Search the Community

Showing results for tags 'differential'.

More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


  • Frontpage, Forum Information and General LEGO Discussion
    • New Member Section - PLEASE READ BEFORE STARTING!
    • Frontpage News
    • Forum Information and Help
    • General LEGO Discussion
  • Themes
    • LEGO Licensed
    • LEGO Star Wars
    • LEGO Historic Themes
    • LEGO Action and Adventure Themes
    • LEGO Pirates
    • LEGO Sci-Fi
    • LEGO Town
    • LEGO Train Tech
    • LEGO Technic, Mindstorms, Model Team and Scale Modeling
    • LEGO Action Figures
    • Special LEGO Themes
  • Special Interests
    • The Military Section
    • Minifig Customisation Workshop
    • Digital LEGO: Tools, Techniques, and Projects
    • Brick Flicks & Comics
    • LEGO Mafia and Role-Play Games
    • LEGO Media and Gaming
  • Eurobricks Community
    • Hello! My name is...
    • LEGO Events and User Groups
    • Buy, Sell, Trade and Finds
    • Community
    • Culture & Multimedia

Find results in...

Find results that contain...

Date Created

  • Start


Last Updated

  • Start


Filter by number of...


  • Start



What is favorite LEGO theme? (we need this info to prevent spam)

Which LEGO set did you recently purchase or build?



Website URL








Special Tags 1

Special Tags 2

Special Tags 3

Special Tags 4

Special Tags 5

Special Tags 6

Country flag

Found 36 results

  1. Inspired by the release of the planetary hubs and the diff lock idea from Zetors I decided to create a proper, realistic Tatra 8x8 with the following goals: Use of planetary hubs - Keeping it realistic, so no portal ones No load bearing axles - Most other models used the same drive axle to also hold the half-axles in place which increased friction in the driveline Realistic steering setup - Using a smillar mechanism the real trucks use Differential locks on all wheels - Each axle has it's own diff lock + a central one Here's what I came up with so far... The concept uses the blue bevel gears to transfer the power to the half-axles without spinning the pivot axle. This also allows for wheels to turn at different speeds when cornering. Once the power is transfered to the half-axles an additional gearing is used before the power is delivered to the wheel. Total gearing on half-axles alone is 1:9. Differential locks work by locking one of the differential's output to the main drive axle. As mentioned before all 4 axles have lockable differentials along with the central differential. Steering uses a couple of 9L links turned by the turntable acruated by an 8 tooth gear. This setup provides the front axles with slightly different steering angles. The model will probably powered with 4 of the BuWizz motors. Total gear ratio is 1:21 which should give the model around 900-1000 Ncm torque. I think the concept looks very promising so far and I will keep on building it virtually until I'm confident enough to order parts.
  2. This buggy contains a 3600KV brushless motor (2838). It has a pinion made from a LEGO axle and it runs a seriously good working drive-train. Together with the new 42109 differential and a (new?) 2D suspension method it turns out to be a fun car to drive. Please watch a video here. Especially the suspensions are worth having a look. More and more I'm using custom springs to create all sort of applications. Useful and useless. Almost useless is the spring-lock to open the hood. Very useful are the long front springs and the two-dimensional rear springs. Please let me know your comments. No building instructions available yet. If there is a need, let me know.
  3. Finally finished a first version of a LEGO RC Car with 2 in-wheel, brushless motors. While I know some of you hate the combination of RC electronics and LEGO, others enjoy these hybrid models (hence this post). If you are more the purist type and in favour of LEGO only, please skip this. If you like stretching the envelope using (RC) electronics please have look and let me hear your thoughts. While searching for brushless in-wheel motors I ran into the ideal product: Turnigy Multistar 4225-610Kv. It mounts easily onto LEGO (same measurements) and fits almost any 56-rim. The result is spectacular. Great speed, no wear-out, all traction goes to the wheels, no gears necessary. Sadly, it turns out this motor is no longer available (working on an alternative). Car also includes an (adjustable) software differential running on an Arduino Nano, works surprisingly well. When fully applied the car has serious oversteer, when turned to 0 the car has understeer. The body of the car is a 54100 modified boat hull . It took some cutting but ended up nicely. Please have a look at the video here:
  4. A compact sequential heavy-duty 4 speed remote controlled AWD gearbox Each gear of this remote controlled gearbox approximately doubles the speed of the previous. The output shaft contains an integrated lockable differential for AWD. See the video for a WORKING DEMO | FREE INSTRUCTIONS below. GEAR RATIOS 1st 6:1 2nd 3.3:1 3rd 1.8:1 4th 1:1 FEATURES compact remote controllable sequential gearbox 4 transmission speeds evenly distributed gear ratios differential output (AWD) differential lock single rotary catch many mounting points no half studs INSTRUCTIONS [PDF] [3D MODEL] REBRICKABLE: BRICKLINK:
  5. I rarely post but I check this site and other Lego Technic sites like Sariel's and GBC websites and I am stumped on a way to mechanically make this work. I am trying to use the Lego differential in a way that I have not seen others use it, at least in the searches I have performed. Limitations: Input motor needs to constantly run I would like to do this purely mechanically. Cannot use Mindstorms. Would prefer to not use switches unless necessary. Problem: I am trying to use a Lego differential to power two separate sections of my build. I don't have access to easy pictures so please see the simple diagram below. I have power on one axle and the two other axles will drive separate sections. I would like Section A to run constantly (or could potentially stop when Section B is running). Section B is currently being held up by a ratchet that completely stops the gear from turning until it is released, When released, Section B will run one full revolution then stop again until the ratchet is released again. The ratchet release is not on a pattern. It can be released 20 times in a minute then not released again for an hour. The issue that I am running into is that Section B currently has a higher load than Section A; therefore, when Section B's ratchet is released for the gear to run one full revolution, the load is heavier than Section A and Section B does not move. Solutions I can think of: Make the load on Section A larger than that on Section B so that when the ratchet releases, Section B will be easier to move than Section A and the differential will transfer power to Section B and it will work. I would rather not arbitrarily add to Section A's load unless that is the only way. Otherwise, maybe engage a ratchet on Section A to stop that section completely but then disengage exactly after Section B has completed one revolution and at the same time, stop Section B from running. I would think this is more difficult since at least one Section will need to run at a time so the motor and differential don't break but I could be wrong. I'm currently using the 28-tooth differential with 3 - 12-tooth bevel gears (BL: 62821b) inside a 5x7 technic frame Simple diagram: Section B ----------|---------- Section A -----| Differential |----- Input Motor Any help is appreciated. Thanks.
  6. There is one thing which has a great influence on off-roading performance, that is differential. Open diffs will severely cripple off-roading capability of a vehicle, but without a diff, turing radius is going to be awful. Can you really balance the two? I’m showing you two new MOCs regarding this topic: a Land Rover Defender & a monster truck. (There will be two new official LEGO sets which happens to be a Defender and a monster truck, I think this is pure coincidence...) 1. Land Rover Defender I have never tried building a model with no differentials. So maybe I should give it a try to see how it performs. The drivetrain is pretty straight forward: Then I started adding details to it. I was expecting it to be a lightweight model, but when it seems aesthetically acceptable to me, the final weight (1.3kg) is beyond my expectation (around 1kg). Other than that, the actual turing radius is really bad, something I can’t take. So Let’s not talk about performance, just take a look at some details: I have to say this MOC is not too sucessful, so I didn’t bother making a video for it. Even it is fully remote-controlled, to me it is still a display set. 2. Monster Truck So how can we really get maximum performance without losing the benefit of differential while cornering? Most of us know the answer: diff lock. We’ve seen so many great builds with manually or remotely controlled diff locks, and I want to make something different. Then I came up with an idea: Can I design an automatic diff lock, which locks when the vehicle goes in a straight line, and unlocks when it takes a turn? Of course in many cases the vehicle also needs that diff lock to be locked when it takes a turn, but considering it’s a fully automatic action without an extra motor to control the lock, This is an acceptable trade-off. Besides, other factors could somehow compensate for that, like grippy tires, responsive suspensions, etc. I soon realized that this is not going to be a tough job. I only need a simple mechanism that somehow links the diff lock to the steering motor (Servo motor). A video (4K) to show it all: The concept of this MOC came from Monster Jam trucks, that’s why it has roll cage and detachable body. The chassis and axles is no way near a real monster truck, it is built solely for the purpose of demonstrating the auto diff lock. And I think it performs great and seems reliable enough. Hope you like these two MOCs!
  7. I got my 42123 a month or so ago and while it's a very awesome set out of the boy I knew I had to give it a proper differential. Here's how I did it in LDD: In order to preserve the original engine position the differential is moved back one stud: A pair of 8 tooth gears transfer the power from wheels to the differential: And while I was at it, I also made the steering work using 8 and 24 tooth gears: I plan to make a detailed HOW:TO video tomorrow, so stay tuned. Meanwhile you can download the LDD here: Differential and Working Steering Wheel MOD.lxf
  8. I recently published my findings on using a sprung differential as a torque converter. I believe I have proved that a simple combination of a pb&g motor and a differential can amplify the pb&g's spring action down the drivetrain to compensate for a resistance on the wheel assembly. I would like to ask for some help with this. My mechanical engineering knowledge is topped out, and I'd really like to continue exploring this. Let me know if you have any ideas, more formal collaboration would be appreciated also. I'm looking at combining this torque converter with existing gearboxes, and also exploring its response at different speeds.
  9. Today is PI DAY! A very important day for all mathematicians to celebrate. What better way to celebrate than combining it with Lego Technic?! Here I present a PI Day special Lego Technic MOC that produces a gearing ratio of PI to 6 decimal places. This is using two differentials to produce a gearing ratio of 355 to 113. Happy PI Day.
  10. Here I present methods for designing N:P Lego Technic Gear ratios where N and P are prime using two differentials. Several differential topologies are presented and one cross connected topology is mathematically analysed and the relationship equation between the input and output derived. Using this equation and the computer solutions for the 1:N gear ratio designs, an example is worked through to create a 313 to 421 gear ratio. This gear ratio design is much more efficient than simply connecting an N:1 and 1:P design in series.
  11. Hi I have been learning about gear ratio designs for a while. I have been working on understanding the differential gear mechanism. It's fascinating once you start analysing and understanding how much you can do with this amazing device. In this video I briefly talk about why and when it was invented and then go over the mathematical relationship between the axles to allow easier designs of desired gear ratios. I illustrate a design of a 17:1 gear ratio and show a list of other potential design options for creating any of the prime numbers up to 53. Of course you can probably create any prime number but will explore that in a later video.
  12. In this video I present optimal computer generated solutions for designing 1:N (N=prime) ratios using a single Lego Technic differential. Insights and ideas are shown for implementing the 1:N designs in practice using Lego Technic liftarms with an example 421:1 gear ratio device. All the possible solutions for N less than 1000 are shown and can be used in your own Lego Technic MOC designs if you are needing to create a particular gear ratio.
  13. Hi. I was working on my car MOC (with a four-speed gearbox designed by Sariel) and had some unfortunate events happen. As stated in the title, the differential is somehow making the gear ratio higher than I need it. The gear moving the diff is moving at the same speed as the power input, but the wheel hub moves one rotation for every 3/4 rotation that I move the input shaft. Is this differential piece supposed to do this? I want the wheels to move at the same speed as the motor at 4th gear, which brings me to my next problem. I hear rapid-fire clicking noises every time my car is in 3rd and 4th gear. This happened to my other MOCs too, but I was able to solve it. Since the car is to be powered by two EV3 large motors, I actually believe there might be a clutch mechanism in the motors such as in the Technic linear actuators that also make a terrible clicking sound when they move all the way up or down. Whatever it is, I'm open to responses and hope the Eurobricks community could provide an explanation and solution about both of these issues. Here's some pictures, the orange and red pieces in the first pic were for testing the rotations. ' Thank you for your time.
  14. Hi All! Often a "reader", now a "poster", i´ve got a problem i cant fully wrap my head around. I try to keep a steering axle straight while going through a pivoting point or turntable. The axle should rotate with the pivot (eg in the picture below the yellow bricks should always align with the grey liftarms even if the liftarms are at 90 degrees of each other) but i want to rotate it manually on one side, with the rotation + offset of the pivot on the other side. Like the axle itself would have been twisted. The furthest ive got with this is pictured below and works as long there is no friction on the left output. I want both sides to rotate at the same time, but if you rotate the pivot/turntable then it should add just an offset "within" the axle. I dont know if this is actually possible or how to split the axle in two, add the pivot rotation to one part and then add both rotation together.
  15. (Sorry for mistakes (I'm not from Britain / America)) I was thinking about LSD (Limited Slip Differential) in lego. Because all I saw yet were just differentials with locking mechanism that engages after few turns of axle. And only thing it was limitting was main function of differential. So I came out with this solution - I know it isn't great, but it is very simple and compact (actually you add one rubber band inside differential (under spider gear)). What that does ? - When axles want to spin at different speeds (while cornering) more power is required (so you lose some speed if you don't have powferful motor) but, if one wheel lose traction the other one gets more power (compared to open differential) and you can also set how much additional friction you wat (by adding different number of rubber bands inside). Here is one picture of it : I just want to know what do you think about it, and if there is possibility to create a real LSD in lego.
  16. Hello, I've been building with lego technic for a couple of years, but found myself never having the right pieces for my builds. I recently bought a second-hand lego set with some nice wheels (8386). So I could finally start building some bigger and cooler cars. I started with my first supercar this week and am having trouble with the rear axle. I am using the method you see in this picture ( with 2 separate axles. The problem is that I want to use a differential, but can't figure out how that would work with this. Does anyone have a solution for this, or does anyone have a different, stable (compact) method for this? Any rear axle that has suspension is welcome. I would appreciate it to see more ideas from you. One more thing to keep in mind is that I only have the type of universal joints you see in the picture ( I don't have any other. Thanks in advance ;)
  17. I said before in my previous post that I had some problems with my GX EV3 4x4 chassis that I needed to fix. Once again, it's more gear grinding/clicking, but this time it's only in the front and rear differential gears. The grinding occurs whenever the chassis tries to drive into a wall or when it tries to drive in different conditions (because as an SUV it should drive smoothly in dirt or uneven terrain). What also annoys me is that when I push the car, instead of letting the motors move, the differentials make clicking noises that, like I said before, sound like a machine gun. I really need help so I can stop the differentials from clicking so when the car tries to drive into the walls, the motors won't still move while the differentials click, and so the car can be a lot more versatile on uneven terrain (such as what I used for testing, blankets) without the differentials causing a problem when the car moves. Here's some pictures of the bottom of the chassis.
  18. just made a truck similar with Mr. Madoca's new moc work same function on differencial lock and 2 speed gearbox,but 6x6 -Weight: g -2 XL motors for propulsion,1 XL for 1st axle,1XL for 2nd、3rd axle -2 Servo motor for steering,1st & 3rd axle -M motor for 2 speed gearbox -M motor for locking rear differential,1st axle - 2nd、3rd axle -Portal axles for 1st、3rd axle in order to make a powerful crawler, I need different rotating speed of front and rear axle. For the reliability, I not use the weak center differential. I design 2 seperate XL motors for 1st axle and 2nd+3rd axle. But I add a lock, to lock the 2 XL motors together when necessary. That means there are 2x 2speed gearbox + 1 lock. And to make sure the enough power, I add 2 battery boxs.
  19. Hi, I am seeing more and more locking differentials on MOCs, but I do not see how they are useful. Does anyone know why?
  20. Hello everyone, I have many old sets which are using this differential and as you can see, you can easily create differential lock using part But I was wondering - is there any official set which actually uses this parts combination?
  21. While playing around with the small turntable, I realised it can also be used to make a strong open differential, as follows (the red part of the differential need not be present, depending on usage): Top view : Side View : (lxf) I'll be using this as the center differential for my "Yet Another Supercar (Gen II)" . Another good place to use this is in mechanisms that uses those inner gears of a differential heavily - e.g. automatic transmissions that rely on a differential to detect overwhelming torque.
  22. After a little tinkering, I managed to create this self-locking differential. It locks when the car goes straight and unlocks when turning: A set of 12t gears are connected to the steering rack. When the rack is in the middle (and the car going straight), the two halfshafts are coupled together, locking the differential. When the rack moves to the left or right to steer the car, the 12t gears disengage with the 20t gears and let the differential act like an open diff: The main downsides I see with this setup are that the differential may stay locked during wide turns with small rack movement and the width of the axle is increased. A standard independent suspension with a differential and 68.8x36 ZR wheels (the combination I usually use) is 25 studs wide; with this feature it increases to 27.
  23. Four wheel drive on Lego Technic cars with small wheels is hard to realize, as they become relatively too wide (which is ugly) and the ground clearance is also compromised. The problem then is: how to get the same grip back with only rear wheel drive? Then you need to push something 'extra' in the back of your already crammed, small nice-looking vehicle... This concept is an approach to keep this 'something extra' as small as possible while giving awesome and unexpected grip to the car. (At least, I was astonished by what it achieved!) Instead of typing a lot, I've put it all into a video with the theory of how it all works at the back of the video to let the 7 billion minus 1000 viewers that are not interested into more advanced Technic stuff experience how it works in practice on a 2 cm (that is: inchy) thick ice floor. As for the car, it is built from Power Functions spares as all my L-motors (which have quickly become the main workhorse for every Technic builder) are ehm... in use. That is why you find me using a geared up XL motor, which gave me memories of the good old times when the poor knob wheel parts splattered around. Sharp images of the car and mechanism explanation can be found on: http://www.brickshel...ry.cgi?f=564319. On MocPages (beware, there is a piece of code there that simply destroys anything such as image resolution on .png files...) http://www.moc-pages.../moc.php/428881 Video: I finally have found PovRay so (with many thanks to all those who make that software) I can present a high-quality render:
  24. When I read the chapter describing custom differential in Sariel's book, trying to follow instructions to build it . Unfortunately, I only had "two" Knob wheels. Then I came up with a idea that is there possible to replace Knob wheels with double bevel g20t ? That means I have to build a different frame for three double bevel g20t which the 5X7 studless frame can not house. After trial and error of building process , I managed to build a frame that can enclose three double bevel g20t and connected it to a turntable . This differential is going to take more space than Sariel's when actually put to use. Here is a short video demonstration of this differential . A link to BS