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Found 17 results

  1. I started this project because I wanted to share my experiences building various offroad models over the last decade. This topic is meant to guide the builders with comparisments, suggestion and best building practices, It is however not a place to find already finished and perfected designs - that's up to you. Various aspects of the design of the vehicles will be split into several subgroups and explained in details. 1. Number of wheels First thing we need to know is how many wheels our design will have. Most common setups are as following: 4x4 Setup Advantages: 1. The simplest and most widely setup 2. Having only 4 wheels means lower weight and higher performance 3. Higher manoeuverability 4. Simple suspension and driveline design Disadvantages: 1. With only 4 wheels the suspension has to be designed to be as flexible as possible to get the most out of the wheels 2. In a case of a mechanical failure of a single wheel, the whole model's performance is greatly affected 6x6 Setup with double rear axles Advantages: 1. Two rear axle provide more traction area, especially when going uphill 2. Usually 6x6 vehicles are longer than 4x4 and therefore less likely to tip over 3. Since the front and second axle are usually closer than in 4x4 setup, there is less ground clearance needed between them 4. Greater redundancy in a case of a mechanical failure Disadvantages: 1. Lower manoeuverability due to a longer wheelbase even with rear wheel steering 2. More complex driveline and suspension design is required 8x8 or more wheels setup Advantages: 1. Having 8 or more allows for much greater traction area 2. Ability to drive over ditches 3. Because wheels are usually much closer there is much less chances of getting stuck on top of an obstacle 4. Excellent redundancy in a case of a mechanical failure 5. Better weight distribution 6. Less suspension travel required per each wheel as with 4x4 or 6x6 and hence better stability Disadvantages: 1. Lower manoeuverability even with rear wheel steering 2. Powering 8 or more requires a very complex driveline 3. Depending on a driveline, combined torque required for powering all 8 wheels can destroy gears if a single wheel gets stuck 2. Type of wheels and tyres Now that we decided on how many wheels we want for our offroad beast, we have to look into what type of tyres and wheels we want to use. I will hereby cover only the bigger types of tyres and wheels. 1. 94.8x44R Advantages: 1. Low weight 2. Good thread design 3. Low rolling resistance Disadvantages: 1. Low traction, these tyres are prone to slip on the rim at high loads 2. Due to its rounded shape the tyres tend to slide off obstacles when crawling over them 2. 94.3x38R Advantages: 1. Low weight 2. Medium traction 3. Low rolling resistance 4. Realistic design and proportions Disadvantages: 1. Shallow thread pattern 2. These tyres are very hard and don't adjust to the terrain 3. 107x44R Advantages: 1. Low weight 2. Medium traction 3. Very deep thread 4. Currently largest tyres by diameter Disadvantages: 1. High rolling restistance and vibrations due to the thread pattern 2. These tyres are a bit hard and don't adjust to the terrain 4. Power Puller tyres Advantages: 1. High traction 2. Good thread 3. Largest Lego tyres ever produced 4. Deep wheel offset Disadvantages: 1. High weight 2. Hard to use, they require complex hub assemblies 3. Very rare and expensive 5. Outdoor challenger wheels Advantages: 1. Very high traction 2. Very good thread pattern 3. Deep wheel offset 4. Over 7 studs of space inside the wheel Disadvantages: 1. High weight 2. Hard to attach to the standard axles 3. They require a lot of torque to use them at their full potential. 6. Tumbler wheels Advantages: 1. Low weight 2. High traction 3. Very flexible Disadvantages: 1. Low thread pattern 2. Small size 3. Expensive For the 94.8x44R. 94.3x38R and 107x44R tyres we have a choice of two wheels: 1. Racing wheel large Advantages: 1. Good mounting option with axlehole and pinhole 2. Available in multiple colours 3. Cheap Disadvantages: 1. No inside wheel offset means steering pivot point can't be placed inside the wheel. 1. Futuristic wheel Advantages: 1. Deep wheel offset allows us to place steering pivot point inside or closer to the wheel than racing wheel large 2. Slightly larger wheel size stops the 94.8x44R tyre from slipping on the rim Disadvantages: 1. Limited mounting options, with only one axlehole 2. Hard to find 3. Hubs Now that we have our wheels and tyres we need a way to mount and power them. Here are the most common currently available options: 1. New standard ungeared CV hubs These hubs are usually driven by the CV joint counterpart which pops inside Advantages: 1. Low steering pivot offset - usually at the edge of the tyre: 2. Firm wheel mounting 3. Readily available, easy to use and to build on. Disadvantages: 1. Low operating angle - the CV joint can operate to a maximum of about 30 degrees, which limits steering angle. 2. Very low torque transfer - the CV joints are prone to deforming and popping out even with low torque applies to them 3. Low ground clearance 2. Old ungeared CV hubs Advantages: 1. Low steering pivot offset - usually at the edge of the tyre 2. Firm wheel mounting 3. Better ground clearance than newer hubs Disadvantages: 1. Very low operating angle - the CV joint can operate to a maximum of about 25 degrees, which limits steering angle. 2. Very low torque transfer - the CV joints are prone to deforming and popping out even with low torque applies to them 3. Hard to find and expensive 4. No other mounting points than 4 ball joints 3. Built cardan ungeared hubs Example of a hub using a cardan joint to directly transfer the power to the wheel Advantages: 1. Low steering pivot offset - usually at the edge of the tyre 2. Easy to build 3. Can transfer higher torque than a CV joint 4. Higher steering angle Disadvantages: 1. Mounting relies only on the axle and is not as firm as standard hubs 2. Not capable of transferring high torque to the wheels 3. Low ground clearance 4. Standard portal hubs Advantages: 1. Easy to use and to build on. 2. Can transfer very high torque to the wheels when using 8z and 24Z gear combination 3. High steering angle 4. High ground clearance 5. Firm wheel mounting Disadvantages: 1. Very high steering pivot offset - requires stronger steering mechanisms and more fender space for wheel to swing 5. Built portal hubs Advantages: 1. Easy to build. 2. Can transfer very high torque to the wheels when using 8z and 24Z gear combination 3. High steering angle 4. Higher ground clearance than standard portal hubs 5. Low steering pivot offset when using futuristic wheels Disadvantages: 1. Wheels are mounted and held only by one axle, not as firm as standard hubs 2. Hub relies on friction of the components to keep it together, which can slide apart after prolonged use 6. Built planetary hub Advantages: 1. Highest gear ratio of all other hubs, 1:4 2. Firm wheel mounting when using futuristic of power puller wheels 3. High steering angle 4. Lower steering offset than standard portal hubs Disadvantages: 1. Requires old turntable, futuristic or power puller wheels for best results - all are hard to find 2. High number of moving gears 3. Least efficient due to the high friction caused by the large surface contact area and number of moving gears 4. Suspension Suspension is the mechanism that will keep our model's wheels in contact to the ground and will be supporting most of its weight. Most of the designs cover 4x4's Following factors determine the type of suspension system we will use: 1. Weight of the model - The heavier the model, the stronger the suspension components have to be 2. Speed - Faster models require more responsive suspension systems with low unsprung weight 3. Flexibility - The higher the obstacles you want to climb over the more flex and/or wheel travel suspension has to provide 1. No suspension I have yet to see and offroad vehicle without any type of suspension (except for maybe 42070, 42081 and 42082), but I will list my opinion regardless: Advantages: 1. Simple design - having no suspension simplifies our design...and that's about it Disadvantages: 1. No flex over terrain means, there are only 3 wheels at once touching the ground 2. Low stability 3. Poor weight distribution 4. No shock absorption at high speeds 2. Pendular suspension This is the simplest suspension you can put on your vehicle. It basically means one or more of your axles are free to swing about. When using this suspension I suggest using the small turntable where drive axle enters the axle. This will keep the drive axle from carrying the weight of the model, which causes unnecessary friction. 42030 is a typical example of this suspension system. Advantages: 1. Simple, robust design 2. Using this suspension on both axles can give the model very high flexibility 3. If there are no springs used, the model can have perfect weight distribution on left and right wheel Disadvantages: 1. Large unsprung weight, poor responsivness at high speeds 2. No shock absorption means this suspension is not suitable for high speeds 2. When using on one axle, the stability of the whole model relies on the unsuspended axle. 3. When using pendular suspension on both axles springs or a transfer mechanism are required to keep the model upright 3. Single torque tube suspension This suspension became available with the release of the 8110 Unimog. Best examples of this suspension are 8110, 9398 and 41999. It is the simplest suspension which also allows for vertical suspension movement. Advantages: 1. Simple, robust design 2. Universal joints can be placed inside the ball joint, allowing power to be transferred to the axle 3. Easy to implement Disadvantages: 1. Large unsprung weight, poor responsivness at high speeds 2. Axle requires a some kind of a linkage system to keep it cenetred (panhard or parallel links as seen above). 3. Using this suspension on the front axle usually results in negative caster angle which causes higher rolling resistance 4. When used on rear drive axle, the suspension has the tendency to cause oscillate, especially with soft suspension and high power 4. Hard to connect springs to the chassis 4. Double torque tube suspension This is an evolution of the single torque tube suspension, which uses two ball joints to drive each wheel side respectively. It is my own original idea. Advantages: 1. Simple, robust design 2. Universal joints can be placed inside the ball joint, allowing power to be transferred to the axle 3. Easy to implement 4. Self-cenetring, since axles are connected in the center there is no need for linkages to center it 5. Can carry power to each wheel side independently 6. Drive torque compensation Disadvantages: 1. Large unsprung weight, poor responsivness at high speeds 2. Using this suspension on the front axle usually results in negative caster angle which causes higher rolling resistance 3. When used on rear drive axle, the suspension has the tendency to cause oscillate, especially with soft suspension and high power 4. Hard to connect springs to the chassis 5. Parallel floating axle This suspension uses linkages which keep the axle parallel to the chassis of the model. For best functionality and reliability the lengths of all links and that of the double cardan joint should be equal. Also all the linkages and drive axles should be parallel. Advantages: 1. Keeping the axle parallel to the chassis reduces the oscillations effect 2. Better responsivness compared to the torque tubes 3. Neutral caster angle when used on front axles. 4. Self cenetring when using A arm as upper link or 4 link setup 5. Can be configured to carry power to each wheel side independently 6. If configured to carry power to each wheel side independently the drive torque can be compensated. 7. Easy to connect spring to the chassis Disadvantages: 1. High unsprung weight, less responsive at high speeds 2. Increased mechanical complexity, double cardan joints required to carry the power to the axle 6. Half axle independent suspension This is the simplest independent suspension you can build. Best example of such suspension are Tatra and Pinzgauer trucks. Advantages: 1. Independent suspension with low unspring weight, suitable for high speed 2. Robust design with low number of moving parts 3. Easy to connect spring to the chassis Disadvantages: 1. Changes of the caster angle as the wheels travel up and down 2. Hard to implement a drive system that does not carry the weight of the vehicle 3. Hard to implement steering system 4. Wheels tend to drag sideways on the ground when suspension travels up and down, reducing efficiency 7. Trailing arm parallel independent suspension Personally I have not used this suspension yet, but I did use a normal trailing arm suspension which does not keep the hubs parallel. Normal trailing arm suspension which does not keep the hubs parallel acts similarly to torque tube suspension. For the prallel version of the trailing suspension I imagine the following: Advantages: 1. Independent suspension with low unspring weight, suitable for high speed 2. Robust design with low number of moving parts 3. Long links allow for high suspension travel 4. Very easy to connect spring to the chassis 5. Can be configured to carry power to each wheel side independently Disadvantages: 1. Hard to keep the wheels from sagging under the weight of the model. 2. Difficult to transfer power to the wheels 8. Double wishbone suspension This suspension uses two A-shaped arms to keep the wheel hubs in place. As of late it's my favourite suspension system due to: Advantages: 1. Independent suspension with low unspring weight, suitable for high speed 2. Very customizable design with lots of adjustable characteristics (suspension arm lengths, caster angle, camber angle, steering geometries) 3. When build correctly it is far more robust than live axle suspension 4. Increased ground clearance compared to live axle suspension, especially when used with portal hubs 5. Can be configured to carry power to each wheel side independently 6. Extremely easy mounting of springs 7. Very stable compared to live axles 8. Frame holding the suspension can be part of the chassis, therebye lowering the center of gravity Disadvantages: 1. More moving parts as live axle suspension, increased mechanical complexity 2. Limited wheel travel - Lego wishbones allow a max. of around 25 degrees of suspension angle 9. Multi-link suspension To be updated when I build my first multi-link offroad suspension. I can assume the following characteristics: 1. Independent suspension with low unspuing weight, suitable for high speed 2. Extremely customizable design with lots of adjustable charactersitics (suspension arm lengths, caster angle, camber angle, steering geometries, virtual pivot point) 3. Large steering pivot point compensation 4. Increased ground clearance compared to live axle suspension, especially when used with portal hubs 5. Can be configured to carry power to each wheel side independently 6. Very stable compared to live axles 7. Frame holding the suspension can be part of the chassis, thereby lowering the center of gravity Disadvantages: 1. Very high amount of moving parts, increased mechanical complexity 2. Limited wheel travel - Lego wishbones allow a max. of around 25 degrees of suspension angle 3. Hard to connect springs to the chassis 10. Spring types Listed below are the most common types of springs available: 6.5L Soft shock absorber Advantages: 1. Small, easy to implement Disadvantages: 1. One stud of suspension travel 2. Low spring rate, can't support heavy models 6.5L Hard shock absorber 1. Small, easy to implement 2. High spring rate, can support heavy models Disadvantages: 1. One stud of suspension travel 9L soft shock absorber When using 9L shock absorbers I suggest you do not use the default offset upper attachment point, but use an in-line attachment point instead. This will reduce the friction and allow for better high speed performance Example: Advantages: 1. Two studs of suspension travel 2. More attachment possibilities than 6.5 L shock absorber Disadvantages: 1. Default attachment points create friction 2. Low spring rate, can't support heavy models 9L hard shock absorber Advantages: 1. Two studs of suspension travel 2. More attachment possibilities than 6.5 L shock absorber 3. High spring rate, can support heavy models Disadvantages: 1. Default attachment points create friction 2. Rare and expensive 11. Attaching springs to live axles If we start with basics, the first things we have to check is how position of springs affects suspension of live axles. The closer you place the springs together, the more flex the suspension will have, but it will also be less stable: I suggest you to keep springs at a distance of around 1/2 of the total model width. When placing springs you should keep them in-line with the wheel bearing in order to reduce friction. First example of bad spring placements: And example of good spring placement: When using multiple springs make sure to place them symmetrically centrred to the wheel hub: When attaching springs to torque tube suspension, you have to allow springs to tilt in two planes: You can also attach the springs to the suspension links to increase suspension travel. This technique is especially common on Trophy Trucks: 12. Attaching springs to independent suspension Independent suspension allows for much more flexible spring placement. Generally the closer you attach the spring to the main suspension arm pivot, the higher spring travel you get, but lower suspension force. Examples going from the hardest suspension with low travel to the softest with high travel: You can also attach springs inside the suspension arms: Or horizontally: As with the live axles make sure springs are in the center of the wishbones. Example of good placements: And an example of bad spring placement, which causes excessive friction and suspension binding: 5. Steering Steering is the system which allows our model to change direction. Generally there are two types of steering system used: 1. Skid steering Advantages: 1. Very simple to implement and control with two separate motors for left and right sided wheels. 2. Does not require a dedicated steering motor Disadvantages: 1. Not efficient, since wheels have to skid to steer 2. Power had to be reduced or even reversed in order to steer. 3. Not very accurate 4. Not very effective offroad 2. Classical steering with steerable wheels Advantages: 1. Efficient, with minimum loss of speed 2. Accurate 3. Does not reduce the power of the drive motors 4. Can be used in front, rear or all axles for tight steering radius or crab steering 5. Effective offroad Disadvantages: 1. Requires more complex hub assemblies 2. For best steering accuracy you need a dedicated servo motor. Examples of a simple classical steering system for live axles 1. Parallel steering system for live axles Here both hubs are always parallel. Position of the steering in the front or rear rack has no affect on the steering. Advantages: 1. Very simple and robust 2. Easy to build Disadvantages: 1. No Ackermann steering geometry 2. Steering rack moves inwards as it steers, requiring more space. 2. Ackermann steering system for live axles This system allows the hubs to steer at different rates. The steering arms are offset inside so they form a virtual steering point where at the point where lines meet. Advantages: 1. Better steering performance Disadvantages: 1. More complex assembly 2. Steering rack moves inwards as it steers, requiring more space. 3. Steering system with diagonal linkages This system acts similar as Ackermann steering system by using diagonal steering links. Advantages: 1. Better steering performance 2. Steering rack only has to move in one direction without sideways movements 3. Can be configured to be used in front or the rear of the axle. Disadvantages: 1. More complex assembly 4. Simple steering system for independent suspension 1. Very simple and robust 2. Easy to build 3. Can be even more robust when using double steering racks and links 4. Steering rack only has to move in one direction without sideways movements Disadvantages: 1. No Ackermann steering geometry 5. Ackermann steering system for independent suspension Advantages: 1. Better steering performance 2. Steering rack only has to move in one direction without sideways movements Disadvantages: 1. More complex assembly, less robust. 3. General steering tips 1. When using independent suspension always make sure your links are paralel to the suspension arms, otherwise you may end up with wheels which are not parallel and are causing excessive friction: 2. When using standard portal hubs make sure your steering system is robust enough to deal with the forces generated by wheel driving into obstacles. 3. If possible use servo motors which allow for high steering precision and return to center. They are especially useful at high speed models. 4. Most efficient way to steer the wheels is using the steering racks. 5. Build axles in such way they have positive caster angle, example for direction of travel from right to left. This will self-center your wheels and reduce rolling resistance. 6. Drivelines Drivelines are the responsible for transferring the power from the motors to the wheels. There are various drivelines you can build, here I listed few with their characteristics: Driveline types 1. Permanent 4x4 Advantages: 1. Simple, centralized, low mechanical complexity 2. Wheels are always powered, great offroad performance 3. Light weight Disadvantages: 1. Poor steering radius 2. Tyres have to skid when steering, lowering efficiency of the model 2. 4x4 with open differentials Typical example of this driveline is 42070 Advantages: 1. Differentials allow the wheels to so spin at different rates when steering 2. Very efficient since wheels don't have to skid when steering Disadvantages: 1. If one wheel loses traction, all the power is transfereed to it, poor offroad performance 3. 4x4 with lockable differentials Advantages: 1. Differentials allow the wheels to so spin at different rates when steering 2. Very efficient since wheels don't have to skid when steering 3. All differentials can be locked, so wheels are powered for great offroad performance Disadvantages: 1. Higher mechanical complexity 2. Dedicated motor is required to actuate differential locks, higher weight 4. Axle mounted motors Typical example of this driveline are 9398 and 41999. Advantages: 1. Differentials allow the wheels to so spin at different rates when steering 2. Very efficient since wheels don't have to skid when steering 3. If one wheel gets off the ground the second axle can still pull/push the model. Disadvantages: 1. Higher mechanical complexity 2. Usually the rear axle motor is more loaded than the front, especially when climbing uphill, the motors can't "help" each other. 3. Worse offroad performance than permanent 4x4 5. H drive: This is my favourite driveline due to the following reasons: Advantages: 1. Motors allow the wheels to so spin at different rates when steering 2. Model can skid steer 3. Very efficient since wheels don't have to skid when steering normally 4. Having 2 drivelines allows you to carry more torque to the wheels 5. Redundancy, even if one drive fails the model can still move 6. Wheels are always powered, great offroad performance Disadvantages: 1. Higher mechanical complexity 2. Slightly higher weight 6. Wheel motor drive Each motor powers a wheel independently. Advantages: 1. Motors allow the wheels to so spin at different rates when steering 2. Model can skid steer 3. Very efficient since wheels don't have to skid when steering normally 4. Redundancy, even if one or more motors fails the model can still move 6. Lower mechanical complexity Disadvantages: 1. Motors can't "help" each other 2. Higher weight due to a higher motor count Transferring power axially When transferring power via axles, you can reduce the flex by using connectors instead of simple "bare" axle: Use axles with stops to prevent them from sliding out of gears: Where possible always brace tooth gears from both sides: Transferring power at an angle Where pairs of U joints are used, make sure to align them to eliminate vibrations: Brick built CV joint which can transfer high torque at over 30 degrees angle Brick built cardan joint which can transfer extremely high torque up to 15 degrees angle Brick built flexible drive which can transfer medium high torque, extract and retract, suitable for low angles Transferring power perpendicularly The following perpendicular gearboxes are the best suitable for transferring high torque Avoid knob and worm gears, because they waste energy Gearboxes In my models I generally use the following gearboxes: 1:3 differential gearbox Advantages: 1. Very high gear ratio between low and high gear, 1:3 2. Capable of transferring high torque 3. Very efficient since only 2 gears are used at any time Disadvantages: 1. Takes a lot of space 2. This gearbox requires a good housing to brace the gears properly Compact two speed gearbox Advantages: 1. High gear ratio between low and high gear, 1:2,77 2. Capable of transferring high torque 3. Very efficient since only 2 gears are used at any time 4. Very compact design Disadvantages: 1. Requires two of the rare 20 tooth clutch gears 2. More complex shifter assembly. Diagonal gearbox Advantages: 1. High number of gears 2. High gear ratio possible, over 4:1 2. Capable of transferring high torque 3. Very efficient since only 2 gears are used at any time Disadvantages: 1. Takes a lot of space 2. Input and output axles are not parallel. 3. A complex shifting assembly is required for sequential operation. Driveline effect on suspension Transferring torque on the wheels can affect the suspension, especially when live axles are used. The following photo shows how the torque causes one side of the axle to push down and the other to lift up: In order to minimize this effect I suggest the following: 1. Make sure to have most if not all the downgearing inside the axles, so you do not need high torque going to the axles. 2. Make sure your models have a low center of gravity 3. You can eliminate this effect by using two counte rotating axles which cancel each other's torque, example below: 7. Motors and control Following are the most common types of motors used for Lego models. You can find more info here: http://www.philohome.com/motors/motorcomp.htm My personal favourites are L and RC motors due to the balanced output speed to torque ration and great mounting options. 1. PF-M Advantages: 1. High speed output 2. Smallest available motor 3. Cheap and available Disadvantages: 1. Low torque 2. Poor mounting options 2. PF-L Advantages: 1. High speed output 2. High torque 3. Cheap and available 4. Great mounting options Disadvantages: 1. Odd shape 3. PF-XL Advantages: 1. Very high torque 3. Cheap and available 4. Good mounting options Disadvantages: 1. Slow speed output 2. Large form factor 4. PF-Servo Advantages: 1. Very high torque 2. Very precise output with 15 positions 3. Good mounting options Disadvantages: 1. Slow speed output 2. Output axle can move a max of 180 degrees 3. Large form factor 4. Hard to find 5. 9V-RC motor Advantages: 1. Most oowerful Lego motor 2. Very high speed output 3. Good mounting options 4. Two output axles with different gearing ratios 5. Drive axles can pass through the motor Disadvantages: 1. Low output torque 2. Low efficiency 3. Power hungry 4. Odd form factor 5. Hard to find and expensive Power options 1. PF - AA battery box Advantages: 1. High capacity 2. Good mounting options 3. Works with rechargeable batteries, but with lower performance 4. Cheap and easy to find Disadvantages: 1. 750mA current limit - not enough to fully power RC motor 2. Heavy 3. Has to be removed and opened to replace batteries 4. Wasteful 5. Odd form factor 2. PF - LiPo battery box Advantages: 1. Small form factor 2. Light weight 3. Easy to recharge Disadvantages: 1. 750mA current limit - not enough to fully power RC motor 2. Low capacity 3. Studded design 4. Expensive and hard to find 3. RC control unit Advantages: 1. No current limit - can power 2RC motors at once 2. 3 Power levels 3. Has integrated steering output with 7 positions 4. Good mounting options 5. Easy battery replacement 6. Radio based control Disadvantages: 1. Poor quality, prone to breaking 2. Limited angle (45 degrees) and torque from the steering output 3. Has to be removed and opened to replace batteries 4. Very large form factor 5. Expensive and hard to find 6. Heavy 7. Required dedicated antennas and remote Control options 1. PF receiver and controller Advantages: 1. Receiver is easy to integrate into the model 2. Controllers have physical feedback 3. Cheap and easy to find Disadvantages: 1. IR based, low range, useless outside 2. Lack of PWM motor control, unless using train controller which is awkward to use 3. Odd form factor for use with steering 2. RC control unit See above 3. Third party options such as BuWizz and Sbrick Advantages: 1. Smaller form factors, easy to integrate into model 2. More outputs than PF system 3. Smooth control of motors 4. High range thanks to Bluetooth control 5. Higher power available with BuWizz 6. Customizable profiles Disadvantages: 1. Smart device is required 2. No physical feedback 3. Sbrick is limited by PF battery box 4. Price 8. Chassis Chasis is the backbone of your model which olds everything together. For chassis I suggest you to use the following components in order to make it strong and robust enough to deal with the stresses involved when crawling or driving at high speed: Some flex in the chassis might be a good thing to improve offroad capability, but only if id does not affect the driveline and cause friction on the drive axles. Remeember to use diagonal support, since triangles are the strongest shapes. You can also use panels and motors as structural support. Interlocking your chassis will keep it from slipping apart. For good examples of chassis designs I suggest you check the instructions for 9398 and 42083.
  2. Zerobricks

    Leopard 4x4

    After a few month break it's time to get back to Lego and Eurobricks, and why not do it in style I give you the leopard 4x4: The model is a combination of the following ideas and concepts: Quite some time ago I came up with double torque tube suspension idea and now it was time to use it in a real model Claas tyres were an obvious choice due to their agressive profile and massive size. With the release of the 42069 set, I was finally able to build a model with a unique and striking color combination The final model took me some 12 hours to build and the features are as following: - Powered by 4 RC motors and 2 Buwizz - Double torque tube suspension - Independent dual drivelines - Dual servo steering gemoetry - Working winch - Working lights - Openable doors - Openable hood - Openable and removable rear cover Specs: - Width: 24 cm - Height: 24 cm - Weight: 1600 grams - Final gear ratio: 1:5 from outermost RC motor output - Total power: ~60 watts Now onto the photos: The rear trunk can be opened: There is barely enough room left for seats in the interior. Notice the different springs used to potimise suspension. The before mentioned springs give the model excellent flex: There are two servo motors used in order to keep the steering system as stiff and strong as possible: Under the hood there is a hidden winch, which is strong enough to lift the car: And the final, most important photo. Notice how the left and right side wheel drive axles use different colored joiners and bushes: And finally there is a video of the model in action: Safe to say the combiantion of the four RC motors and two Buwizzes with a low gear combiantion of 1:5 results in a model with impressive performance. As seen in the video Leopard can wheelspin all 4 wheels when accelerating on flat surface, which is a first for any of my Lego offroaders. Dual servo motors provide massive steering power and rigidity and allow the wheels to be steered into obstacles with ease. Only downside to the model is it's slightly high center of gravity cause by all the added panels and detailing. P.S. It feels good to be back
  3. sander1992

    MOC: The Doctor vs. The Daleks

    Hi all, I wanted to create a scene with Doctor Who and I wanted to experiment with floor techniques. The Doctor found out that the Daleks have created a portal to travel through time. The Daleks want to go back to the Time War to save their race from extinction. The Doctor have three Daleks in his vision, but he is not aware there is a fourth Dalek. Clara keep a low profile and stays with the TARDIS. No one have noticed that Weeping Angels are present and absorbing energy from the portal. For more pictures you can go to my Flickr album. Doctor Who Comments and questions are welcome. Sander
  4. The_Icestorm

    [EV3] GLaDOS

    This is a recreation of the robot character GLaDOS from the game 'Portal', using Technic and Mindstorms. Just to answer a question some of you may have: Why Mindstorms? Why not PF? Well for a start, I don't own that many PF motors (only got 2 medium motors and 1 XL motor), and secondly, I don't own any PF IR receivers or remotes. The mindstorms kit has its own IR sensor and remote, so I used that. Functions: 1. Head elevation controlled by EV3 large motor 2. Head rotation controlled by EV3 medium motor 3. Body elevation controlled by EV3 large motor 4. Body rotation controlled by EV3 medium motor These may not be very many functions, but they allow for most of GLaDOS's movement seen in the actual game. The range of movement is quite reasonable. Regarding aesthetics, I don't own a lot of LEGO pieces, so the model may look a bit incomplete or strange in some places. But I think I did an OK job with what I had to work with, especially the head. Some more images: Video: More info about the robot can be found here: https://www.us.lego.com/en-us/mindstorms/community/robot?projectid=d1208d08-db8f-421c-9aa7-5f618912d7b0
  5. I decided to open a seperate topic for this beast. Inspired by Letsbuild's idea to crawlify a Lego set, i decided to go full crazy and try to upgrade the biggest, heaviest and most orange set to date, Porsche 911 GT3 RS. First thing I built was the front axle, which uses the H frame as a placeholder for bewel gear, so there it no possible way of them to slip: Those with sharp eyes may notice the gears are not aligned, this was done in LDD development mode, more info soon The drive than goes directly to portal hubs with 1:3 gear ratio, giving the model 1:5 gear ratio on each wheel. Front axle also has a servo motor which steers the wheels and powers the Porsche's original steering wheel via a ball joint Rear axle powers the Porsche's gearbox via a couple of clutch gears in order to allow different motor speeds when steering or skid steering - Yes, this 4 kilogram heavy model can even skid steer thanks to its independent motor control. Here is the end result As with the original set, I kept the rear axle 2 studs wider than the front: For suspension I used 4 hard springs, which are hald compressed thanks to the model's immense weight. Due to the porsche's wide chassis springs are quite far apart, so the flex angle is not really big, but on the other hand that makes the model much more stable. Performance wise the crawler works very good, despite its massive weight, so far I had no broke U joints or gears and it has enough torque to skid its wheels on hard surface. Expect more pictures soon and a video soon.
  6. Agent Kallus

    MOC: The new companion

    I built a Tardis interior but I wanted to put a new spin on it so.... Presenting Time machine DIY with portals. Chell's not using the official legs or gun cause I haven't gotten the portal dimensions pack yet but I got the torso and head separately.
  7. Some time ago i posted a B-model of palace cinema which i called caesar cinema. I wassn't totaly happy about it and i got some other ideas for modulars i wanted to build. and so i created the new Caesar Cinema with next to it a sneaker store called "SNKR" I am a huge sneaker fan. (i have 25 pair of nike's and Jordans) so i really wanted to make a sneakerstore modular. an this is what i came up with: I figured that the best pieces to represent sneakers would be the up side down 1x1 plate and the 1x1 slope Some limited golden and bleu sneakers behind glass Upstairs there is storage for some shoeboxes and... a companion cube?? and a locked door... To open the door, some one already got to the 2nd floor where some test must be done. but if you complete the test, the door will be opened and there wil be cake! CAKE!! so yes i am also a portal fan! LEGO, PORTAL and Sneakers all in one modular!! (have you figured out how to open the door yet?) The cinema is mostly build form the pieces from palace cinema, the City Pizza truck and some extra red parts for the theater room. in the entrance room there is a City Pizza where you can buy and eat pizza, but also drinks and popcorn for the movies, and a desk to buy your movie tickets. don't be afraid by the life size ET, Egyptian and BRICK SEPARATOR! and here it is in my city
  8. The Chosen One

    Handheld Portal Device

    "Very good! You are now in possession of the Aperture Science Handheld Portal Device." — GLaDOS from Portal. Hope you enjoy, any comments are welcome!
  9. As a huge fan of Terra Nova and Stargate I decided it's time to become MacGyver and produce round portal/gate.I had a lot of spare round tiles the swirl wasn't a problem. The round design which hide the swirl from the side was much more tricky. The gate is 3 studs wide and it's double sided. One side consist the entrance with the marking of the destination. Full Flickr Gallery
  10. Hello, and, welcome to the Aperture Science Computer-Aided Enrichment Center Eurobricks LEGO Media and Gaming Forum. You will be reading a review of 71203 Level Pack: Portal 2. I am authorised to inform you that there will be cake at the end. The Cake is a Lie! First we'll take a look at the LEGO Shop blurb. Front of the trapezoid box/carton/swing pack we have our figure and the two re-build-able vehicles. As with the other packs, it is an iconic pair. One sentry turrent and a weighted companion cube. Though, I would have loved a core of some kind. The side on view is an action shot of Chell. The opposite side has warning information on the "tags"; avoid getting them wet, magnets etc. These were murder to photograph, the angle of the box made it next to impossible for a good shot! The back of the box shows off the three things your "vehicles" can become alongside the warning information and age ratings. Plus the now very familiar Dimensions graphic. Inside the box, two bags of parts and the most pointless instruction manual (MPIM) It tells you how to build Chell and then directs you to the game. The extra pages are adverts and ticksheets of what to collect, much like all the others. Of course, this is the aim of LEGO Dimensions so I can't fault it too much. Just be warned that you'll need to look online if you want to have any of the level or character packs simply for the builds. Onwards then, to the builds themselves. Here we have what is probably the biggest attraction for gamers and AFOLs alike; Chell herself in official LEGO Minifigure form. Aperture vest, long fall boots, portal gun and all. She's about as talkative as the real deal too! One whole new figure, a printed tag and the lovely portal gun. The gun is a two parter, a rubber weapon with the siren popped in. The rubber makes it a little awkward to get into a figure hand and to pose it once it is in there. Though it is a lovely crisply moulded part, well designed and printed too. Yes, it is a render, but it shows off the part better than my camera can! Chell is fun to play as. Bringing along the Portal Gun that can be used, of course, to create portals. In the regular game environment there are white surfaces not dissimilar to the Aperture Test Chamber walls. They are dotted around the levels or can be built from revealed LEGO parts when you smash things. As expected, they help you access areas of the game to find gold bricks and mini-kits. Here is the official video. Companion Cube The Companion cube in its basic form. The cube itself is made up of printed tiles, five of them, no sixth, so you'll have to pick one more up for a more detailed version of the cube. It would have been great to have something more like the actual cube or some of the fan efforts out there, but of course the designers had to make it into two other things too. Hence all the extra goings-on underneath. Not the worst offender of the vehicles in Dimesions though. Aren't the printed tiles great! Laser Deflector Cube The "Laser Deflector" mode Cube uses all the parts from the regular cube and looks a little nifty. It can't help but look a little odd, but so did the first basic mode. As can be inferred from the name, it deflects lasers. Useful to solve certain puzzles. The Gold Heart Emitter This is the weirdest of the builds, but there is little one can do with a cube isn't there? Again, it does what it says on the can. The Turret Sentry Turret The regular turret is rather spiffy. Looking pretty much like the video game source but rendered in our favourite blocky medium. The turret provides lasers, which in LEGO games are used to damage gold obstacles in levels. Also useful when there are a lot of foes to battle. Turret Striker The turret provides a lot more to work with. So this variation looks much better than the companion cube remixes. More hefty and speedier than the Sentry Turret. Also, more "dakka" to play with in the game is always fun. Flying Turret Carrier This version of the turret is wider than the others, extra width for menacing placement of weapon's systems. It flies, this is helpful in games of course, allowing non-flying characters to fly. The Game It was a joy to play Portal in LEGO game form. Just too much fun for nerdy me! All the expected jokes and original voice casting. There's even a song! I don't want to spoil much more really. Just be assured: If you are a gaming fan, a Portal fan and a LEGO fan this is worth it. Conclusion So, if a visit to a LEGO version of the Aperture Science Computer Aided Enrichment Lab is exactly your cup of tea, this is excellent. If you have a Portal fan in your life, the LEGO figures and models are great novelty items in their out-of-box form (you can find instructions online, most helpfully). The game and the toy justify the price point, though it might be a little pricey if you just want the LEGO. However that is to be expected, you can't exactly compare this to regular LEGO sets. Also merchandise for games (like figures and vehicles) do have a similar price when cost of three items are added together. Thanks to TLG for giving me the opportunity to play with and review their exciting new product. Set Supplied by The LEGO Group.
  11. So as soon as I heard about the new contest, I knew I wanted a different crane as the normal mobile ones... A quick google search for off road crane inspired me as soon as I saw this picture: More info here: http://www.ww.mainpu...ifting/6196.htm Yes, its an 8x8 off road crane with massive tyres, suspension and what-not. After fiddling in LDD and real life I came up with front suspension: As you can see, its inspired by 42043's rear axle assemby, but upgraded: - with all wheel drive - portal axles, - improved steering system - longer, harder shock absorbers - can carry A LOT of weight The steering system is my own idea (as far as i know), by using different handle and steering arms length I get different steering angles: Another thing I built are the outriggers. Because this is an off road truck, the outriggers need to be high enough not to bump into terrain, yet they have to lower enough to do their job. This is why they extend at an angle: The outriggers may look rather thin and weak, but the fact is the 13L beam and 13L rack are in a sandwich which cannot be seperated, so they can carry lot of weight, as long as you dont bend them sideways too much. Here is how the front suspension and outriggers look like together: And I already started working on the rear axle... You can see its simpler than front axle, it has more support, and its very solid. There are a total of 10 points holding the rear axle assembly: - 4x Springs - 4x Longitudal links with rubber bricks with limited longitudal movement (you need a bit of movement in order for axles to flex sideways) - 2x Panhard links which keep the axles from loosely moving sideways Also notice the drive axle on the left, thats for the fake motor drive. More info soon...
  12. LegoPercyJ

    (MOC) Portal Turret

    "Hello there..."
  13. Lego Junkie

    Portal: Still Alive. (MOC)

    https://c1.staticflickr.com/9/8830/18236072416_90f121ae07_h.jpg The ashes stir once again...
  14. With the hubless wheel post in the back of my mind and some 56x28 ZR Street tires on my table next to some old-style track links, something clicked in my head. 22 of the track links fit perfectly in the 56x28 tires. More interestingly, if you put 4L tiles or plates on alternating links, they also fit the inside of the Unimog tire. Of course you'll need more than 22 - probably between 40 and 50 - to fill the Unimog tire. The tracks can be driven by spur gears, so you could make a planetary reduction hub which could also be a portal hub. I don't plan to make any large trucks any time soon, but figured I'd post this in case it's useful to those who build trial trucks and other large vehicles.
  15. Hello everyone! Kooberz here. Recently, I was asked to create an interview/tour interview for the Red vs Blue Uk event held on August 2-4 in Leicester. They provided the questions, and I did my best to answer them in the best way, and present some of my best and previously unseen work. I hope you like it! Also just released, is a full tutorial on how to make my version of GLaDOS from Lego Portal 2 Part 1.
  16. Hello everyone, I will not pull the entry, so I'll start with the MOC.In this model, the main character is a little Pteranodon, escape the jaws of a giant snake. The portal opens at a time when the hunter caught his prey. The portal is made mainly in bright green and black colors. Other images: http://fotki.yandex....659376/?page=18 Thanks for watching!
  17. bricked one

    Portal stuff

    These have been sitting around for quite awhile so I thought I'd share them with you guys. Thanks for visiting!