Teo LEGO Technic

Thanks guys! I hope it'll be worth your time

Awesome model, I love it! Congrats on the prize. 42055 is indeed a great candidate for C models :p That was all I could find as well. Are you planning to make instructions @BrickbyBrickTechnic ?

Looking great! The solution with the red clutch and clutch gears to transfer two functions through the turntable reminds me of the LEGO 8043 excavator, still one of my favourite sets ;)

Hello EB friends! Today, I'm getting to work on a new project - a 4x4 rock crawler to compete in our upcoming Toronto Truck Trial in August. I've always wanted to try my hand at a rock crawler, but somehow never came around to it until now. It seems like the perfect opportunity to make the best offroad vehicle - faster than a large 6x6 or 8x8 trial truck, but still having excellent offroad capabilities with large ground clearance, huge suspension travel, oversized wheels, and the perfect excuse to omit bodywork entirely and make a light, nimble machine. To make the best rock crawler I can, I'm going to draw inspiration from a couple of my past creations (the parts of them that went well) as well as from some other builders' MOCs. First of all, I'm going to reuse the general axle design I used in my Praga 6x6 Trial Truck, which was inspired by @Attika's design in his offroader: To power this crawler, I want to get the best power-to-weight ratio I can. Since I'm limited to 2 x buggy motors and a BuWizz 2.0 - that's all I've got and I don't plan to invest more money at the moment - the only solution is to keep the truck as lightweight as possible. In my latest RAM pickup truck I was very pleased with the performance it achieved in low gear using 2 buggy motors and planetary hubs. Because I will be using larger crawling tires, I will reduce the ratio further for this build compared to the pickup, using the same 12-tooth bevel gear, 28 tooth bevel gears pairing as in my Praga at the axle, for a ratio of 2.33:1, rather than the ratio with the 20-tooth bevel gear, 28-tooth differential, as on my pickup, which has a ratio of 1.4:1. Overall, because my 3rd party crawler tires have about double the radius of the 62.4 x 20 tires on the pickup, and so double the circumference and double the speed, the ratios will more or less cancel out and the crawler will have the same speed and torque as the pickup, which was plenty. Indeed, it may be a bit faster, but it will also be lighter to account for it. If I got any of that math wrong, please feel free to correct me, but it makes sense to me that the speed is proportional to the wheel circumference and therefore the wheel radius, by the formula 2 * pi * r for circumference. Next, I'm going to just omit differentials entirely. I think the truck should be light enough to not need them, although the grippier tires may slow it down in the corners where diffs are necessary. For the suspension, I want to try my hand at building a four-link triangulated suspension, partly because it looks fun, and partly because it offers the advantage of being able to connect the axle to a small body, that doesnt need to extend all the way over the axle to accomodate a Panhard stabilizer rod. I think I will take inspiration for that from @PunkTacoNYC's awesome Chilli Crawler: In summary, then, here are the current specifications, ideas and goals for this build: 2 x buggy motors mounted in the body for drive, PF servo in the front axle for steering; BuWizz 2.0 for power Lightweight build overall to keep weight minimal and improve power/weight ratio - little to no bodywork, and short wheelbase Triangulated 4-link suspension to enable a smaller, lighter body, using the suspension links on the front axle to create a mild caster angle Planetary hub live axle suspension, as from my Praga truck, inspired by Attika - I just can't think of any way to improve on these, they're so simple, robust, and elegant, and have very precise steering and great ground clearance The first step is to adapt the front axle for this build. I will make it two studs wider to account for the larger tires, and I have to figure out mounting points for the suspension links and shock absorbers. Other than that, I will leave it untouched, as it just has it all. The planetary hubs and bevel gears together create a mechanical reduction of 12.6:1, which is excellent for how compact it is. The hub + defender rim combination keeps the pivot very close to the center of the tire, making the steering more effective. Attika's clever design gives it excellent ground clearance. And, importantly, mounting the servo on the axle gives it excellent precision with return-to-center steering, something rare for a heavy-duty axle, and it is very robust with the double-racked steering mechanism - I can't remember who recommended that to me in the past, but it's brilliant. Here, then, is the beginning of the front axle, widened by 2 studs: I'm excited for this build - I think it's going to have some nice performance! As always, I'm happy to take tips and suggestions from you guys - please pitch in! -Teo

Thanks! Yeah I decided on the light bar because it was the best way to fit all the LED lights I had

Hello everyone! It's been a little while since I last posted; things have been busy with school, some health problems, and other things, but now I'm back with a fresh MOC, a RAM pickup truck, powered by BuWizz and 2 buggy motors! Here's a video of the model: I was fairly satisfied with the result. In low gear, this thing generates a ton of torque and still maintains decent speed, although the open differentials and low ground clearance make it struggle off-road at times. In high gear, the truck achieves decent speeds, but only on very flat surfaces. The biggest issue in high gear is that the whole drive train spins very fast, to compensate for the gearing down of the planetary hubs, and so a lot of energy is lost to friction. In summary, the features are: • 4x4 drive with 2 x buggy motors • Planetary wheel hubs • 2-speed gearbox • IFS and live axle rear suspension • PF LED headlights Here are some more photos of the model: The full photo album is on my BrickSafe here: https://bricksafe.com/pages/Teo_LEGO_Technic/ram-pick-up Overall, it was a fun little experiment. For my next MOC, I'm planning to build a rock crawler to compete in a local truck trial competition here in Toronto (If anyone is interested, please reach out, we will gladly take new contestants ). Hope you guys enjoy it! Any constructive criticism is much appreciated, as always, although I will say I'm done with this MOC and won't be making any changes, but I can use ideas on future builds.

Foarte tare! Do you have any videos of it driving? Also, I can't really see from the photos what parts you're using on the front for the driven independent suspension, is that the old CV joint? Did you have any issues with it popping out under the power of the buggy motors?

Awesome take on this Audi! One of my co-workers showed me this model this past summer, and I've been a big fan of it since, glad to see it built in Technic

Wow, that's an impressive improvement! I'm especially a fan of what you've done with the rear. The brick-built panelling covering the rear wheels improves the shape a lot, and by reducing the distance between the fender piece and the panel above it you've made the car look much more put together. Great work!

Awesome, appreciate it!

Yeah totally! I wonder if it isn't worth having a thread somewhere specifically for advertising LEGO-related events, it'd be nice to gather more people here in Canada. Anybody know how to go about that? @Milan Sorry to bother you, perhaps you have a suggestion?

Good point, that's definitely the case. I was thinking about the question of diffs vs. no diffs more generally, not for this specific axle.

I just love that Hoonicorn!! So much detail is packed in for a car at that scale. Si mie mi-ar place sa particip data viitoare la eveniment, dacă sunt in Romania, fiindca locuiesc in Canada dar vizitez aproape in fiecare an . Cel putin osa ma inscriu la forumul Rolug!

Thanks! The only mechanical change is I added a stopper on the middle axle so that the drive axle doesn't slip out under any circumstances. Other than that, the only change is to the look of the cabin Update October 3rd The video is completed, here it is!

Thanks a lot!! To answer your questions: The gear ratio coming out of the gearbox is: Low gear: 1:1.4 High gear: 1:3.89 The gear ratio from the gearbox output to the wheel, in the transmission, is 12.58:1, so the final ratios are: Low gear: 8.99:1 High gear: 3.23:1 As for the lack of diffs, I did not find this to be an issue. My steering axle had a sharp steering angle, which allowed the truck to have a good turning radius despite not having diffs to allow the wheels to turn at different speeds in corners. While the turning radius would have been improved slightly with open/lockable diffs, I think it was a good call because it saved weight by eliminating a diff locking mechanism. As well, the combination of planetary hub + defender rims made the pivot very close to the center of the wheel, which reduced the strength needed to steer. Thanks! The only mechanical change is I added a stopper on the middle axle so that the drive axle doesn't slip out under any circumstances. Other than that, the only change is to the look of the cabin

Update September 27 After a busy couple weeks, finally had time to redo the cabin and take some photos. Video to follow soon. More here: https://bricksafe.com/pages/Teo_LEGO_Technic/praga-6x6-trial-truck

Yeah, it was awesome! Hopefully the first of many. Update August 18 The final video is edited and finished, enjoy! Next step is to finish up the Praga truck and made a video with it as well.

Update August 16 This past weekend, Toronto had its inaugural Truck Trial! Thanks to @2GodBDGlory and @lmdesigner42 for participating, here is a photo of the 3 trucks that competed: All the trucks performed well, with different strengths and weaknesses. @2GodBDGlory's Lada was a monster of torque and power, speeding through the course but also destroying a few parts along the way, more info about it can be found here: @lmdesigner42's truck was slow but powerful and its winch really helped it out of some tough situations, but the added weight made some of the gears crunch under high torque as well. As for my truck, I was very satisfied with the performance. The drivetrain never had any breaking gears anywhere, and the only issue is once, under the worst conditions, the drivetrain slipped out of the middle axle, and this is something I will fix by adding some stoppers to limit the range of motion on that axle with respect to the chassis. The gearbox worked like a charm, as expected, as did the suspension. The steering, which I was worried wouldn't be quite strong enough, turned out to have plenty of strength, and the speed of it, and return-to-center provided by the servo was useful. I was also concerned that the lack of differentials could hurt the steering radius, but it turned out to have quite a good steering angle despite its long wheelbase due to its large steering angle, and the fast steering meant it wasn't time-consuming to steer back and forth several times for really tight corners. Overall it is definitely my most capable trial truck to date, and thanks a lot to everyone who helped with advice and feedback along the way, particularly @Zerobricks and @gyenesvi. As a next step, I'm going to redo the bodywork to look nicer, as it was just a temporary build for the truck to be ready for the race, and as I said before I'm going to fix the escaping drivetrain axle as well. As well, a video with the race will follow as soon as I have time to edit the footage. Below are the results of the race: Results Track 1 2GodBDGlory - 1:54 lmdesigner42 - 6:00 Teo - 0:42 Track 2 2GodBDGlory - not completed lmdesigner42 - 8:00 Teo - 0:20 Track 3 2GodBDGlory - 0:17 Teo - 0:19 lmdesigner42 - 5:00 Track 4 2GodBDGlory - 3:19 lmdesigner42 - 12:00 Teo - 2:00 Track 5 2GodBDGlory - 1:45 lmdesigner42 - 5:00 Teo - 1:43

In the end I did something similar to this, yes.

That would be ideal, sadly I don’t have any. I’ll get some perhaps for the next build.

I looked at your Mercedes 6x6 and I see what you mean, you linked the middle axle to the chassis, and the rear axle to the middle. I guess the only issue with this setup is that it does not implement the bogie design, but rather uses regular shocks on both axles, but it would appear to make the design more robust. In the end, this is the design I settled for, with a custom sliding axle design that is robust enough and allows more travel: With the competition only two days away I'm going to rush to make this thing drivable and add some bodywork, and I think I may continue to work on it afterwards to try to fix a few things. In terms of the robustness of the chassis, what techniques do you guys recommend to make it as strong as possible with the fewest parts, to keep weight down? One technique I always use is two have a 2-stud thick build made of beams and 5x7 frames linked together, but in this case, I would like to do things a bit differently as this does not fit above the portion of the chassis where the motors are, where the chassis is only 1 stud thick above and 1 stud thick below.

I know I'm late to the conversation, but I have to say this must be one of my favourite Technic trucks I've ever seen in terms of aesthetics at least. Phenomenal job!!

Yeah, that's a good point, I had thought of that as well but hoped it wouldn't happen lol. Frankly, I'm not too keen to redesign the rear axle suspension after all the effort that went into the current design, but if it must be done I guess I will. My question is how is it possible to keep a constant (or near-constant) distance between both the two axles, as well as from the gearbox to the inner axle?

Update August 2 Back from vacation, I'm resuming work on the truck, and planning to complete it by our scheduled race in 2 weeks' time. An issue I'm facing is on the rear bogie suspension system. While my setup is keeping a fairly constant distance between the two rear axles, and any variation is easily compensated for by the sliding CV joint piece, I'm finding that when the inner axle is lowered fully the sliding CV joint can fall out when the axle slides out too far. One option to fix this is to lower the universal joint coming out of the gearbox, but I don't like this solution as it reduces ground clearance. Another option is to add a set of two 16-tooth gears to raise the existing exit point from the inner axle by 2 studs, which again would allow the driving axle to stay more horizontal and fix the issue, but I'm not a fan of this solution either. Because the effect is so slight, my ideal solution would be to restrict the range of motion of the inner axle slightly to ensure the axle doesn't fall out. It only really falls out because of play at the bottom of the range of the suspension anyway, so this wouldn't reduce the suspension travel by much, rather just brace it better. Does anyone have any recommendations on how to build such a stopping mechanism without being too bulky? How do such suspension mechanisms restrict the range in reality? The following illustrates the issue:

Great, that fits perfectly. Time to order some