Fosapifi

Thanks everyone for the feedback! By the way, the building instructions are finished an available for free at Rebrickable. https://rebrickable.com/mocs/MOC-131338/Fosapifi/tesla-semi-with-autopilot-and-torque-vectoring/#details The instructions for the trailer are following soon. It should be pretty easy to copy it from the video anyway.

The calculation in this video is not correct at all. First, he did not consider that the Tesla has much better aerodynamics than a conventional semi. Second, the drivetrain is much more efficient because it does not use gearbox, clutch and diff. Third, he assumed that the empty trucks have the same weight wich is not the case at all. Fourth, and I think this is his big mistake: He did the calculation for the range of a conventional semi. The Tesla has only one quarter of the range, which means that the battery needs to weigh only one quarter as well. In total, his guess for the weight should be about 20 tons to high. I think it is not fair to call it a "disaster" or "failure". One thing, he is right about is that EVs will not be a solution for traffic or climate change. Enough OT. I want to share some pictures of the unfinished model. I took them at Bricking Bavaria 2021.

The photos in the original post are pretty small, so here is a large one.

That was actually the big motivation to finish the model. I had a sleepless night for maling the video. I do not see the point in using PU. PF has stackable ports and more options, like pole reversers, extension wires, different battery boxes, RC system compability. The only thing I am missing is a programable app for SBrick+. We considered using EV3 wich would make the torque vectoring, autopilot, trailer steering and side flaps much easier but it was not possible with the limited space.

Nope, it was just trying different lever lengths. For testing, we layed the truck upside down and placed a sheet of cardboard on the rear wheels. The movement of the cardboard should match the front wheels angle. Another way to make the effect visible is connecting both sides with a diff, one side reversed. Considering the density of electric elements and cables, it probably could... 2 persons working on one MOC means twice as many ideas and twice the amount of endurance. I know this is not very common, but we, Pirmin and Levin, work always together. I, Levin, do all of the postings on EB, YT, etc. As the driving motors are controlled by pole reversers, directly connected to the battery boxes, there is only full speed. In the post I mentioned that analogue speed would be possible with another servo and diffs. As far as I know, a mechanism like this always needs some kind of restoring force. In one state the potentiometers both have to be turned all the way up. The servo must turn one of them down, while not being able to turn the other one any further. You could use a spring, rubber band or counterweight. In a earlier prototype, we had a similar mechanism for the side flaps, to match them to the angle of the trailer while steering. We decided to use counterweights for 4 reasons. 1: It is different from standard solutions. 2:Counterweights should have less wear than springs or rubber bands. 3: It looks cool and exotic. 4: We wanted to show off with our EV3 steel balls. It is obvious that we had to implement the counter weight again when we ditched the idea with the flaps.

One more overengineered MOC from us: We started this project in summer 2018. It was nearly finished in late 2019. There was only one problem left... Like the prototype of the real truck, our model has 4 motors for driving, one for each rear wheel, without differentials. While steering, the motors would stop because they could not handle the speed difference of the inner and outer wheels. We thought of three solutions for this problem. 1: Use a high enough torque to grip ratio to make the wheels slip - not possible for this truck, 2: Use 24t clutch gears on one side - worked only while steering to one side and 3: Program the motors to slow down, matching the steering radius - not possible with the SBrick app. We paused the project until we came up with a torque vectoring system this year, 2022 (still less delay than the real truck's production). You can see how it works in this video (at 0:45 - 2:35): Functions of the finished model: - driving (4x PF L-motor, 1x servo motor) - steering (1x PF servo motor) - torque vectoring (1x PF servo motor) - fifth wheel lock (1x PF M-motor) - moveable side flaps (1x PF M-motor) - openable doors and front trunk - Autopilot (2x WeDo 1.0 motion sensor) Functions of the trailer: - raiseable supports (1x PF M-motor) - lifting the first axle (1x PF M-motor) - passive trailer steering, connected to the fifth wheel Is the torque vectoring system the perfect solution? Probably not. The driving works a lot better than without the system, but steering with the extra weight of the trailer still slows the truck down. The best option would be differentials. Our setup only allows to use the driving motors at full power. In theory you could control the driving motors proportional to the steering angle and the desired driving speed at the same time, by connecting two servos to the battery boxes. One to slow the inner wheel down while steering, the other one to have proportional speed control, connected together with a diff for each side. If you want to be able to drive backwards as well, this would be an insanely complicated mechanism which does not fit in such limited space. Disappointingly, the SBrick app still does not allow to use sensors in the control profile editor. For the Autopilot mode, we had to use the open source BLE protocol of the SBrick+ to write a simple code. By default, the truck is driving forward. If one "motion sensor" detects an object, the truck steers to the other side. If both sensors detect an object, the truck stops. The WeDo motion sensors can neither detect motion, nor distances. They only detect if their IR light is reflected. The distance depends on the colour and the brightness of the object. We had the best results with reflective materials. Light, shiny materials also work. If the object is to dark, the Semi will hit it, before stopping or steering. Some more pictures: By the way, the production version of the Semi has a longer cabin, longer wheelbase, side mirrors, no covers for the rear wheels and only 3 motors. This model resembles the prototype, presented in 2017. As always, we plan to make free building instructions.

Wow! The design is very well composed, using a high density of panels. The drivetrain does not use differentials, right? Does that affect the performance while cornering? When I tried this, the battery box would always shut down becaues of the extra load.

I want to show you some more details of the bus. The bellows are more complex than they look from the outside. The maccaroni pieces at the top need to rotate freely, while the axles have to hold the liftarms and the maccaroni pieces at the bottom. This would be very easy, if 22l axles existed. we came up with a combination of end stop axles, frictionless pins and thin liftarms with axle holes. The 1x5 liftarms simulate the extra bellows that the real bus has in the lower part of the interior. We came up with a super compact i6 fake engine, 3x2x9 studs, which did not make it into the final model. The pistons are crank parts and the crankshaft (actually camshaft) is made out of headlight bricks. It was ment to be powered micro motor, directly from the battery box. Two of our favorite details are the camouflage u-joint and camouflage s-brick:

Could someone delete both attachments from the first post in this thread?

Yes, they are. The weels are always the first part when we build a new model. The bus ended up being 21 studs wide, because we wanted the corridor between the weels to be 5 studs wide. 19 studs would probably be more accurate.

Done. Here are the pictures: https://bricksafe.com/pages/fosapifi/man-lions-city-articulated-low-floor-bus

I just uploaded one picture. Is there any possibility to upload pictures bigger than 0.1MB? While kneeling down, the air has to pass a half engaged switch. While kneeling up, the air can get straight into to the cylinders. In the beginning of the building instructions there is a pneumatic plan, which might help you.

It has been quite a while since I last posted here. But this Project seems to be worth sharing with you. At 9869 parts and 8.4 kg, it is by far our largest project. The goal was to include motorized driving and pneumatic suspension without using any of the interior space. So yes, it has a real low floor going through the whole length. RC-functions: - The third axle is driven using 4 PF L motors, 2 CaDA metal u-joints and the new LEGO heavy duty diff. We destroyed many parts while prototyping. We tried to include a 2-speed gearbox, off-center diff, no diff at all and single wheel drive. The current setup is the only one which was working in the end. - The first axle is steered by a PF servo, located under the driver seat. - The bus has two separate pneumatic systems. One for the suspension and one for the doors. Both have their own manometer and pump, actuated by a PF L motor. The suspension system has 2 air tanks, the door system has 1. - The left suspension can be raised manually with a switch in the driver's cabin. The right side is operated by a PF servo. We included a check valve to enable slow kneeling. The switches are connected in such a way that the pressure in the air tanks is always kept while kneeling. The suspension system uses 22 small pneumatic cylinders and 10 shock absorbers. - The doors are also operated by a PF servo. The second and third door can be disabled separately from the driver's cabin. The system has a total of 6 cylinders. - We managed to hide a micro motor under a seat behind the first axle. It is used to unfold the wheelchair ramp. We used a red 9244a u-joint to hide the mechanism in the side wall. - A total of 8 LED pairs is used for the lighting. The functions are controlled by 4 s-bricks. For power supply we use one 84599 rechargeable battery box and one buwizz brick. The bus uses 14 extension wires and 14+ meters of hose. One of the hardest challenges was to prevent the bus from bending. The floor is only 2 studs thick and has weak spots over each axle. The roof is responsible for the rigidity while only being connected to the lower section with a few liftarms. It also houses most of the technic. There are several tight spots where every millimeter is used for hoses and wires. Problems: The suspension system is very unreliable. Many of the small cylinders leak if they are unevenly loaded. We had to buy more of them than we need and still the kneeling does not work every time. The front and rear section are only connected with one turntable in the roof and one pin in the floor which makes it hard to pick the bus up. The building time was 3 years with many breaks. We wanted to replicate the exact version of the bus which is used in Munich. Unfortunately all articulated buses with 3 doors were retired during the building process. It is very disappointing that we could not build it in blue because LEGO thinks it is a good idea to use 5 different shades of blue than releasing all basic parts in one color. As usual we published free building instructions at rebrickable: https://rebrickable.com/mocs/MOC-126294/Fosapifi/man-lions-city-g-articulated-low-floor-bus/#parts If you want to watch the instructions for entertainment, we also have a video version: https://www.youtube.com/watch?v=GiKy4xixxmo You can find a very ugly pneumatic plan in the instructions. The bellows are a further developed version of Sariel's design: https://www.youtube.com/watch?v=I8_YJK_WNpY Also big shout out to the incredible CapaCity L by krolli: https://www.eurobricks.com/forum/index.php?/forums/topic/167663-articulated-bus-like-capacityl/

Do we already know the main color(s) of 42099? Was the set shown in Nuremberg dbg like the leaked pictures?

We had slipping gears only when driving against a wall. Surprisingly we had no problems with the u-joints. The axels are also in good condition because we lubricated the whole transmission.

Sorry, I have no idea how to upload pictures bigger than 0.1MB. I just posted some LDD renders of the drivetrain on Instagram. You will get a deeper look inside of the model when the building instructions are finished. https://www.instagram.com/fosapifi_lego_technic_mocs/

The fast mode makes the Tesla pretty much double the speed compared to the slow mode. Buwizz also allows propotional speed which means the model drives in any speed you want from 0 to the maximal speed. https://www.instagram.com/fosapifi_lego_technic_mocs/

Hey guys! After working on this model for more than 6 months, we finally want to show you our new Tesla Model S: Manual functions: - openable doors, trunk and frunk (front trunk) - foldable rear jumpseats RC functions controlled by 2x Buwizz brick: - RWD (8x PF l motor) - steering (1x PF servo motor) The biggest challenge was to bring the whole power to the wheels. The differential is powered from both sides and we use old style 9244a u-joints. What is your opinion about this high count of motors? Do more motors really make the model faster or do they only increase the weight and part wear?

Thanks! It´s not a scaled model of a real snow groomer.

Hey guys! Our latest project is finished. We hope you like it Remote controlled functions: - drive, steering - 4 XL motors - turn the crane - 1 M motor - winch - 1 M motor - 6 pneumatic functions - 4 servo motors Motorized functions: - raise the tracks - 1 L motor - pneumatic compressor - 2 L motors - PF lights

Wow! You added so many functions to this set. Very clever to use a linear accurator for the pneumatic switches!

I know it´s hard to combine technic and system, but this one looks really impressive!

Good job! I think you are very talented in designing complicated shapes!

It looks very impressive because of all these hoses!

Good job! I especially like the space for tools under the ladder. It´s very cool if big models have small details like this! Is the wing-body mechanism based on madocas truck or is it completely new?