise than in the huge implementation of this kind of steering inside a frame between two turntables that I did some time ago.

Really cool build. The pneumatic extension is really weird but a cool idea. Good luck :)

I'm not a fan of the knob actuated mechanisms right where they are because it doesn't make sense anymore apart from worm gears holding the angle, but this truck looks great. Another clean design. I need to dig myself out of current projects and start building some of your trucks.

Seregiz has built this truck in red:

Amazing build, the trick with hands is really cool. Great work. Now I want to see full race of such go-kart builds :D

Looks really good, but there's something wrong with some of the photos where the red looks to be pink - would be good if you'd fix that. Also I feel like either windshield is one stud too far back, it should stick out a bit more, or the cab is one stud to short, or just the angle in the photo is just a bit weird - with that said, some more photos with different angles would be nice. Finally - shouldn't the topic show some progress on the project as well ?

Interesting project. Just that double fender makes me think about the rest of the shape back there.

Shameless plug for reference on the doors: You can do fairly compact door mechanism fitting within 3 studs and then incorporate the motor into the roof where a lot of modern busses have some HVAC units. You will most likely not make photos showing the ceiling of the bus from the inside, but most of the photos will show the messy floor, that's why it'd make more sense to make clean floor with mechanisms moved under the roof. I remember Sariel has also figured out some clever door system for his tram recently, so you could look that up as well. I like the trick with one-rings on the steering rack. I was wondering if the size is actually useful for things like that.

Figured out how to do the ammo rack in curve with this 15x15 girder (still not in white, so 3d printed for now) reference photo (with ammo racks empty):

The rules state it's supposed to be a non-branded vehicle.

@Jim Two questions: Does wheels needing to drive the vehicle means they need to be douching the floor for driving or can they be used in the drive system in some other rotary action to propel the vehicle? For example used as clutch in drive system, used as drive sprocket in a tank, used to transfer rotation input to some walking system? Will taking out springs out of shock absorbers be treated as part modifying?

Update on the progress. Improved the chassis thanks to some new parts. Still waiting for some DBG panels to be available from Lego: