gyenesvi

Thanks for the kind words, glad you like it!

Thanks for an official review of this car! Good to get some info about its design from yourself, explaining some choices and limitations. I'd be curious about the desing of the new CV joint part. Can you share a few words about that? In particular, what was the reason of creating a single 5L part instead of a 3L male one with an axle end that would slide into the existing male part with an axle hole? Some of us were hoping for such a part, as that would have allowed it to be used in various circumstances, creating various lengths including fracrional ones by means of the two pieces sliding. Have you considered such a solution? If yes, did you find any serious drawbacks of it that lead to this single-piece solution? Sometimes understanding such choices can just make fans appreciate the end result more :) Thanks!

Thank you!

I would actually not be surprised if it was just a recolor of the Mindstorms hub. Maybe with proper support for BLE. But yeah, the 'isBatteryOperated: false' flag points in a different direction. Though might be that a battery is not operated by a battery; it is a battery itself :D But that's getting too philosophical..

That was my other reasonable guess regarding that recently discovered new item (previous page) with number 88013 (which is close to other PU motors and batteries) and dimensions about 10 x 11 x 6 studs (which maybe the box dimensions).

This is what I actually thought when I wrote that even hard coupling could work; that you could even go back to the initial version but without the center diff and keep the motor layout and rear diff lock if you wish. I think at this point it's worth building a proof of concept chassis just with the drivetrain in place to see how it works in reality with these wheel sizes and gearing ratios. If there is no noticeable sliding of the wheels, I'd definitely go on with this version because the drive motor placement is quite space efficient here, leaving room in the middle for other stuff (and you can make a decision about the diff lock later, whether there will be space for it or you need the space for something else).

Well I would definitely recommend Studio building. It's much easier for bodywork, because you can build 'in the air' without parts yet being properly connected, and it's much faster to iterate and see how the overall shape will look. Plus it costs you nothing to build with all parts in existence, and see in which colors parts are available. And in the end when you try to build it, you'll see where it needs more stabilization (also, that's something fairly easy to predict without actually building it if you already have experience with structures, and is less demanding than building a strong chassis or mechanisms). It's definitely worth looking at others' builds, the bodywork is usually pretty visible just from pictures, without buying instructions..

Thanks for the kind words, with practise we learn :) True (when there's enough space and parts to make it possible), and I also think it can make structures cleaner when you think modularly.

The flat roof completely changes its character, it gets more of the boxiness of the real one, much better this way! Besides the overall continuity of the surfaces is really good in almost all areas. I wonder if the side of the nose and the doors could be improved a bit? I see you using the 2x5 wing panel with the 2x3 extender on the bottom of the rear side. Could that combination maybe used on the bottom of the nose on the side as well? Would make the bottom edge more aligned to the real one? Also, on the same side section, the area under the flex cable on the edge is a bit fuzzy. It seems to me that a 2x5 winglet could fit in there better maybe? On the doors, you use 4L + 5L + 9L liftarms. Could that be built with 9L + 9L liftarms to decrease the number of breaks? Or are you using the L part of the 2x4 L shape? Maybe use 13L + 5L in that case, the 5L being an L shape? Also, on the upper rear part of the door, there is that intentional gap above the long wing panel. Behind that there seems to be a short wing panel in black (seen from the inside of the door). How would that look with a red panel behind, more like in the real one? I think sinking the black beam one stud behind would make it look more realistic, and could give space for implementing some kind of curvature. I hope you don't mind all these suggestions from all the people. Believe me, you get that because the model is soo good that everyone wishes to get it closer to perfection :)

It looks simple enough :) And now you are just one step away from the almost perfect gear ratio in the same amount of space: instead of 16:16 use 12:20, and then instead 16:20 downgearing use up-gearing by 20:16. The total will be 0.75, whereas 81/107=0,757. I don't think you really need a diff lock this way. If you do, then you can still build it permanently locked at the rear withou changing anything but the diff. I'd focus on other functions on this one. As for autonomous features, for one it would be indeed nice to program it to sweep an area by moving in lines and turning around in the end. Add the obstacle avoidance and it's already quite cool :) By the way, with such a perfect gearing ratio, even hard coupling the motors could work..

As for somebody working with autonomous driving technology (for regular cars), autonomous tractors sound like an interesting area that unfortunately I don't know much about, so following the building of one in lego form will be interesting :) It's quite an ambitious project to place all those hubs and motors, but the shape of the tractor seems to be a good fit for it, great choice! I love the idea of the detachable cabin in the real thing, nice solution for transitioning towards autonomous operation while still having a possibility to drive it manually. Can you tell what tasks such tractors can typically do themselves? Are they following preprogrammed paths or are they mapping the environment themselves and making some decisions? I guess you'll use the distance sensor for obstacle avoidance, right? Do you plan to implement moving along a programmed path? Regarding the differentials in the drivetrain, I find this a bit overcomplicated. It seems to me that the diff lock is on the rear axle only, which seems a bit pointless given that there's a central diff as well. I'm guessing that even doing away with the central diff and just having open axle diffs would work more reliably. But going one step further, it would be possible to connect the two drive motors to the two rear wheels one by one for example, with a diff being sandwiched in between them as in the Cat dozer, and then using what would normally be the input of the diff to drive the front axle diff as well. That way the rear axle could not slip, but would still have a diff, and the front axle would be open. It would simplify the whole drivetrain and free up space for other stuff, though probably there's not enough space to put the motors directly next to the wheels, but maybe above the diff with some gearing.. Just an idea.

Thanks a lot, glad you like this one! :)

Thanks, hope you liked it :) Indeed, it's the same gearbox, but I managed to cram it into a chassis with front live axle, which I hadn't thought would be possible at this size in the beginning. In the IFS buggy it was easier. Thank you, well the speed is definitely far from RC models, but as a rock crawler it's okay. Only a bit faster than the Zetros at low gear, but high gear is much better when on flat surface :) Glad you like it and appreciate the writeup. Indeed, the removability of the body limits and complicates things quite a bit, but it's great to have when you need to tinker with the chassis / clean it..

Cool little build, nice functions at this scale, I like the linkage for the bucket. The only thing that's a bit weird for me is the shape of the cab, especially the front of it. Couldn't that be done with a (more) straight face, more like the original? I know there's not so much space for that, but maybe with some long system slopes? Though I guess you are trying to avoid using such things..

Great little one again, looks cool and has nice amount of functionality! Doesn't even look overcrowded, I thought this much functions would make it more dense!

Wow, I like this version, it could be a great candidate for a mix of large and medium tractor tires

Thanks, that's great :) There's plenty of other stuff to build from them as well, so you shouldn't regret it!

Yes, but in that case there was no need for an extra expensive part just for that. The motor and the gearbox was already there. They only had to decide which function to drive with it.

Indeed, let's dream on :) I think the weakest point of those double joints are the heads, and not the axles, so they will be able to handle the same torque as the existing small CV joints. And there are plenty of RC cars with such joints out there, so it should be okay for certain types of builds. That means not too big and heavy ones, but smaller and lighter street cars and off-roaders, that are geared faster, so not too much torque on the drivetrain. And I think the Audi RS will be such, it should be a medium scale, lighter and faster one. So it could work.

Well in that set it did make sense, it was rotating the entire rig, so it was more authentic and had more play value. Even then, it consumed a lot of space. And those were different times, then they wanted to make technic sets function rich, and build everything possible :) In the other thread dedicated to this set, there's some speculation about about a possible pneumatic rotator used for the claw as well. In that (less likely) case of a new part being introduced, using it on the seat as well would make some sense to provide more pieces of a new part in the same set. But that would sound just too good.

Thanks a lot, glad you like it! I agree on the simplicity of the stickers, the first version was more photo-realistic but more overcrowded, so we simplified it :) And glad you appreciate the chassis design and the proper geometry, that's always important for me. Sure, it would be nice to have more options in this scale, let's see what this year brings :)

The pneumatically rotating seat sounds quite counterintuitive, especially if we consider that they are trying to make every set cheaper. Why would they waste a pneumatic cylinder on such a function? Does it have some authenticity? Add any play value? I don't think so. I'd rather bet on marketing people screwing up that sentence, either not knowing what they are talking about or not being able to clearly phrase it. It has happened a few times before.. (like the 'gearbox' of the Zetros, 'diff lock' of the F1 car). Or it got confused during translation.

Ah, okay, now I get it, I thought it's actually the part's number, didn't know it has a separate set/part number that way. Thanks!

I don't really get your argument about this one, or we use the words differently. What do you mean by PU "sets"? For me a PU set is something like the Zetros (set number 42129) or the Xtreme Off-Roader (set number 42099). And when piece count is 1, that's what I'd call a part. And the product number is close to other parts, as I've shown above. I think the small angular motor would even be too large for the box. I have also bought a small angular motor (Spike Essential) separately from a vendor of educational products, and it came in a small official looking lego box (with logo and product number), slightly larger than the motor itself, which is 3x4x5 studs (~24x32x40mm). So that's much smaller. It can't even be a motorization set of multiple motors if the piece count is 1. Also what's strange is that it's almost rectangular. But maybe we're speculating too much here.. That's also how I tend to interpret it.

Interesting! I just checked a few items, and the numbers before that are assigned to PU motors and hubs. Specifically 88017 and 88018 are the angular XL and L motors respectively. So hopefully it's something related to PU. But the sizes indeed don't make sense for a motor, not even a hub, it's something like 10 x 11 x 6.5 studs. Maybe a Remote Controller :))))))))) Nah, it can't be.. Just speculating.. But great that the release date is not that far. @barberminged what makes you think this is a set and not a part?