Search the Community
Showing results for tags 'Gearbox'.
Found 156 results
-
Hi All, im currently in the throes of building a transverse fwd Lego moc. It’s in its early stages at the mo, it it has an ultra 4 speed gearbox, engine and differential all mounted transversely. Ive still to do a bit of work on the gear selector to make it a little easier, but here’s a small video of it in its current state if if you see bits of your Lego Design in this model, thanks for the inspiration
-
Hi guys! At least I has finished my next MOC and want to introduced the finished model to all of you! Welcome my International Lonestar truck! It's dimensions are: - Lengh: 101 stud or 80 cm - Width: 31 studs or 25 cm without mirrors - High: 37 studs or 30 cm excluding antennas and exhaust pipes. It consists of more than 5000 Lego parts, including 9 motors. It has: - Great Charbel's 8 speed gearbox, modified by me to the 16 speed one by adding high/low gear to the main output. It has a special shifter. It's all RC. - Independant powerfull pneumatic brakes on each wheel. Inspired by Sheepo's Peterbilt. - Pneumatically controlled fifth wheel. - Independant suspencion on front and dependant one on the rear axles. - Suspended driver's and passenger's seats, doors with locks and shock absorbers. - Detalized interior. - Inline 6 cylinder engine like the real truck. Power functions is described at the picture below, I think this is more interesting than just to read. Also I include pneumatics sheme. Enjoy the pictures please, I hope some video will apear nowadays. Unfortunately, rear differentials can't cope with such a huge torgue and truck cant drive fast on the floor, sorry. Please visit my Bricksafe page for more photo. Building instructions are available here: https://rebrickable.com/mocs/MOC-9788/OleJka/international-lonestar-truck/#comments VIDEO AVAILABLE NOW!! -
[MOC] Remote controlled 4-speed AWD gearbox
harriedegroot posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
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] https://bricksafe.com/files/hdegroot/remote-controlled-4-speed-awd-gearbox---with-perfect-gear-ratios/remote-controlled-4speed-awd-gearbox-with-differential-lock.pdf [3D MODEL] https://bricksafe.com/files/hdegroot/remote-controlled-4-speed-awd-gearbox---with-perfect-gear-ratios/remote-controlled-4speed-awd-gearbox-with-differential-lock.io REBRICKABLE: https://rebrickable.com/mocs/MOC-83457/hdegroot/remote-controlled-4-speed-awd-gearbox-with-perfect-gear-ratios BRICKLINK: https://www.bricklink.com/v3/studio/design.page?idModel=244834 -
Toyota Supra MK4 A80
Matiss56 posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Toyota Supra MK4 A80 So I have been working on this car for quite a while now and want to show off the work and here some opinions. The car features: 6 speed gearboks with realistic gearshift Detailed engine Openable Doors (with realistic doorhadels) openable hood and trunk Hope you like it :) More details and video, can be found on rebrickable :) https://rebrickable.com/mocs/MOC-62982/TheMatiss56/toyota-supra-mk4-a80/#details -
Hello everyone, Let me introduce ma latest creation, a Jannarelly Design 1 at 1:9 scale. Jannarelly is a French car manufacturer based on Dubaï : https://www.jannarellyfrance.com/histoire. We feel a lot of Cobra Shelby or Ferrari 250 Testa Rossa design inspiration. It is a Neo-retro style : New materials on old shape ! SPECIFICATIONS : - Dimensions in cm (L x l x h) : 44 x 20 x 12 - Dimensions in studs (L x l x h) : 54 x 25 x 18 - Ground clearance: 1,3 studs - Weight : 1,3kg - 2 000 parts FEATURES : - 5+R gearbox - HOG (at the back) + working steering wheel - Openable cockpit canopy - Transverse V6 engine - Independant suspensions - Front axle: Ackerman steering, caster angle, steering radius : 55cm - Openable doors, front trunk and engine cover - And a cool stripe ! On picture below we can see elementary features : The HOG is connected to a gear reduction 8t/24t to enhance wheels rotation. Front axle has a positive caster angle. I re-use @T Lego one from La Ferrari : https://bricksafe.com/pages/T_Antonie/ferrari-laferrari The cockpit canopy can rotate to see interior details and give a better access to gearbox lever : The gearbox is a 5+R architecture like Shelby @Sheepo : https://www.sheepo.es/2013/10/ford-mustang-shelby-gt500-14.html. The main column is taken from @Charbel Volcano RS design. Ratios are : R - 1:134 1 - 2.1:1 2 - 1.67:1 3 - 1:1 4 - 1:1.33 5 - 1:1.667 Back 3D view below : Each driving ring (middle, left and right) has its own linkage (pink, green, blue). There is no "no back" system like @Gray Gear https://www.eurobricks.com/forum/index.php?/forums/topic/177499-how-to-6speed-manual-transmission-with-safeshift-system/ or NK03 gearbox design because too big to fit in. INSPIRATIONS : Nico71 : http://www.techlug.fr/Forum/viewtopic.php?f=5&t=9776 Jeroen Ottens : https://rebrickable.com/mocs/MOC-2927/Jeroen Ottens/alfa-romeo-4c-spider/#comments T-Lego : Charbel : https://rebrickable.com/mocs/MOC-9613/Charbel/volcano-rs-supercar/#comments CONCLUSION : It was a real pleasure to work on this car : design working and features implement were a good challenge ! HD photos on this link : https://flic.kr/s/aHsmR3ZYCx Thanks for reading, I hope you will appreciate this creation ! See you ! -
.thumb.png.116032e930e483fb4ebbfdc62183bd34.png)
[MOC] Rugged supercar - Hammerhead (1:9 scale) - Revisiting
Didumos69 posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Rugged supercar - Hammerhead (1:9 scale) This project was not something I started very consciously. Also for me it evolved into something special. I was especially happy with the interference (in a positive way) of other builders. A big thank you to this community, for pushing me in the right direction on several occasions! The most special part - to me - of this build, is the chassis. It combines a simple 4-speed AWD transmission, a flawless sequential shifting mechanism and advanced suspension setups with Ackermann steering, anti-roll bars, torsion bars, 2 studs ground clearance and 2 studs suspension travel. All wrapped together in a very flat yet rigid and coherent structure with a mid-console width of only 5 studs. I did not want the bodywork to make any compromises to these features. I wanted the body to continue the line of durability set in by the chassis. Flex-axles do not fit that image, hence no wheel arcs. They would also sit 2 studs above the hood - not very elegant. The result is a car that does not only look fool-proof; it is fool-proof. After a rough treatment, you don't need to tighten connections or fine-tune gears to avoid friction. You can carry the car by the sides, by the trunk door (rear wing), by the nose and by the bumpers without displacing any parts. You can even grab the 2Kg build by the roof and turn it upside down to see the bottom side without a problem. So I did not intend to level with great bodywork builders. To me the biggest compliment is that some have referred to this model as the successor of 8865 and 8880. Drive train AWD with 3 differentials Sequential 4-speed gearbox One-finger shifter V8 fake engine Suspension Double wishbone suspension Anti-roll bars (front & rear) 2 studs suspension travel 2 studs ground clearance Steering Ackermann steering Gear-rack sliders Working steering wheel HoG steering Chassis Sturdy and durable Integrated bumpers Adjustable seats Narrow mid-console (5L) Bodywork Sturdy and durable Integrated roll-cage Lockable doors Openable trunk Liftable By the roof By the sides By the nose By the trunk door Instructions are available on Rebrickable. There is a full-featured version called 'Rugged supercar' and a chassis-only version called 'Flat AWD chassis'. The chassis-only version confines itself to part 1 of the instructions of the full-featured version. Special thanks to @Blakbird and @BusterHaus - with Blakbird being the driving force - for taking on the task of making these beautiful instructions! Making instructions for a build like this is a tremendous amount of work. Even more so, given the fact that I have been very demanding in sticking to my original design. - 32005a (Link 1 x 6 without Stoppers) - used for the anti-roll bars and steering tie rods - is preferred over 32005b (Link 1 x 6 with Stoppers), because each link has tow-balls inserted from both sides. 32005b can be used too, but in that case each link will have one tow-ball that needs quite some force to insert. - 32056 (Liftarm 3 x 3 L-Shape Thin) - used for the door locks - is preferred over 32249 (Liftarm 3 x 3 L-Shape with Quarter Ellipse Thin). 32249 can be used too, but makes it more likely to accidentally lock the door while it's open, which is not a big deal of course. - 76138 (Shock Absorber 6.5L with Soft Spring) - used for the door locks - should be soft springs. They are quite rare in red, but you could also use two LBG soft springs. - 85543 (Rubber Belt Small (Round Cross Section) - used for the 90 degree limiter and the return-to-center of the gear shifter - should be relatively new, say max 2 years. Not that they wear out quickly, but the older ones are slightly less tight. Images of the full-featured version can be found here. Images of the chassis-only version can be found here. See the entry on The LEGO Car Blog! P.S. Where real cars start with a sketch, evolve into a professional design and finally have their technical details filled-in, this project started with some technical details, evolved into a complete design and ended up in a sketch ;-). By @HorcikDesigns (http://horcikdesigns.deviantart.com/gallery/). -
Multi Function Gearbox using a single motor MOC
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hi there, this multi function gearbox implements two separate functions using just a single motor. It implements the two functions by exploiting the direction of rotation of the motor and implementing one function for the forward direction and a function selector in the reverse direction. The reverse selector can be used to select between between driving one of the two outputs in either the forward or reverse direction. This means you can build a remote controlled car or device that has two functions that can be remotely controlled with just 1 motor and just 1 channel of your remote transmitter and receiver combination. -
Ultra Compact 8+N+R Sequential Gearbox
Anto posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
This gearbox is an upgrade of my ultra compact 8-speed sequential gearbox. The 8-speed gearbox was nice but it was frustrating to know that the 2-speed gearbox took as much space as the 4-speed gearbox. I thought about transforming the 2-speed gearbox into a 2+N+R one. I had an idea about how to transform this gearbox but I didn't really think about how to activate the reverse and the neutral. Maybe by doing something with the knobs... I spoke with @Charbel and he gave me the idea to use the Bionicle parts I already used on my previous gearbox. Then I ended up with this: I used large frames as in the Lamborghini Sian. They make the whole gearbox stiff and now you have just to build a chassis arount the 'box! The neutral was extremely simple to do. See by yourselves: The reverse was more complex to create. For every foreward speed, the 2+N+R-speed gearbox rotates the 4-speed gearbox by the red 16t at the bottom. The reverse doesn't use the 4-speed gearbox, it uses the blue 20t at the top of the picture below: To engage the neutral and the reverse, I fixed two Bionible parts on the left knob. So they act as a smaller knob, with two teeth, and at a point 1/4 turn of the right knob makes the left knob rotate by 1/4 turn, whereas for all the foreward speeds, the left knob does 1/4 turn every turn of the right knob. Reverse engaged: Neutral: First: There is a stop not to shift from the 8th to the reverse. The engine and the gearbox wouldn't appreciate. The wheels have to be connected the the red axle and the engine to the grey one. It's possible to use this gearbox for a 4WD vehicle easily since the red axle goes through the gearbox. With this gearbox you don't have to use a 8-speed gearbox and a DNR one anymore, as in the Chiron or the Sian. It saves space, and you can't engage the 4th speed whereas you are in neutral - all the speeds shift into a logic order. I will make instructions when I have time! -
Dual Function Gearbox
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hi Everyone, I have just created a video about my dual function gearbox allowing you to remotely drive and change gears using just one motor - i.e. the one motor implements two functions. The gearbox implements two functions at once by exploiting the direction of rotation of the driving motor and implementing one function (driving) for the forward direction and gear changing in the reverse direction. -
transparent.thumb.png.64c75cc99e499bf757c13576b785e380.png)
[MOC] Compact gearbox with reverse
BrickDesignerNL posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
I'm working on a small model that needs to revers it's pattern when it hits the end, and again when it's at the start (like auto-reverse in an old cassette deck). This is the first concept draft I made using only pieces from 51515-1 and no clutch gears and driving ring, and utilizing the "double bevel" feature of the gears. Resulting in a 2.5L instead of 5L gear width. How it functions The long axle turns, the 12 gear double bevel on the yellow axle can be pressed in two sides, press left and it turns in the same speed and direction, press right and it will turn in the opposite direction of the black axle. Part list and building instruction can be found here: https://rebrickable.com/mocs/MOC-65251/BrickDesignerNL/easy-push-to-reverse-gear/ TODO I would like the reverse to turn in the same speed as the forward. - so size will change -
8110 - Unimog - MODs and Improvements
tripletschiee posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
I think, it would make sense to open a new thread for the Unimog 8110 U-400, that includes all the MOCs, changes, improvements on the Unimog. It should also contain all the new attachments, equipments, that people build. It should show their ideas and what they are creating for this cool set. I am looking forward to see your creations! I'll start today. I implemented a pneumatic driven cargo bed. It is driven by the original motorized pump and works pretty well. The lifting angle could be better. So there is still room for inmprovments. For more pictures of this MOC plesae vistit my Flickr-page or (after publishing) my Brickshelf-folder. Regards, Gerhard -
7+R sequential gearbox (DCT)
Leviathan posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hi everyone, Lately, I read topic on Audi R8 from Jeroen Ottens (https://www.eurobricks.com/forum/index.php?/forums/topic/178368-wip-audi-r8/) and it remembers me that I had such a prototype of a sequential gearbox. It's an improved version of my sequential gearbox used on my Bugatti Chiron 1/8, lighter and more compact. I use 4 orange rotary changeover selectors. I just want to say that is only a prototype version unfinished that I wanted to share with you. Please do not judge assembly design, but system core. How does it works ? - The main shat is the center one and it's made the dual clutch shaft - On each side, there is 1 half-gearbox. One with odds speeds (1, 3, 5, 7) and the other one with even speeds (R, 2, 4, 6). - On main main shaft, there is an offset of 90° between the 2 orange changeover. Its engage only at time one of the half gearbox. The real secret of the gearbox is the offset between each half gearbox. I used a factory wheel with 2 pins with tow ball to create this offset. See the picture below : Of course, the gearbox has a end stop to prevents 7 to Reverse shifting. Ratios ; R : 1,2 1 : 0,6 2 : 0,75 3 : 1 4 : 1,67 5 : 1,8 6 : 2,1 7 : 3 The reverse speed is too fast. I worked to an improved version too, smaller that prototype. The arrow shows the right way to shift up. Finally the video to understand the mecanism : I hope you will like it ! See you soon ! -
Lego Technic RC 3 Speed Manual Gearbox
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Here I've created my first attempt at a RC 3 speed gearbox allows you to change gears up and down using a power functions remote control. The gear changing mechanism is implemented using two parallel axles each with gears arranged in such a way that shifting one of the axles to one of three possible positions meshes the gears with 3 different gearing ratios. The gearing ratios implemented are 3:5, 1:1 and 5:3. The gear shifting axle is controlled by a lever mechanism driven by the 4 state stepper from the bugatti chiron set. This mechanism in turn is driven by a medium power functions motor activated by the remote control. Hope you like it. -
[MOC] Rolls Royce Phantom (2018)
Appie posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
I am still looking to tweak a few spots (the panel at the rear window is included in this), but mostly it is finished: 20190827_134133 by Appie NL, on Flickr 20190827_134604 by Appie NL, on Flickr 20190827_135244 by Appie NL, on Flickr 20190827_134945 by Appie NL, on Flickr I don't think I mentioned this before, but the "gas" and "break" pedal function as the forward/neutral/reverse for the gearbox. If I did the math right, then the reverse gear ratio is slightly above the ratio of the 2nd, perhaps not very realistic since afaik they are usually around the ratio of the 1st, I couldn't figure out a better ratio in the space I had left for this. 20190827_134741 by Appie NL, on Flickr 20190827_135042 by Appie NL, on Flickr The white levers with silver knobs control the windows and the black one on the dash controls the airconditioning. The lever below the steering wheel is for the lights. My aim was to have the positions for these controls as close to what they would be in a real car. Despite the roof being open, the front window levers are a little hard to reach for my big hands (especially with my left as you will see in the video below). 20190827_153707 by Appie NL, on Flickr 20190827_135520 by Appie NL, on Flickr My attempt to recreate the "star filled heaven" roof lining of the real Phantom. These are "glitter bricks". They only come in weird colours like dark pink until a set of Harry Potter brought these light blues. I considered adding PF lights to this for extra effect, but it didn't have the desired result in terms of lightning and I didn't want to use 3rd party stuff on this build. 20190827_134306 by Appie NL, on Flickr 20190827_134407 by Appie NL, on Flickr 20190827_135313 by Appie NL, on Flickr Behind the back of the trunk is the gearshifter from Attika and some wires. 20190827_140703 by Appie NL, on Flickr Perhaps looks a little bright in this picture, but there's only 2 PF leds per headlight on these. 20190827_140547 by Appie NL, on Flickr And the taillights, 1 PF led each. 20190827_140944 by Appie NL, on Flickr @Attika Here's your desired belly shot I don't have the new wire holders yet from Control+ sets and not sure of these can even hold 2-3 wires in 1, so I made something myself to hold/tunnel/guide the wires. At first I wanted to completely cover up the floor and "hide" the Technic like I mostly did on the rest of the car, but decided to keep it open. And some might notice that I updated the front suspension. When I nearly finished the build it needed an upgrade to 3 hard springs, same number as the rear, since the front suspension was pretty much dead in the old configuration. And a little video to showcase the windows and airconditioning Original opening post below this point: With all the great sportcars on this forum, I felt I had to try a different approach to the "1:8 Lego supercar". Choosing this car also gave me a good excuse to add different kind of functions usually not in these kind of cars. First of all I want to say thanks to a few people on this forum for information, techniques or mechanisms they provided: @Didumos69 and @jb70 for their work on the Chiron gearbox. This model uses their efficiently build Chiron gearbox, I only tweaked it slightly further to make it shorter. Also thanks Didumos and @Erik Leppen for their information on suspension, made it easier to look for how to fix stuff. @Attika for his compact servo based gearbox stepper which I used in this model. @Jeroen Ottens for all sorts of neat techniques and tricks in his DB11. The front mounting of the suspension is very similar to his to get the engine very low like in his DB11. I am sure I forgot a few people, my apologies. So here's the current progress: WIP3Frontside by Appie NL, on Flickr WIP3RearSide by Appie NL, on Flickr WIP3Side by Appie NL, on Flickr The current features are: - 8 speed gearbox - V12 fake engine - Suspension - Electric windows - "Airco" - Lights I think, despite the outer shell being about 70% system bricks and 30% technic, the base of the car is all Technic and that it should belong in this forum and not the scale forum. This is how the car looked in the early stages: WIPRollsPhantomFront2 by Appie NL, on Flickr But if Jim or Milan thinks it should still be in the other forum, I am sure he will move it. The reason for the mostly system outer shell is because I had a hard time making all the little curves with Technic (panels) and I felt those little curves made the difference to try and capture this car. Especially at the front, after that I tried to minimize Technic panel use because it would be a breach of style at that point. Overall I am happy how it turned out so far, some parts I don't like. The windscreen being the biggest offender with how square and flat it looks, but the A-pillars being part of the structural integrity of the model made it hard to come up with something else. Stuff left to do: - Dashboard and midconsole - Front seats - Roof - Mirrors - The bottom 2 studs of the model (under the doors, bottom of front grill and the second layer of the floor to hide wires and provide more rigidity to the model) -
[MOC] 90 degree stepper for servo motor
Leo12 posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
This is a new stepper designed for use with the power functions servo motor. The output will spin 90 degrees every time the servo fully turns to the right or left and returns to center. The basic concept is that when the servo leaves it’s center position one of the ratchets on the differential housing disengages. As it continues to rotate the other ratchet stops the housing from moving, rotating the output. When it returns to center the engaged ratchet allows the housing to slip, so the output remains stationary. If you plan on building this yourself and it is not turning reliably check that the ratchets can rotate easily and the rubber band has enough tension. -
Tiger 4 x 4 x 4
Zerobricks posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
After completion and playing with the Leopard for a few months, I noticed the model had a few shortcomings which I wanted to eliminate with this version. These include: Suspension oscilations at high torque High center of gravity Instability on rough terrain at high speeds Most of these issues were due to the usage of the torque tube suspension which is simply too heavy and unresponsive at high speeds. What I needed was to replace the live axle suspension with independent suspension while keeping the articulation needed for offroading. Here's what I came up with: Let's break down the suspension to it's basic components to better understand how it works: Colored green are the main shock absorbers. These caryy most of the wight and provide a high suspension travel Colored orange are the gearbox transfer arms which fix each perpendicular gearbox firmly to the suspension, thereby reducing friction and fixing the U joints to keep them from popping out. Colored black are the side beams which help guide the transfer arms and hold the suspension together Colored in red and gray are the two independent drivelines powering the wheels. Finally in transparent, the suspension arms are made as long as possible for maximum suspension travel. I built the first version with this setup, but soon discovred a flaw. The torque from the drivelines would push the suspension arms down, causing the suspension to stop responding (indicated with red and grey arrows in photo above). In order to solve this problem I added the suspension bridge above, colored in pruple. The suspension bridge performs the following functions: Compensation of the driveline torque Supports 20% of the model's weight Improves articulation when going over rough terrain With the suspension solved, I turned my attention to the chassis. I wanted a model with high torque and high speed. To achieve that I installed a two speed gearbox for each independent driveline powered by a total of 4 RC motors: Finally a very sturdy chassis based on frames was built to support the model. Each axle was given it's own independent steering with servo motor and each driveline has an M motor for switching gears. This redundacy means that even if half of the model breaks down, it can still drive back home. Next step was building the model in real life. Thanks to ForwART's custom stickers the exterrior really came to life: The doors can be opened, revelaing two seats and the steering wheel: Each wheel has over 6 cm of wheel travel, allowing the Tiger extreme articulation rivaling live axle setups: And let's not forget the most important photo of them all: Finally, since there is only so much I can tell in words, enjoy the video experience: As usual the LDD file of the model is available by clicking the photo or link below: https://www.bricksafe.com/files/Zblj/tiger-4x4x4/Tiger 4x4x4.lxf To summarize, compared to the previous Leopard, the Tiger has the following improvements: Improved stability due to the independent suspension and low chassis Higher top speed due to the gearboxes Eliminated suspension oscilation Improved performance at high speed thanks to lighter and more responsive independent suspension Improved maneuverability thanks to all wheel steering Sadly there are also a few drawbacks which I plan to fix in the future version: When pushing the model hard in Ludicrous mode and in low gear the 12 tooth bewel gears can get damaged and need to be replaced Low steering angle (18 degrees) Because only one servo motor is used per axle, steering is more prone to be bumped out of center. -
Improved theory automatic gearbox
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hi All, This video demonstrates an improved design of a 2 speed automatic gearbox based on a theoretical approach. Typically a Lego automatic gearbox consists of two stages namely a gear selector and a torque detector. In this video, both of these components are improved upon. The gear selector gear count has been reduced from 13 gears down to just 9 gears and a torque improvement of 40% is demonstrated via pulling on rubber bands and measuring the force using luggage scales. The torque detector is analyzed mathematically and the equations determining it's gear ratio behaviour are presented. Finally the overall improved automatic gearbox is tested and demonstrated to have a powerful second gear. -
Gearbox theory application - my attempts towards building an automatic gearbox for a car
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
This video applies gearbox, torque, and gearing ratio theory to design a prototype 2 speed automatic gearbox. First I describe the main components of an automatic gearbox, namely a gearing ratio selector and a torque detector. The ideal gear switch over torque point is described in terms of the PF motor torque and speed operating point, as well as the ideal gear switching ratio for the 2nd gear of the automatic gearbox. A technique for creating the 2nd gear is described by either adding to a differential by engaging a gear, or by subtracting by disengaging the gear. Issues around torque friction making it difficult to disengage a gear are mitigated by speeding up the gear switching axle to reduce torque. A torque detection method is shown using a differential for torque detection and driving a rotary catch back to the gear selector to change gears. A strategy is shown to reduce the torque and power loss due to the torque detector by placing it on a secondary path from the main power path. Finally an actual implementation of a 2 speed automatic gearbox is demonstrated and tested using a configurable torque generation mechanism using a series of clutch gears. -
Gears-efficient gearbox
technicmath posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
The idea of @nicjasno in for a gearbox can be improved as follows. There is no need for a 24 or 28 gear with clutch: the setup can be built as (two axles) 28-24-(20 with clutch)-clutch-(16 with clutch) (16 with clutch)-clutch-(20 with clutch)-24-28. For these gear combinations, a distance of 44/16=2.75 studs is desired. By using the above configuration, there is a distance of sqrt(2^2+2^2) or approximately 2.828 studs. This can be improved by xx -> 1 x 2 technic brick with 2 holes with axle at the left xxxx -> 1 x 4 technic brick with axle at the right. Then the distance is sqrt((3*2/5)^2+2.5^2) or approximately 2.773 studs, which is much closer to the desired 2.75 studs and then the gears run much smoother. -
Torque in Practice
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hi all, here's a video I did where I use a 10 level torque gadget I created to run some torque experiments to help improve my automatic gearbox designs. Hope you find it interesting. -
8 Speed Gearbox using just two levers/selectors - for @SNIPE
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Here I present an 8 speed gearbox that does the seemingly impossible - creating eight speeds using just two levers/selectors. Normally two selectors are used to create a 4 speed gearbox - however this design allows for 1 of 8 different speeds to be selected - thanks for the idea @SNIPE -
2 Speed Automatic Gearbox using a worm gear for torque detection (prototype)
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
This video present a 2 speed automatic gearbox based on using a worm gear for torque detection. The 2 speed gearbox works by using the linear counter-action force on the worm gear to connect a gear to create a second speed. This 2nd speed is added to the main drive path using a differential after being passed through a worm gear to prevent back rotation when the gear is disconnected. -
3 speed automatic gearbox fail. Do you have a solution?
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
This video presents a 3 speed automatic gearbox design that failed to work as expected. This design is based on an earlier design of a 2 speed smoothly switching automatic gearbox that worked very well. That gearbox was extended by adding another speed to the rotary catch selector however something happened I didn't expect. -
Efficient 4-speed gearbox
lmdesigner42 posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hi everyone. This is an efficient 4-speed gearbox design I came up with a while ago using the wave selector and new(ish) 20-tooth clutch gears. It is efficient since only 8 gears and 3 rotating shafts are required, which is near the minimum possible. The shafts in the image are as follows: Yellow - output Red - input Orange - shifter Black - extra, free-spinning All of the shafts go straight through the gearbox. The compact design is possible by meshing 16-tooth and 20-tooth clutch gears, which gives different ratios at each of the 4 clutch points. Unfortunately, the two shafts with driving rings need to be connected by another gear mesh (in this case 12:24) which results in out of order shifting with the wave selector. Gear 1 (1st) – 12:16 + 12:24 = 8/3 = 2.67:1 Gear 2 (3rd) – 12:20 = 5/3 = 1.67:1 Gear 3 (2nd) – 16:20 + 12:24 = 5/2 = 2.5:1 Gear 4 (4th) – 16:16 = 1:1 The shifting order issue could be corrected by using a mechanism shifting one driving ring back and forth and then the other, but that would take more space than the wave selector. The offset of one driving ring by one stud is handled by a sliding 16-tooth gear linking the lower driving ring with another 3 studs higher, putting it in the proper position to mesh with the wave selector. The extra free spinning shaft (black) is used to hold the third driving ring. The transmission fits into a small 9x7x6 box (not including the stepper) which can be easily connected to a chassis represented by the 5x7 frames. The below picture shows how small the core part of the gearbox is. In conclusion, the advantages of this gearbox include small size, few moving parts, and different ratios, while out-of-order shifting is a disadvantage. Comments and questions are welcome -
NEW 2 Speed Automatic gearbox - Smooth and Compact - has this been done before?
TechnicBrickPower posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hi All, I have created a new design for a 2 speed automatic gearbox that is both smoothly switching and compact. The best of both worlds. I don't know if my new (for me) technique has been used before so welcome your feedback.
