gyenesvi

Thanks a lot, glad to hear you see it that way!

Hey Guys, I'm back with my second alternate model of the Zetros set (42129). As you might remember from the presentation of my Unimog alternate, I was originally entertaining the thought of rebuilding the Zetros into a Jeep, but I passed since Tim has already built one. However, as I kept thinking of how I would do it, it became clear that I had quite different ideas in mind, and it was just too tempting to do it, so I gave it a go. Here I will write down the design process as that seemed to be something interesting for you guys in case of the Unimog as well, and I also prefer such presentations. Features - 3-link floating axle suspension with Panhard rod at the front - simplified rear floating axle suspension with 2 links of limited degrees of freedom and a Panhard rod - 2-speed gearbox with coupled RWD/AWD selector (hi gear is RWD, lo gear is AWD) - smooth and highly colour consistent bodywork - openable doors, bonnet and trunk - detachable hardtop - detailed interior with green accents, built seats - detailed engine, snorkel, minor extras (roof rack, jerry can, fire extinguishers) Here's a real 2-door model in dark grey color which I used as a visual reference: I also used a blue print to roughly set the proportions in a 1:10 scale. Bodywork Interestingly, this model started out from the bodywork, which I don't do often. As a fan of Jeeps, I have long been wondering what the best ways are for replicating its characteristic details, such as the hood and the grill with Lego parts. My Willys Jeep (alternate of the Defender) uses system parts for the (flat) hood and a simple vertical grill, but I wanted to build one with technic panels as well, replicating the slanted surfaces. I have seen two major techniques, one with the long wing-shaped panels (such as the models of @Madoca 1977 and @rm8), and the other with the long curved panel, mainly the classic model of @Sheepo. Since this set has those curved panels in DBG, and the wheels are about the same size as on Sheepo's model, I was wondering if a similar front could be built from the set, especially the angled placement of the curved part, along with the downward slanting of the whole hood, which also needed to be openable. It turned out that with quite a few alterations here and there, the hood could be built, and even better, they could be built using a few large panels only, which makes it look more clean and uniform.. Some arches needed to be redesigned, and the whole became 2 studs narrower, but the proportions worked fine. Then I moved on to the front and the grill, where much more redesign was needed due to different parts available, but after a few iterations with increasing the width and height of the vertical 'bars', I found the one that fit nicely with the smaller lights in the set and the newer curved small panel extenders (and as far as I can tell, newer Jeeps has such bigger grill, so it seemed fine). From there, I moved on to the sides. I knew it was critical to use the BDG panels carefully, because otherwise there would not be enough DBG beams to build the whole body, and I wanted a clean and colour consistent body. I quickly concluded that the doors can easily be built with the large panels, and the windows can also be built with the DBG connectors. The next critical point was to use the thinner long DBG panels in the rear part above the fenders. The difficulty was that they only left one possibility to mount the pieces of the fenders, so I had to use all those black angled beams there, and I had to build the fenders a bit wider so that I can actually connect the two ends to make it a stable piece. Fortunately, the wider fenders also made it possible to build the front ones from black beams at the same angle, even without more available angled beams using triangulation. The last critical piece was to use the small BDG panels in front of the doors, which just fit there tight. If I had to build that section from beams (as I started out), it would have cost too many beams and connecting them to the chassis would have been difficult as well, but the panel solved both problems (unfortunately, it has a drawback as well, which I will cover later). The remaining DBG panels were used in the back, also allowing for an opening trunk. The last tricky part was the rear corners with the lights. I wanted to make them more rounded with the curved panel extenders, but they would have screwed up the proportions, so I just used a slightly curved system brick to give it some curvature. Also I managed to use the black arched beams to replicate the characteristic rear roll bars, and the black tubular parts to build the roll cage, along with the 15L flip-flop beams, which proved to be critical for mounting the roof. The many flat black panels of the set were enough to build the whole roof, along with the side windows in a way that the whole hardtop is detachable from the roll cage as a single piece. Later, when it was more clear what parts remain, I also added the two bumpers, and even a nice snorkel and minimalistic roof racks were doable to give it more interesting details. Gearbox After being satisfied with the rough bodywork, I started designing the functional parts, which I also wanted to put emphasis on, since that's what technic is all about. However, since my Unimog alternate was about the suspension, this time I wanted to focus more on the RC gearbox and build a less articulated suspension which takes less space. I have been tinkering with the idea of a coupled 2-speed gearbox and a central diff-lock for a while (and @Pattspatt also teased me about it), but I never managed to design a compact one, where the drive motors are also placed conveniently. When I looked up a Jeep Wrangler drivetrain, I found this image, which was particularly interesting for me because of the front wheel drive that can be decoupled. Being offset to the side, I thought this could actually be nicely reproduced with lego clutch gears (something similar I already did with my Willys Jeep alternate, not knowing that it's done similarly in real life). After a lot of juggling with the placement of the motors and the gearbox components, I came up with this quite compact drivetrain setup with the gearbox inside the 11x7 frames, which not only includes the drive motors, but the steering motor too (later on that as well). The key ideas regarding the overall chassis structure are the following. First, I use a simplified (limited degrees of freedom) rear suspension, which requires only one CV joint, which makes the rear part of the drivetrain shorter, making more space for the gearbox, which is placed a bit to the back. Second, I placed the motors to the front of the middle section, and use the back of the motors as the mounting point for the front lower suspension links. Thus, the motors play a major structural role in the chassis. Here is the central part: And here is the whole drivetrain without the motors and the frames: As you can see, the rear part is short, and the front is offset to the side, and can just be routed between the drive motors, under the steering motor. Another interesting thing about it, is that it actually has two shafts (yellow axles at the front) coming from the two drive motors (but they are coupled by the red gear in the middle), and one of the shafts powers the 2-speed gearbox, that then goes to the rear axle, and the other shaft powers the the front axle, so the front axle drive does not pass through the gearbox, as it's only active in low gear. The orange selector switches both the gearbox and the RWD/AWD switch at the same time, activating the front of the drive train when low gear is selected. As with my Unimog, the placement of the gearbox motor was again difficult, as a lot of additional elements (end stoppers, clutch gear protection, down-gearing) need to be placed, so the gearbox motor had to be routed out to the trunk. Suspension As I outlined above, the rear suspension is a somewhat simplified live axle. I saw this trick first in @nico71's Ford F150 alternate, but builds of @rm8 use it as well. It is like a ball-joint based suspension, but without the ball-joint as support that prevents the axle from rotating forward/backward. In case of non-motorized models or smaller RC ones with less powerful motors, the joint itself is enough to keep the axle from rotating, but it was not enough in this case (the coupled motors could just rip apart the driveshaft), so I had to fix it explicitly. I opted for a suspension link that does not let the axle rotate forward on the far end, only tilt sideways (not using towball pins, just regular axles). This setup provides strong enough support to prevent the torque from ripping the driveshaft apart. A Panhard rod further stabilizes the axle to prevent sideways movement. Unfortunately, it's still not as solid as a ball-joint would be, and does not relieve all friction from the driveshaft. On the front, I used a similar 3-link suspension as the Unimog, but I had to move the Panhard rod behind the axle as the space was even less in the front, and managed to move the springs further in, giving it a softer and longer travel. It actually came out too articulated and had to be limited, as the wheels hit the fenders. Also, I used a better steering geometry than the Unimog (no anti-Ackermann geometry), and the max steering angle became very good, too good actually, as the wheels hit the bodywork at max angle, and can get stuck in it, so I limited the angle a bit, but is still better than the Zetros (the limiters are just half pins, which can be taken out to get a lot of steering angle, at the cost of risking the front wheel getting stuck in the body at max angle and max articulation, but work pretty good on flat surface). So the suspension is not bad actually, limited a bit by the bodywork, but the model still drives around quite okay on real terrain. Also, I wanted to experiment with a different steering setup, not placing the steering motor onto the axle. As said above, I found it a nice place between the drive motors, and using the CV joints there was just enough space to route it to the axle. It works okay, however, the two joints already introduce some lag in the steering, which is most noticeable when trying to automatically return to center, it does not center totally. But it's still okay and can be controlled with fine adjustments. Interior As the seats in the Zetros set were too small for this scale I needed to build bigger ones. Since I did not want to use the green beams on the outside, I used them as accents on the inside, they were enough to build seats and to be used in the middle console. I entertained the idea of making the steering wheel functional, since the steering motor is not on the axle, but there was not enough space to route it to the steering wheel, and furthermore, the curved panels used as a dashboard just block the way, and otherwise they are important structural elements that hold the front and the sides, so I did not want to alter them. The battery is placed between the B columns, as there was no other convenient place, and there it's easily accessible. The seats can be folded forward, to give room for replacing the batteries. The engine details are just some imaginary ones built from the remaining parts (nothing working). But the snorkel tubing continues on the inside :) Here is the whole chassis with the interior: And here are a few more renders and photos of the complete model, but much more is available on Bricksafe. Building instructions are available on Rebrickable. Let me know how you like it! Cheers, Viktor

I think at least the looks of it will be pretty close to this one..

This! This thing is huge and way too specific for one narrow category of products.

Hello Eurobrickers, The time has finally come for me to post a model that I have been wanting to build for a long time: RC Jeep Wrangler in 1:13 scale. This is a special one for me because I like Wranglers a lot, and also because the builds and videos of @Madoca 1977 and @rm8 had a major impact on getting me back to Lego Technic. Ever since I saw those videos, I knew I wanted to build my version of the Wrangler. So this is also kind of a tribute to them. Also, there is a third very good Wrangler variant from @ArsMan064, which is actually more accurately scaled than the others, and my version is more like that one in terms of scaling. On the other hand, I wanted my version to be different for a couple reasons. Time has passed since those models, and the lego electronics has changed, so I definitely wanted to build a Powered Up version, which has its own challenges. Also, I wanted to use my own chassis design, and I wanted to change quite a few details on the exterior as well. So this model is the result of all that. To start off, here's an action video: Features all wheel drive with 2L motors, good speed / torque ratio steering by L motor via linkage powered by Technic hub, hidden in the back live axle suspension on both axles, good articulation configurable: easily removable top, doors and rollbar clean exterior and interior openable doors and hood manual winch Design challenges The design of this model has taken a long time and many lessons learned from my previous models. I believe the Wrangler is hard to build in a good scale and in a clean way, mainly because the nose is short and low, so there is little space to work with. Another difficulty is that if one wants a good looking open configuration (which is popular in reality), then the electronics must be hidden well in the chassis, so that reduces the space even further. The original build of Madoca uses a few tricks to mitigate the problem with the nose. On one hand his body is lifted to accommodate the extreme suspension flex, which gives more space under the hood. Furthermore, the nose is one stud longer and the front axle is one stud more to the front than would be accurate when scaled to the wheel size (In this regard, the version of ArsMan is most precise; lower, shorter nose). Furthermore all previous versions route the chassis rail to the front bumper through the bottom of the front face, which prohibits building a completely shaped front face. As the shape of the front face is very characteristic of the Wrangler, I definitely wanted to build it cleanly, but that meant even more space is required for running the chassis rail under it. That left really little space for the front axle, so little that it became impossible to link the steering in front of the axle, so it had to go behind it, which meant that the steering servo had to go further back. And that detail basically defines the whole chassis structure. Chassis structure So it all started off with the design of the front axle, as usual :) I am using a fairly simple one with the steering linkage behind the axle, but that meant that the springs can go either in the center of the axle, or in front. Well, as detailed above, there was not enough space for it in front, so I made a design that has the spring in the center, which required mounting the wheel hub in a bit of unorthodox way, but it works surprisingly well! A dedicated L shaped connector (like this part without one side of the T shape) could be useful here though (and in many other places, I find). Anyways, the axle has attachment points for 4 links plus a panhard rod. Given this front axle, I built a chassis with the steering motor in the middle, protruding a bit into the middle console, and the two drive motors under the seats. The rear suspension is built with the usual positive caster and uses only two links and a panhard rod, with the springs lowered behind it. This was also a crucial point, because of the Technic hub. This large hub can only be positioned above low the rear axle in a way to avoid taking up too much space in the interior, and the springs also need to go around it. Here is the complete chassis, it is quite dense with electronics, they are also structural elements. However, I think it turned out structurally quite clean and light weight, and the axles have quite a good amount of flex and are responsive. Interior I really like the look of Jeeps without the roof and doors, with just a rollbar or even without that. So I wanted to have the interior as clean as possible. Obviously, as the big Technic hub takes the space in the back, that's as good as it can get (and the cables do clutter the looks), but at least the front seats and the area in between and in front remained clean. Luckily, much of the steering motor is covered by the dashboard, and I built the middle console such that it allows the motor to blend in. The drive motors serve as the floor, gears hidden under the seats. I made brick built seats because I wanted to shape them nicely, and also bricks gave me some color options that technic parts would have not allowed. Bodywork There's a simple reason why I built this Jeep is in orange. The key piece to build the front grille in a nice way only exists in black and orange (which is a pity). And as I wanted to have the front built nicely, I had not much choice. Furthermore, I wanted to capture the curved shape of the face, so I had to resort to a brick built solution there. It took a lot of fiddling to let the curvature continue smoothly to the side of the hood, but I am pretty satisfied with the result there. On the top of the hood, Madoca used a few tiles and long panels, which is a neat idea, but I did not like the clutter it took to connect the tiles to the technic pieces, so I used more system pieces for the connection, and turned it into a bulge, which also gives it a bit of texture and opportunity to use a different color, and the border between the brick built and the technic parts became quite smooth I think. The hood hinge point had to be carefully positioned (raised and moved forward a bit) in order to let the hood open without getting blocked (it's not completely smooth though, but good enough). I also made sure the front fenders blend nicely with the tapered nose and the face. Another area I wanted to build differently is the sides / doors. Technic doors are notoriously hard to build nicely (without cluttered look) because of the lack of panels (or even beams) in more sizes, and also it's hard to build the hinge line cleanly (and make the door removable). Here, I experimented with vertical beam stacking instead of horizontal for the sides around the fenders, which turned out quite clean I think. Besides the door itself, the window frame is also a difficult one, and on many models it is unfinished at the front of the door near the mirrors, because it is hard to arrive there at the right position / angle, while also allowing the door to open. That part also took quite some fiddling to get right, but I stumbled on a quite simple solution that even let me fix the mirror in a good position. The point where the side and front windows meet seems tight, but the doors open smoothly without getting blocked. The rollbar is another area I set out to beautify. I wanted to make it slim, tubular looking and uniform, removable, while at the same time properly connected to the chassis and the windshield, and also allowing the top to be connected. Those posable angled connectors came very handy, I think they look better than regular angled connectors, wish they were used more in official sets. Finally, the top follows mainly the shaping of the Madoca version, while I tried to smooth it out as much as possible reducing clutter to the minimum. The top only connects to the rollbar, other than that it only sits on the bodywork, but this way the meeting of the main body and the side of the top / rear window is quite smooth. The rear window can actually be opened if the spare wheel is off. I tried to make the spare wheel foldable, but that made its connection weak, which would have always unfolded during play, so I just simply fixed it. Also, I could not make the tailgate openable, because that's what holds the curved parts on the rear, and the tail lights would have also been in the way, which I definitely wanted to capture nicely. Finally, I added an optional mini winch and a bullbar (which actually uses a flex axle, but could not get that work in Studio, so I used a flexible hose here). Here are some photos of the real build. It's perfect scale for the technic guy :) More renders and photos are available on Bricksafe. Building instructions are available on Rebrickable. Let me know how you like it! Cheers, Viktor PS: a final note about RC control. The development of Pybricks that allows the use of an Xbox controller came recently and I have tested it with this model. I made a program that allows very precise slow speed control (after speed calibration) using the speed servo mode of motors, and also the steering is very smooth; great play experience. Unfortunately at the time of recoding the video I did not have that yet, it would have come handy in some places for precise maneuvers. In the video, I often go much slower than would be possible (it has good amount of torque) just to avoid sudden jumps. I became extra careful after the model accidentally ran off a cliff on the first test day, fell 5 meters and broke into pieces in the middle of a bush.. that hurt.

Thank you guys for all the positive feedback! Thanks for getting back, all good now. Thanks, really honored to hear that :) Thank you very much for the kind words, I really appreciate it!

And what would that contraption be useful for? I guess you can always find a usage that requires a specific part, sure. But I guess probably it would be easier to find more uses for a pinhole with 2L axle. If we call a connection that connects two things in whatever way a basic connection (most existing connectors are like that), then the next logical class off connectors is one that merges two basic connectors into one. And in this case, that would be one unit longer axle or pin on the pinhole.

Thanks, glad to hear that :) Oh I wanted to respond to this as well, but I forgot. Do you mean the thickness of it, or some other proportions? I do agree that one stud of thickness together with the window frame is a bit too much, but that's what you can do with technic parts if you want to build both the door/window frame and the top separately and in a removable way. But I think that the accidental fact that the windshield arrives to a half stud lower point helps it a bit, kind of rounds it off at the front meeting point, and also looks kind of realistic when the top is off that the rollbar is a half stud lower. Btw, I never saw any model that could solve this problem in a better way, but let me know if anyone knows of any. @Milan, I don't actually see this on the front page. Or is it only scheduled?

I do sometimes (frequently) find myself in need for a pinhole with a 2L axle or a 2L pin. But not so much a 3L axle yet.. So probably better than nothig, but not as good as if things were systematic and progressing in proper steps. I wonder though if these are only templates, and the actual patents cover a family of parts in different sizes, instead of just exactly one size. Patents tend to be as generic as possible. The 3x13 frame does definitely seem useful for smaller models where the 3x19 is too long to fit. The diagonal thing is also interesting, but seems large at first sight.

Nice Jeep, glad to see you could make use of my bodywork design :) Looks good in yellow. I also plan to make an update on it once in the future without part restrictions. That multiple steerig mode feature on the FlySky transmitter is neat, I have that too, a GT5, but haven’t had a chance to test it yet. Maybe when I get to build my first model with custom electronics and GeekServos.. I like how you put the electronics under the hood, great idea! And that video with all the fresh snow looks cool too!

Why do you wish that, what’s wrong with Rebrickable?

Hi Folks! Let me share my latest alternate build, a Polaris RZR buggy built from the Audi RS Q e-tron (set 42160). As usual, I was trying to build an off-roader that is somewhat technically different from the A model, and improves things where I found it necessary. Although the set does not have too many interesting suspension/drivetrain parts (and is also lacking connectors quite a bit), the suspension can be somewhat varied. The model was mainly inspired by the following real world counterpart, a Polaris RZR Turbo S, although it has many variants with some differences in the looks (such as the side being closed in some models). These buggies have trailing arm rear suspension with radius arms, something I have never seen built in lego form, so I was trying to replicate that, and the new hubs just gave a nice possibility for it. Besides that, the Audi is heavily missing all interior, so I decided to try and build something with full interior :) I believe the root of this problem is the difficulty of the electronics placement in the Audi, most prominently that of the (screwed) hub, so I had to build the chassis accordingly, which this model nicely allowed. I think my alternate model is the first one that does not have any electronics in the cockpit.. Features independent front suspension independent trailing arm rear suspension with radius arms efficient drivetrain with coupled motors complete and clean interior with two seats, dashboard, steering yoke and middle console lightweight body Drivetrain In order to maximize performance, I definitely wanted to couple the two drive motors. It is a very easy to lay out the motors that way, but since with coupled motors the drivetrain must pass through the middle of the chassis, then the battery cannot be placed in the middle. It cannot even be placed above the driveshaft, because then either the lid or the button cannot be accessed (or neither, if the model has an interior). So the hub must go somewhere else, well, the candidates locations are in the back. I ended up placing it upside down in the back, to allow access to the screws, and the turn on button can be pushed through a lever. That leaves the drive motors to be placed on the floor. Steering As for the steering motor, I also wanted to put it into the front, not interfering with the cockpit. That's also a bit more difficult if you want your steering to be linked both in front and behind the axle, as in the Audi. I think the Audi has dual steering linkage because it needs it due to its screwed up steering geometry; because of those red connectors on the steering hubs to which the links are connected, the links are mounted half a stud higher than should be, and that would cause significant toe in/out and bump steer; so they solved it by making the linkage symmetric, pushing the wheel hubs in both directions. Actually that half a stud matters more than I thought, the links are quite tight, and are under some stress. Not sure how Lego allows such bad practise, though I can imagine they might even say it is intentional to allow less slack in the linkage. Well, a tight linkage becomes useless if they add a gearing after the steering motor (as in the Audi), and you control the whole thing with the touch screen; it will be unprecise anyway, so the tightness of the linkage does not matter much. It would have been much cleaner if they just designed a proper steering hub with the steering arm in the middle, as in case of the planetary one. Then the whole half stud offsetting could have been easily avoided.. Anyways, I decided I don't want wrong steering geometry (even with the dual linkage, it did have some bump steer, I guess because only one rack is driven by the steering motor), so I just flipped the hubs upside down to allow proper geometry (no half stud offset vertically). Here's the complete driveline and steering geometry. It works like a charm, no toe in/out bump or steer, and it has little slack. Suspension The front suspension is a simple independent one with double wishbones, similar construction to that of the Audi. However, the rear one is a trailing arm with radius arms. This seems very similar to an independent one with double wishbones, especially because here I could only implement some of the radius arms with the wishbones. The main difference is that the springs are attached to the trailing arm itself instead of the wishbones. Also, I believe in real life, the trailing arm is the main load bearing structure, and the radius arms only help stabilize the wheel sideways (whereas here it's the other way around). Furthermore, I believe that in real life, the trailing arm and the wheel hub is one solid unit without a pivot. However, in this lego model, I could only imitate this with a pivot at the wheel hub end of the trailing arm. If there was no pivot, then the wheel hub would move non-parallel to the ground as the suspension is working, and then the radius arms would need bal joints on both ends to be able to follow its movement, which I could not implement here due to parts availibility (maybe would be possible with more links). Nonetheless, this simple setup nicely approximates the real thing, and is a somewhat novel suspension technique in lego I believe. It would be nice to understand better how it works in reality, so if anyone understands this better, let me know in the comments. One thing I don't quite understand is that the radius arms introduce sideways movement of the wheel as it moves vertically, and I don't get if there's a trick to make the trailing arm follow that sideways movement, such as being placed at a slight outward angle.. Interior Many people complain about the Audi lacking any interior. I think the reason is a mix of two things; cost saving, and the inability to place the electronics outside of the cockpit (due to the screwed hub). So I decided to make a full interior just to show it's doable even with the mighty screwed hub and only using the Audi parts :) Besides the two seats and dashboard, I added a middle console with a gear stick and built a steering yoke. Bodywork With the bodywork I simply tried to roughly replicate the lines of some variation of the real buggy, for which the many panels proved useful (especially the roof is a nice match). I definitely wanted to reuse the stickered curved panel with the front lights, and because of that the nose came out a bit blocky, so that's a compromise. Also, the nose is about a stud too long anyway due to space requirements for the front axle and the steering mechanism. But otherwise, the shape is quite okay I think. Here are some more renders and photos. More renders and photos are available on my Bricksafe. Building instructions are available on Rebrickable. Let me know how you like it! Cheers, Viktor

That must be a pretty small receiver then! Is that some technological novelty? Would that mean connecting the receiver through a cable, or is it a more direct connection, something like in RCBrick on the bottom? That's kind of an interesting solution, though not sure how many receivers it is compatible with. That sounds good, you mean it would be shorter because of the removed receiver? Interesting to know, I'll test that!

Thanks a lot! Thank you guys! These are the hinge parts: https://www.bricklink.com/v2/catalog/catalogitem.page?P=53923#T=S&O={"iconly":0} https://www.bricklink.com/v2/catalog/catalogitem.page?P=57360#T=S&O={"iconly":0} There's also an older version of them with slide slots, which are not so nice I think because you can see the axle color (often red) through it. Thanks, well the original idea is not mine, probably from Madoca. I just saw the opportunity to make it in orange instead of black, which I think does make a big difference in terms of how complete the face is. Thank you! Well actually I was aiming a bit for the more classic look. The modern version is a bit more rounded here and there (for example the face is not straight but bent), which is kind of impossible to recreate in lego. So I'm okay with the retro vibe. Besides, my other option was LBG, which I felt a bit dull. Silver could be nice, but pretty expensive. Black could have been good, but does not exist, though I'm sure I have seen it on some MOCs.. Thanks! Well I am not yet sure if it will survive until the Buwizz camp, because I might need the motors from it to build my entries.. Will see, but I might keep it a bit longer than other models :)

The receiver looks like this, and is 11 x 25 mm size. How does that compare to the one in RC Deck? One thing about the bind button, I am guessing that binding might need to done more often than one would think, for example if the transmitter is used with other models or one buys two RC decks. I guess then it will always need to be rebound to the one being used. So you might be useful to have that button on the outside, though not sure how that could be done. The split cable is interesting, so then no stacking is needed, but one FP plug still needs to handle the amps of two motors. Maybe it can better do so when they are not stacked though. Thanks for the info on the battery!

Looks nice! Is the receiver on the PCB or is it separate? Any chance that I can swap that out to a FLySky by re-soldering wires? I just bought a small 4-channel FlySky receiver and works nicely with my transmitter. (In general, what's on the PCB and what's separate, if you are okay with sharing such things?) How did you power 4 buggy motors? Did you stack two plugs on one port for that? Didn't that ever melt the plugs for you? Some people reported such things. What's the electronics right where the battery is connected? That seems to take up quite some space, and next to it there seems to be quite a bit of empty space. Do you have a link to the batteries you are using? I mostly find 3s LiPos with larger connectors, like XT 30/60, and often only 2s comes with JST (I guess you are using 3s).

Quite a bit harder, I'd say more than double; just compared squeezing 2 of the yellow ones vs a big blue one, and still the blue one feels harder to me.

The solution I meant has a similar range of motion than the above solution, and is also similar to that of @Stereo An example is here: and more details are in this thread: But yeah, I also thought about those 1x1 bricks with axle holes but thought they would be too edgy and get stuck. Interesting to know that it actually works okay.

Those aren't really solving any problem that was not solvable before as they require the same amount of space. They are just not small enough. Plus are unrealistic and have more friction. Thanks TLG. It does get you a slightly better firing order, but not too much. Plus this problem. I wish instead of the Kawasaki pistons, TLG produced something more generic and useful, like a 1.5L crankshaft piece (1.5L liftarm with 2 axle holes), or a 2L axle with stop. Both could have helped here and would have been useful for other purposes as well.. On a more constructive note, @Divitis have you seen crankshaft designs that use rotated 1x1 plates with a bar through them? And the pistons could be half pins with tiles on top, held by half plates. Although that only works up to V10 using a 7L half liftarms to hold 5 of them on one side.

Interesting to hear about those copyright issues, can you (or others) explain a bit more in detail? Is it the case that TLG has copyright protection on certain parts only? Which ones, and any ideas why? Has the others already expired? Are parts protected in groups, for example the same type of part in all sizes? Does CaDa also do copyright protection of the innovated parts?

Really nice work, I like how smooth the lines / surfaces are, good usage of larger panels where possible. Even all those stacked beams look nice as they result in little clutter.

On the Pybricks website, the sample place where you can install Pybricks, you can reinstall the original lego firmware. No need to save anything externally. All you need to to is open the Pybricks website in a BT compatible browser, and you can install firmware and load the programs to the hubs from there. Not sure what plug you mean here? Are you talking about external lights or the one inside the hub? For external lights, you need to buy they PU lights from lego.com, and then just plug it into one of the ports. As for the programming, it is easier than you would think. You don't need to learn programming in general. It really is just a few lines of code that you need to gather from the examples. It is all about configuring which ports you use for motors / lights, and then telling what action should happen on which input. And Python is really meant to be an easily readable/understandable high level language for people who don't necessarily have deep programming knowledge, that's why it's ideal for this task. So give it a try :)

These are interesting findings, good to know. So I guess the problem could be that the ESC uses a different PWM frequency than the servo needs. But alternatively it can be tricked by using proportional voltage.

Okay, I see. That's weird then..

But is it an original Lego servo or is it a 3rd party one? Only original Lego ones are capable of proportional turning, none of the 3rd parties.