gyenesvi

Ah, so that's the thinner one, that does clear. What tires do you want to put on them for an offroader? Does the tire also clear?

At this size, not much fundamental improvement is possible if you want to preserve ground clearance. What size of wheels do you use? Did you try using black friction pins instead of the grey frictionless ones to mount the 'wheel hubs' to the cross beam? That's what I did and it worked okay for me, although with a light model. At this scale a model should be small, how did you build it heavy? Is it a big truck? Also, why do you use a 11L beam on the top when the axle is 9 wide? It will collide with the rim, no?

It’s starting to look great, nice progress. Hope you can buy parts for it, I was recently amazed how rare and crazy expensive some things can get..

Yes, I know this and I mean it like that in case of Buwizz as well, the power could mean max allowed power. I know my way of describing it was sloppy, but I only meant to illustrate with examples/ideas that the user could be setting some understandable high level parameters, from which the actual PID parameters could be derived by the FW. No problem. So the issue is that the trans-clear plug has two small (miniature) clips inside it, into which the plug clicks when you insert it, and holds the plug inside. Those small clips broke off.

I think they use that in case they need one with a 3L axle, as the old one only has 2L axle. That I still don't understand. We are still waiting for the reveal of the set that actually warranted its development, because I guess it was not the Daytona. I think we have little hope, because the new CV joint is too big for the normal hub to fit in, it would collide with the vertical pinholes. It would have to be made like the planetary, with integrated towballs, which would limit its usability. But would be great still..

What I am saying is you don't explicitly need to take all those things into account. You only have to know that heavier models need more power for steering, and then you bump up the power percentage value. In general, if your steering is struggling for any reason, you bump up the power value. If it looks too strong and rips your build apart, you decrease the power value. Your steering is making too fast movements and overshoots and adjust itself too much? You decrease the speed value. Your steering is sluggish? You increase the speed value. You should not need to care what caused the wrong behavior, what you need to know is which parameter to adjust and in which direction and what's the order of magnitude you want to change (with the current parameters, we cannot even guess that intuitively). And certainly you don't need to know all the underlying mathematics of the PID controller. People who don't understand the math behind can only think in these intuitive parameters I believe.

He said $160 in the video not 200!!

I don't mean those parameters themselves, but the PID parameters could be derived from those by means of preset values and interpolation for example. Let's say you test a bunch of use cases from small models to large ones, and come up with PID parameters for typical cases, like those small/medium/large presets in the Buwizz app. Then you say large model corresponds to 100% speed/power, medium model to 70% speed/power and small model to 40% speed/power and you interpolate you internal parameters in between. For example when the user sets 80%, you interpolate between your medium and large values for each parameter. Let me know if it's clear what I try to mean. Most LWP commands receive a speed/max power parameter.

Oh wow, all those DBG parts are very welcome.. Finally the 11x3x2 wing panel comes, I've been missing that one.

I think @amorti does have a point here, I'm not satisfied with all those parameters either. From my research/engineering background I know how such scenarios come to existence: the engineers cannot design an algorithm that works reliably for all cases, so they come come up with a parameterizable solution, and allow the users to adjust the parameters. Now some parameters are okay, the problem is when the parameters are too many and hard to interpret. One typical case is when it is not entirely clear what a parameter effects or what its range is. A motor speed/power is easy to understand and set between 0 and 100%. But parameters of a PID controller are not intuitive and their ranges are not well defined (open ended), so putting those into the hards of everyday users is kind of questionable. I would personally prefer if the user could only set simple things like steering power and steering speed that they can easily understand and tune, and the firmware would derive its internal parameters from those. The lego firmware only uses such parameters and they manage with it. For example the user tells the FW by steering speed how responsive steering it wants, and all related parameters can depend on that. Also, by setting steering power, the user basically gives info on how heavy the mode is or how the steering gearing/linkage is, and all related internal parameters could depend on that. Did the team try such approach yet? You mean glue the motor plug into the Buwizz unit? That's like glueing your model together.. :) Not really a reusable solution..

Hmm, same thing happened to me (no child involved), and I think I reported that too. On my Buwizz 3 unit I bought in the camp last year, the first time I inserted a motor plug, one side of a latch broke immediately. Soon the other side broke as well. After a bit of usage, it happened to another port as well. Luckily, the plug has enough friction to stay in there just by itself, so I gave up on fixing it. It's like a 1x2mm piece and it's on the inside of the plug hole, inaccessible :)

That is indeed great news! Thanks! I am personally really interested in this one as well. Is this also an update on the firmware? I reported a BT communication issue two times on the website and also posted it here (the firmware seems to process incoming BT messages too slowly and get overwhelmed resulting in up to few second lags) but I never received any response about it. Is there any chance that that issue was also addressed in the update?

That's great to hear! :))) Excited about next steps! It certainly looks more polished with this printing technology, although I thought even the latest prototype was good enough. After all, it's the electronics inside that matters, and only the cover will be visible on the bottom when inserted into the hub..

No, unfortunately there was not enough support on kickstarter to start mass production. Pity, because it is great to have, I happily use my test unit ever since, and it does make a difference. Besides more power, for example, in my RC Bronco model, the rear axle can use softer springs because of the much lighter battery, which results in more axle articulation and better offroad performance. If there would be visible interest, maybe @Phondly could be convinced to make some units for sale with the current 3d printed case, though when I last spoke with him he said that shortage of electronic components is also a problem nowadays..

I like how this turned out, it looks nice and drives well. Great that diff locks are incorporated!

Thanks, glad you think so, indeed B-modelling can be restrictive, though often it's less restrictive than one would think if the model is well chosen for the available parts :) But true that for really fine builds a wide selection of parts can be required.. Thank you, indeed this is not such extreme build in terms of flex for example, but the goal was to have it more realistic. And I think it becomes quite a bit more difficult if you want to keep motors off the axles and have an actual clean cabin.

Thanks for all the info. While it's great that it seems to be able to power those motors without any problem, the short playtime and the controller is a letdown. With a Buwizz I can usually play for an hour or so without very significant decrease in playability. Thanks, this is what I was interested in, so I did order a few of those micro motors.

I love the final result! The looks are simple and elegant, and it is really interesting mechanically. I never knew exactly how a garbage truck works inside, so thanks for showing it :) I love the two stage compactor, and also the hybrid drivetrain is a very original addition. Great work!

That's promising, at least shows it should be possible to make it work properly with Buwizz as well.. That's a pity. I was thinking more like RC pistol-like controllers maybe as it could be using the same 2.4GHz system. But maybe the communication protocols vary in these systems. That is not possible, as BC2 on a phone works with Bluetooth, not 2.4GHz radio. But the remote controller does not use too much energy so that's not really a problem (I mean if you are using rechargeables and can recharge them like once a week). On the other hand more weight in your hands can be tiring on the long run.

I am checking out the electronics on the Cada website, and I see there's also a 500mAh battery (new version) and buggy motors available. I was wondering if this battery can power two of these buggy motors without shutting down. Does anyone have experience with that? Also, this battery is said to have 2.4GHz radio control. Is it only controllable with the corresponding remote? Is the remote proportional or only on-off? I've heard guessing the servo cannot be controlled precisely. Is that because of the servo itself or the controller? These motors are compatible with PF components, and they also work with a Buwizz, right?

Things are not so simple in a gearbox. Remember, that as you have gears for the different ratios, when the output shaft is spinning through the selected gear, it back-spins all the other gears for other speeds. Now as it back-spins them, that creates an up-gearing in the system. For example if you have one path with 1:1 ratio, and an other with 1:3 down-gearing, when you select the 1:1 path, the other path back-spins 3x faster than your motor output. One thing you might want to consider is that if you make an RC model, you can control the motor in reverse as well, so the reverse speed does not add much playability value, only adds to the realism of the build, which I'd find more interesting for manual models. Indeed, if you want to RC it anyway, that is the simplest way to go, because then you'd probably need an RC switch mechanism as well. I'd say such a 4 speed gearbox would be a good compromise to start with and see how it works out for your model.

I agree that there's no clearly better solution for now, just wondering if this is something risky experimenting with. Yeah, I would not use that solution. I do the same, but still, the sheer speed / power of motors might put wear on those joints I guess. That might help indeed.

Hi Guys! This is a rock bouncer model I built a while back last year for the off-road competition in the Buwizz Camp in 2022 and ended up in 3rd place with it. I have been postponing publishing here as I wanted to make a version with a more realistic livery (stickers) and also make more testing / filming. Well the livery project is also being postponed for various reasons, but finally as the weather is getting better I could finally take it out again for more testing at least, so I decided to make a writeup. But I believe a video tells more than a lot of words, so let's start with that :) So the build is meant to be an accurate model (as much as possible) of Tim Cameron's rock bouncer buggy named Tyrant. Here's a short video showing around the real thing. It's a monster. If you follow rock bouncer races a bit, you might agree that this guy is probably the best builder out there, and his 2022 model is not only very capable, but also a very cool one among these often raw looking hand built rock bouncers. This is one of the reasons I decided to build this one. Another reason is that it has a suspension geometry that was possible to closely mimic in lego form and results in an amazingly smooth responsive and flexible suspension. Rock bouncers are different from rock crawlers in that they don't just crawl up rocks slowly by precise manoeuvring, rather they use sheer power to bounce up the rocks and steep walls. Such a build was definitely calling for the use of Buwizz motors, which I had been wanting to test, and also this way it was an ideal entry for the competition. Another goal with this model was to build something with a really massive and realistic 4-link suspension both front and rear, and buggies are ideal material for that. And one more thing to test was if it is possible to build a sleek tubular body that's also solid at the same time. Features - Long travel, highly articulated, bouncy live axle semi-triangulated 4-link suspension both front and rear - 4-wheel drive, driven by 2 Buwizz motors - Steered by a PU L motor - Powered by a single Buwizz 3 unit - Good weight distribution, low center of gravity, very stable against rolling over - Working V6 engine at the front - Fully tubular exterior with a few side panels, but very sturdy due to inner beam structure - Realistic cockpit with detailed racing seat Suspension I have previously built rear 4-link suspensions on a medium scale, but I was never completely satisfied with the realism of the geometry. There are all sorts of factors in real suspension geometry, but one thing that I realized was that I was never able to position the upper links realistically, so this time I dig into how it's really supposed to be. It turned out that the best geometry varies with the purpose of the vehicle, but in case of these kind of buggies, the upper links usually start out quite low, which makes things quite difficult in terms of avoiding collision with other things. This is especially true for the front, where the links need to go around the whole engine. Other interesting factors are the nature of triangulation and where the shock absorbers are mounted. A setup used in some of these rock bouncers is a semi-triangulated 4-link, meaning that the lower links are parallel, and the upper ones form a wide and pointy triangle. This allows for a shock absorber to be mounted onto the lower link itself at around half of its length, effectively doubling the travel at the end of the link. For this to work, the lower links must be mounted to the body in such a way that the link only tilts minimally (so that it doesn't twist the shock absorber), and there's a lot of tilting at the axle end. This is something really easy to replicate in lego form; the link at the body end is mounted to frictionless pins or axles, while the axle end is mounted on towball pins, resulting in exactly what is done in reality. I also managed to add the imitation of sway bars as on the real buggy, but those are only for aesthetic purpose. Here are renders of both front and rear axles. The rear one has a very long lower link (15L beam with a towball arm on the end). Drivetrain As the model is driven by 2 Buwizz motors, and the form factor of those motors makes them hard to integrate into live axle off-roaders, I had to apply some trickery when building the drivetrain. There were two problems with the motors. First, I wanted to make the drivetrain efficient with minimal gearing to minimize wear on the components, but at the same time I wanted to leave the middle of the model for the cockpit. So the only place to put the motors was in the back behind the seat (which is already quite far back in the real buggy), in a vertical position. The idea was that hard coupling the two motors further in front would make space in the middle for the double CV-joint drivetrain going to the rear axle, which had to be long enough to enable the new 5L sliding male part to be used, necessary to follow the movement of the massive suspension. However, that brings another problem; the two motors cannot be placed close enough for a simple 16T gear-train to hard couple them, only further apart. First I tried 1 stud wider setup, coupling the motors with 24T gears, but those took up too much space. So I ended up experimenting with placing them on a half stud offset and coupling them with 20T gears, and that worked out quite well from a rigidity point of view as well, I was also able to use the motors as structural elements. Besides the basic drivetrain, I later also added a working fake engine with a fan, because there was this big empty space in the front right where the engine is in the real car, so I could not miss that opportunity :) But it's very impractical in a high performance model, and those motors even generated plastic powder inside the pistons! so I ended up disconnecting the drive from it when I was playing the model.. Chassis As I knew I wanted to build the outer body from tubular elements, which would not really going to be holding anything structurally, I wanted to design sort of a back-bone inside the chassis to hold everything together. This is mainly achieved by a couple of beams running through the center of the chassis. The two Buwizz motors are also used to hold the back of the body. Also I had to place the remaining electronics. I did not want to place the steering motor on the front axle to minimize the unsprung weight, so I thought it could go under the seat and steer through two CV joints. As the real buggy has only one seat on the left, I could use the right side to place the Buwizz unit; it is placed very low on the floor giving a quite low center of gravity. This way the whole front section remained empty and available for the fake engine. Here's a render of the inner chassis that serves as the load-bearing structure: A note about the drivetrain: it really requires lubrication to be able to take the abuse without serious damage. I have been using silicone grease, which seems to work so far. Bodywork So as the inner structure of the chassis is rigid, I was able to put a tubular bodywork on it with tubes going in all angles. Obviously, it is impossible to reproduce the rich and dense tube structure of the real buggy, but I tried to mimic the main lines at least. It turned out to be quite complex especially at the front, but I am really satisfied with the end result. Here are renders of the complete chassis with the tubular outer structure on it. On top of the tubular structure, the buggy has minimal paneling on the side, and luckily it was possible to fit a few panels of the right size and shape between those tubes. Unfortunately, the model cannot be built with green panels / wheels as some key parts are missing from the lego lineup. I was able to build it first in orange, that went well with the yellow springs and wheel hubs. It would also be possible in red, and later I built a version in blue using 3rd party parts for the large wing panels on the side as that's the only one missing in blue. I think this colors works really well here. Of course black would also be a viable option, but that did not look so cool on renders. Here are a few more renders and pictures from various angles: More images are available on Bricksafe. Building instructions are available on Rebrickable. Since the race in the Buwizz camp, where other models were visibly faster than mine, I rebuilt the drivetrain with older differentials (as I originally built it with new ones) resulting in a 1.5x speed increase, and it still has plenty of torque to go uphill. Unfortunately, the Buwizz unit is prone to shutting down this way.. I must also note that the model is hard to control with a touchscreen, it is even challenging with a physical controller when going on rough terrain and trying to avoid bumping into things and scratching it all over the place. Although, with an appropriate skid plate (duct tape at the bottom :) ) I worry about that less, and sometimes just give it full throttle, and it really goes through everything that I throw at it, really smoothes out the terrain amazingly. That's really satisfying, I really feel like playing with a real RC car. I'm trying to prepare another video showcasing that, hope it will actually be able to show that aspect nicely. Let me know how you like it! Cheers! Viktor

Looks cool, but I wonder how much those old CV joints wear under the stress of those two Buwizz motors?

Haven’t noticed this before but it looks the same for me, sadly..