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Oh, that's right, not the whole model. Not sure if it's possible to share just some ideas / renders about the modification for the steering itself. Maybe you could post some renders about that part here in this thread then for guidance for those who'd like to modify it, this may be a better place for that, and that way your thread is not polluted. Up to you, I'm okay with that. I see, can also work. Did you do down-gearing? Doesn't that take up more space?

I thought it should be doable, and glad to hear you did it, thanks! I guess only the servo replacement is not trivial because of the different shape, the rest (L motors, M motors, maybe even battery) should be relatively simple. Maybe you can share it in your PF mods thread? Or you want to keep that for official models only? Thanks for the support, but I guess it's been a while since this was published.. (almost exactly 3 years now!)

Thanks for all the feedback! Indeed, that is a tradeoff, and I choose the ground clearance :) Glad to hear that there's little damage! I also observed some wear on ball joints, not just on the hubs but also on steering links. Maybe some greasing there could also help.. Thanks a lot, happy to hear that you enjoyed it!

Thanks a lot, glad you like it! Really appreciate this, glad to hear that clean chassis is becoming my signature, I do really strive for it :) Thank you, those old headlights seem to resonate with many people who had sets from that era :) Sure, give those leaf springs a try! I think they are especially great for trucks. Thanks for appreciating!

Oh indeed, I found the 3d rotating video on lego.com too, it's visible there. Weird photo angle.. But the little truck looks cool :)

Looks like an cool little parts pack, what shades of blue are those? The way the front axle is mounted on this one looks weird / asymmetric, even the spacing seems wrong (like it would not fit). Does anyone understand how that is?

Oh thanks for these photos, they look quite nice together :) Indeed, plates with bars and clips are a good alternative for hinge parts that I am starting to discover and use as well!

Thanks! No, the flex axles never fell out, the mounting of the axles is constructed in a way that it follows the arc of the axle as it bends, and I think that is key here (also for soft articulation). Here is a close up render of the leaf springs, at the outer end, they are actually inserted into a (black) axle-pin connector, that creates an L shaped mount, and as that rotates it nicely follows the arc of the flex axle. Thank you!

Nice looking truck! Interesting solution for connecting the spring to the lower towball arms! This small scale has a so much potential :) Yes I know about that heavy duty CV joint technique, I haven't used it yet but plan to test it in the future. Glad you got some inspiration from mine as well!

Hi Folks! Let me show you a build that has been sitting on the shelf for a while but I only got around finalizing its presentation lately: a Zil 130 6x6 trial truck built for the mini truck trial challenge in Buwizz camp 2024. The model is actually a predecessor of my Ford F150 built at the same scale and color. As the rules of the competition said that one can only enter with a proper truck (not a pickup truck), I had to build something new, but as I did not have much time to build, I wanted to reuse some of the chassis/suspension setup, and the small blue fender parts. Because of the blue color, the Zil was a convenient choice. However, I decided to make a 6x6 version for better traction and for the challenge of building a dual rear axle, which I have never done before. Features All wheel drive with independent rear driveshafts, 2x PU L motors 5-link live axle front suspension with coil springs Live axle rear suspension with leaf springs by flex axles and support links Linkage based steering of front wheels by PU L motor Openable doors and removable cargo bed (for more flex in trial) Simple but complete interior Chassis and suspension design When I started out, I knew I wanted to keep the motor layout and front axle design from the Ford F150, but I also knew the rear axle design had to be changed because the coil spring setup was not a good fit for a truck (too high). So keeping the motor layout, I adapted its rear end to a truck, and also removed the gearbox and its motor to give space for the double driveshaft. The bare chassis looks like this, simple and slim: Then I started experimenting with leaf spring setups using flex axles, which have been used by many (I especially like the work of @paave in this area), and looked promising. However, the existing designs I found were not completely satisfactory for my needs; they took up too much space for two axles close to each other, and they were a bit stiff for my lightweight truck (I wanted something with a lot of flex). Typical designs start out with a bent (11L) axle in a downward looking quarter circle, and then the axle bends upwards upon articulation, which gives a preload to the flex axles. I found a configuration which starts out with the flex axles flat and then bends them upwards upon articulation, which allows using shorter (7L) axles with a tighter mounting, while still having a soft flex. The rear axles are really slim, consisting of only a main beam and wheel mounts. They look like this installed into the chassis: To keep the rear axles in position, a row of lower links run underneath, and and towball arms secure it from the top. The two rear axles can articulate completely independently, the are not coupled. I am really satisfied with how this came out, it's very compact and even looks somewhat realistic. Bodywork and interior To build the body, I used a mix of technic and system parts. The blue fender pieces are quite a good fit for the Zil, and a few curved slopes around it can fill the holes. The micro panels add nice curvature to the doors, and further sloped system parts can be used for the B pillars and of course the hood. Also, I wanted to have a brick built front face / grille, which I also managed to realize with system parts built in various directions. In general, the technic micro panels and curved system slopes play very well together, I love to mix them at smaller scale! As for the interior, two small seats are perfect, and I had space to add a dashboard with steering wheel and a gearstick. Running the cables through the cabin was a tough part though.. Furthermore, besides the bare trial version, I wanted to make the model so that it can be a complete truck with a cargo bed, so I made a simple detachable one using a few large panels. A key to this is that the rear section of the chassis is low enough due to the compact suspension. Here are some more renders and photos as well. More pictures are available on Bricksafe, and building instructions are available on Rebrickable. As for the performance of the model, without the cargo bed it is really a cute little agile beast :) The two L motors provide ample power, the suspension has a lot of flex, ground clearance is also quite good for the size. Unfortunately, the turning radius is not so great due to the length and that only the front wheels are steered, which proved to be a disadvantage in the trial competition. Also, the competition allowed for bigger tires (up to 62mm) as well, which I did not max out, but wanted to use these smaller ones instead because they look so cool; that also put me to a disadvantage against other competitors, so I did not place well. But when just playing for fun and making the video, this little truck gave me a lot of joy :) Let me know how you like it! Cheers, Viktor

Really cute build, great shaping, and I love how much mechanics is stuffed in there, that transverse front engine is really neat, I would not have thought that it could fit along with the steering. Clean interior, and the convertible top is also a nice addition. Great work!

Oh, that makes sense then, it's a believable name :)

That's an interesting solution, I haven't thought about that, only problem is that in the incoming end I cannot use a stop axle to secure the small gear because that has to be a heavy duty CV joint in a live axle.. so I'm also afraid of what @keymaker is saying.. This is also a nice trick to improve it, but it mainly protects the large gears, not the small ones. If the incoming axle (without stop) slips out a bit of the 12T gear, then heavy forces can still move it and grind it up I guess.. Yeah, that's stable but the inefficiency part rules it out in heavily motorized stuff :)

Cool one! I thought first it's a Unimog :))) But what's a Mack Marble? I searched for it on Google and primarily found your builds :) but no real trucks in a similar form factor.. What tire size is this using? At first I thought it's Zetros size, but maybe rather 107mm? I guess the smaller DBG one is using Zetros tires?

My assumption is that majority of buyers have no clue what kind of pieces exist, and what pieces are new (just read some posts in FB groups). We are a small minority here who follow the part inventory.

Sure, thanks, I'd appreciate that, standard pins sound simple enough as a start! You mean ditching PF ports? Sure that would be the best but then standard PF motors are not compatible. For not too extreme power (up to 2 buggy motors / XL motors, and up to 4 L motors) this method should work fine though.

I have the opposite problem, does anyone know how to receive response from Buwizz support? :)))) I had a few questions that I sent and were unanswered in the past. This one I sent lately and no response, so I ask it here as well maybe someone has experience with this. It's about control of PU motors in the Buwizz 3 protocol. I can see that there's a separate command (0x31) for advanced control of PU motors and that the interpretation of values depends on port state. I can also see that command 0x50 is used to set the port functions, and that some default values are selected for known PU motors when switching between PU servo modes. I guess those are the PID parameter values listed in the section "PID controller structure"? I also see that there's a command (0x52) to set the servo reference input (speed and position, depending on port mode). What does that reference input mean exactly? I guess for position servo, it sets the reference value to the current motor position, so that the current position becomes 0, is that right? But most importantly, I'd be interested in speed servo control. What does the reference value mean in this case? I guess the speed servo function needs a reference to know what the max possible speed is, and all other values are interpreted with respect to that? So how can I set up speed control to work properly? What value should I put there? Do I need to run the motors at max speed (inside my model under load) and set that speed to a certain value, which will mean 100% for my model, and all other values to command 0x31 will be intepreted with respect to that? Or did I get it wrong and the setup process should be something different? Another question is whether this function is available in the Buwizz App? I haven't found anything related. Precise slow speed control would be very useful functionality for the truck trial competition in the Buwizz camp in 2025. Is it possible to add it until then?

Speaking about PCB design, I have been looking into just that recently, and I was wondering how you made the PF connection in your RC deck. I remember seeing an image somewhere in this thread about the 'pins' going from the PCB into the PF connector, but I can't find it any more. Can you show that part? Did you use some 'standard' electronic part like a pin / pin header, or was it some custom flat bent metal part?

I get what you mean, but why do you think Lego started making separate spur gears and smooth running conical ones? Because they realized that they do need that performance (less friction) after all. Double bevel gears are strange for me for another reason as well. In my experience it's very rare to use both sides of it in a double-mesh, however it is really common that the unused side causes friction with a beam next to it. So they were basically opting for a rare case while not bothering with the frequent disadvantages. That feels counterintuitive. Thicker single-bevel variants with a smooth other side could have been better. But it's not always about performance. Sometimes a part wants to fulfill two distinct functions. Consider this recent one for example (or its 5x2 counterpart): It wants to be both a curved panel section and a 2x3 L shaped liftarm at the same time (on lego.com it is categorized in "beams with shapes"). As a panel, it is more-or-less okay, can join to a similarly curved 7L or 11L panel, but it has an inner corner with the cross-hole, unlike its long counterparts, which can be in the way (though can be useful for mounting in other cases). However, as an L shaped liftarm, it is often not usable, because the curve is in the way in most dense builds, exactly when a 2x3 L shape would be required (in not so dense builds, often a 2x4 or 3x3 L shape can be used instead). What is worse, is that I'd predict, that the existence of this part will block the introduction of a proper 2x3 L shape for quite some time. Sad, because it would be a very basic, very useful part.

Interesting, to me, so far, this sounds like the most probable explanation of why all clone servos have only 3 positions; they all copied the hardware, but they could not really match the microcontroller software to it.

Actually I forgot about those old gears, I think they are closer to real conical gears than the single bevel gears, which are also kind of an approximation for conical ones. Also, the new gears in the Audi diff. And then the old crown gear is just that, a crown gear :) And year, I guess a double bevel gear is just a mix of conical and spur gears to allow more possibilities. However, something that's good for many things, is not really good for anything; double bevels have more friction than necessary in both configurations, and Lego is starting to realize that, and now making separate spur and conical gears (Audi). I hope this trend continues, including other types of parts (for example, currently there's not good way of making a heavy duty smooth 90 degree 1:1 gear mesh in a 3x3 space). There are so many parts that try to be multiple things, but in the end are not great for any of the options, and eventually need to be replaced by a proper part. It would be better on the long run just to have parts that are good for one clear purpose without compromising.

Well, if you look up spur gear, it means a gear that has straight teeth, perpendicular to the direction of rotation. So it is not diagonal, and the gear is not cone shaped or beveled, just the most basic one you can imagine. Since in lego there are no diagonal teeth gears or cone shaped ones, only bevel ones, hence in lego a spur gear equals the plain ones that are not bevel gears.

Okay, it may be that the stick is called the selector, and the orange parts are called changeover catch, rotary and fork, respectively. Though the rotary is often called wave selector.. And even in this model, the stick/selector and the shift forks are separate, and the stick moves the forks, as you can see in the assembly video above. Anyways, I guess it's clear which ones I proposed to move to the sides, there's only one gearstick and it would not make much sense to move that one.. When I say fork, I mean the fork shaped one, it's that simple.

I think he meant 8T. And that's just the normal 8T gear that has been around for ages. Not sure what else it could mean, if you look up the definition of a spur gear.

Yes