JLiu15

Eurobricks Knights
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About JLiu15

  • Birthday 12/01/2000

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    Technic
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    42158

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    Male
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    Iowa

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    USA

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  1. Wow, this build looks amazing so far. I can't wait to see what it looks like when the rear body panels are finished. I love the red/yellow scheme and the large water cannon on top. It reminds me of my Airport Crash Tender MOC from 2017, but your model looks even bigger. What's the tire/rim combo you're using for the model?
  2. I've considered using something custom like BrickScreens by Brickstuff, but I don't think they make any in the dimensions of a typical bus destination sign (unless maybe I put a bunch of smaller ones next to each other).
  3. I've considered that but realism is a major consideration for my bus models so if the real bus doesn't use planetary hubs I probably won't use them either, although they really do provide a huge amount of gear reduction (over 5:1 I think). Thanks! I like this approach as it allows for all the Technic functions while giving it a detailed finish with System pieces. It took me a while to get the right geometry for the door mechanism, but in the end it worked flawlessly and is one of my favorite parts about this MOC.
  4. Thanks! I'm definitely thinking of using hubs for my next bus model of this size since the weight of the model really added up. I'll probably use two drive motors too. My initial design actually had the yellow differential from the Ferrari Daytona set, but as the weight of the model increased I had to find gearing down somewhere and changing the gear reduction at the differential from 14:22 to 12:28 seemed to be a good choice. Thank you! I'm really satisfied with how the looks of the model turned out in the end. Using System pieces for the bodywork really helps to capture all the details.
  5. Model of a New Jersey Transit 2020 MCI D4500CT commuter coach. Features motorized drive, steering, full suspension, working passenger door, removable Cummins engine model, and changeable destination signs. Functions/features: Drive Steering Full suspension Working passenger door Removable Cummins engine model with moving pistons Changeable destination signs In 2016, a new order of MCI D4500CT commuter coaches began slowly being introduced to the New Jersey Transit fleet to replace the aging D4000 and D4500 coaches built in the early 2000s. Deliveries would occur until 2022, and over 1200 buses were ordered for New Jersey Transit as well as private carriers. The buses saw a number of minor changes throughout the delivery years, most notably a change from the Cummins ISX-12 to the X12 engine around 2020. They are largely used on routes to and from New York City, as well as long-distance routes in southern New Jersey. My model depicts bus 20052, a 2020 model year unit assigned to Wayne Garage. I began working on this model in August 2022, starting with the Stud.io model. I wanted to build this model in traditional NJT colors, which includes silver stainless steel panels on the sides and a black upper rear section. I wanted to build at the same scale as my New Flyer XD60 model (roughly 1:20), and thankfully the rims for the 62.4x20 tires are available in metallic silver to match the silversides. I also ensured the seating layout is identical to the real-life NJT MCI D4500CT, with 57 seats on non-lavatory units (30 units equipped with lavatories from the 2018 and 2019 model years have two fewer seats). The model uses the Control+ system for electronics - the drive axle is driven by a Control+ XL motor and steering is controlled by a Control+ Large motor. Initially I planned to use a Control+ Large motor for the bi-parting passenger door as well, located in the roof support frame, but the two door panels would not open evenly since the drive from the motor is first transferred to only one of the panels. I eventually placed the entire door mechanism under the passenger entry in the front, and a WeDo 2.0 Medium motor is used to power the doors as its shorter length allows it to easily fit in the limited space. My initial design also sought to include a functioning wheelchair lift with its functions (extending/retracting, elevating/lowering and wheelchair lift door) along with the passenger door controlled by a 4-output distribution gearbox. Work on the physical model did not begin until November 2022, at which point I already had the chassis and axles largely modeled in Stud.io. After building the wheelchair lift mechanism I found it to be ineffective in practice - because the lift slides in and out from the side of the model and needs to elevate and lower in a limited space, the mechanism eventually had so much friction that the motor powering it stalls when the extension and elevation functions are selected and the elevation mechanism has so much backlash that the lift would not lower even after rotating the input of the mechanism until it eventually drops all of a sudden. I eventually decided to abandon the wheelchair lift mechanism (the 4-output distribution gearbox was saved for my Mack Granite Boom Truck model which also helped test the suspension design for this MOC). In the end the lower part of the model where the luggage compartments are normally located only contain the Control+ hub and Technic frames for rigidity. Because the underside is largely covered with Technic panels, I used the newer Control+ hub with screws as there is no need to leave open space around the hub for access to the battery door latches. In the end removing the wheelchair lift mechanism was a good call, as even without it the model is very heavy at over 6100 pieces. Similar to my previous bus models, this model features a System finish with Technic inners. Much of the chassis between the front and rear axles is quite empty, with the only electronic components being the Control+ hub and the drive motor (the steering motor is integrated in the suspended front axle). There is a Technic roof support frame as well, but because all electronic components are placed in the chassis, the frame is kept simple (consisting of mostly 11x15 Technic frames) and the lack of exposed wires in the interior is another advantage. However, there is a vertical axle in the interior allowing for pressing the power button of the Control+ hub from the roof. Reinforcing the roof support frame was a challenge though, as the real-life bus has the left and right side seats slightly offset from each other. This meant a vertical support beam on the left side may not work on the right side, as the beams must sit directly behind the window pillars to remain unobtrusive. Another challenge was the rear of the chassis, as it had to be kept largely open with no transverse reinforcements for the removable Cummins engine model connected to the drivetrain. The sections of the chassis directly above the front and rear axles also had to be kept open yet reinforced for the suspension - I also had to change the front suspension to two shock absorbers per wheel as the model got heavier which required rebuilding a significant portion of the front chassis section. The front of the chassis would still experience some bending even with the roof frame in place, but after the bodywork was added the issue was largely mitigated. As for the passenger seats, my initial design had them as System builds finished with dark blue tiles and slopes (the real-life NJT MCI D4500CT has two-tone blue vinyl covered seats), but because ordering so many dark blue pieces for an interior feature would be expensive yet still not capturing the two-tone blue finish, I decided to use Technic panels for the seats (part 24116 with 2L liftarms to slightly increase their height). While they are slightly less realistic, they offered a much more rigid connection to the Technic inner floor and likely helped reduce the weight of the model. The bodywork consists of a largely seamless white finish made using System pieces. Like my MTA New Flyer XD40 model, I made sure all connections to the Technic core are made using white Technic axle pieces into Technic bricks with axle holes to prevent exposed Technic pins. The roof however is still made using Technic panels, and a section of the roof also contains the power "button" which pushes the vertical axle for the hub power button mechanism. One of my goals when I started working on this model is for the silversides to actually be silver, not light bluish gray. Because the LEGO metallic silver palette is limited, I had to make sure all the parts I need exist and can be acquired in the numbers I need. LEGO's Pick A Brick came in handy here, as I was able to order over 70 2x4 tiles in metallic silver and several other metallic silver tiles, and acquiring the metallic silver pieces alone cost over $80. The passenger door was more of a challenge as the door panels are made using Technic pieces and some pieces I need (such as a 1x4 thin liftarm) do not exist in metallic silver, so unfortunately there is still some light bluish gray in the doors. The New Jersey Transit livery is done using custom stickers, mostly on transparent glossy sticker paper but also some on white sticker paper for those that do not sit on a white section (e.g. the silverside panels). I also included a mechanism for easily removing the front destination sign which allows for changing the destination displayed on the sign. The side destination sign is connected using only two pins which also allows for easy removal. Finally, because the run sign (the number display at the lower right hand corner of the front windshield) is only attached using two half pins, the number displayed on the run sign can also be easily changed. Overall, I'm satisfied with how my third motorized bus model turned out. At over 6100 pieces, it has nearly 1000 more pieces than my New Flyer XD60 model from two years ago. The System finish for the bodywork allows for a largely seamless look and the metallic silver for the stainless steel panels really make the silversides stand out. However, the heavy weight of the model also means the drive speed is quite slow, and I also noticed the front wheels would struggle to stay upright after driving it for a while. This could be mitigated by adding a second drive motor and Technic wheel hubs for future bus models of this size. Despite these issues, the other functions worked flawlessly, and I'm especially satisfied with how the bi-parting door mechanism came together. It's been a very rewarding two years working on this model, and I still have many more motorized bus models planned for the future. Instructions will be published on Rebrickable once they're finished. Video: Photos:
  6. The instructions are now published on Rebrickable: https://rebrickable.com/mocs/MOC-185091/JLiu15/race-buggy/#details
  7. An off-road race buggy model powered by BuWizz. Features a drivetrain containing 2 RC buggy motors and a 4-cylinder piston engine, full independent suspension, and working headlights and taillights. Functions: Drive Steering 4-cylinder engine Full independent suspension Working headlights and taillights Instructions available on Rebrickable: https://rebrickable.com/mocs/MOC-185091/JLiu15/race-buggy/#details All my MOCs containing RC buggy motors so far have had the motors connected straight to the wheels or tracks (either directly without gearing or via a gear reduction). However, I have always been wanting to build something with a proper drivetrain since acquiring those motors. This would make it much easier to incorporate e.g. a differential and independent suspension on the driven axle. Because the 42160 Audi set offered brand new non-planetary hubs that use heavy-duty CV joints, they made for a good starting point for this MOC. Initially I was inspired by the 42160 set's BuWizz motorization which placed two BuWizz motors with their outer outputs connected to form the main driveshaft. However, because I was worried the vertical orientation of the motors in that design would add unnecessary height to the model, I still went with placing the motors horizontally in a transverse position with the inner outputs forming the driveshaft. Although the inner outputs have higher speed and lower torque than the outer ones, connecting the two motors via their outer outputs would result in an unnecessarily wide chassis. Even in the final setup, the motors still protrude from the sides of the body slightly, which interferes with the finished bodywork. Another challenge with the motors' placement is reinforcing the chassis, as their transverse placement makes it difficult to reinforce the chassis longitudinally where the motors sit. While there is longitudinal reinforcement above the motors, the front chassis and rear axle sections are only connected to the bottom of the motors by the friction of pins. I was initially concerned that this would be a weak spot in the chassis, but once the bodywork was installed it was not an issue. The compact design of the rear axle also allowed me to easily include an inline 4-cylinder piston engine (in clear engine blocks this time to allow for better visibility of the pistons), which is another advantage of having a proper drivetrain vs connecting the motors straight to the wheels. The rear suspension design is similar to that of the 42160 set, with the hubs' steerability restricted by liftarms on both sides. The front suspension has the same geometry as the rear suspension, but because the front axle is not driven, there was no need for specialized hubs, I decided to use the older steerable hubs on the front axle as the integrated towballs for the steering links proved to be a more robust setup. The full independent suspension had decent travel and was quite soft, which is good for a model like this. I also added three sets of Power Functions LEDs to the model (one for the headlights and two for the taillights), although it is mostly for show as I kept them off during driving to allow the RC buggy motors to have enough power. Managing the wires was also a challenge for a model this size, as there are seven electronic components (including the BuWizz) despite having around just over 800 pieces. Finally, as for the bodywork, I went with dark blue as I have a good amount of dark blue Technic pieces from the 42083 Bugatti and 42154 Ford GT sets. Although there are some details done using System pieces, I kept them to a minimum to ensure the robustness of the model. Performance-wise, this model exceeded my expectations. I was initially concerned that the gears in the drivetrain and piston engine would add some friction, but that was not an issue. I filmed the video at the skate park like my Red Beryl T (my previous MOC), and honestly it performed even better. It had enough momentum to go up the slopes at the skate park much more than my Red Beryl T, and I think the lighter weight of this model helped with that. The wheel diameter is also bigger (I used the tires from the 42160 set), and the final gear reduction is slightly less (7:3 vs 3:1). It was quite fun to drive it around, although I did have issues with the BuWizz cutting power (especially during heavy acceleration or on Fast/Ludicrous modes) and sometimes I ended up driving it too far up a slope where it started getting stuck. Despite the issues, it was still a very agile vehicle and had plenty of speed for some fun driving. Overall, despite being a simple sub-1000 pieces build, this model ended up being a fun one packed with functions. The RC buggy motors provided plenty of speed and the drivetrain handled that speed well. The 4-cylinder engine and PF LED lighting, although mostly for show, allowed me to squeeze in as much functionality as I can in a small build. I still see potential to further develop things, such as taking the drivetrain setup and extending it to an AWD design. Video: Photos:
  8. Thanks! I have more bus MOCs planned for the future
  9. Thanks! It's a great color and I love that it's used more in Technic now (e.g. the 42154 set)
  10. Thanks! I also felt it looked better IRL than in Stud.io.
  11. UPDATE 5/16/24 The model is essentially finished with just over 800 pieces. Thanks everyone for the input on the rims - initially I decided to switch to gray rims but in the end went back to the original black rims. I'm still debating on adding PF LEDs to the model (for front and rear lights) - power shouldn't be an issue as I can keep them off when requiring full power for the RC motors, but not sure how manageable the extra wiring will be. After putting on the wheels, the suspension turned out very well with a large amount of travel and is not too soft or hard. There are a number of modifications from my original Stud.io model, most notably the rear wing which has been changed to a simpler and more robust design. I've also changed the front hubs to the older design with integrated towballs for a more robust design. Photos:
  12. UPDATE 5/16/24 After nearly two years of development, the build is finally finished. It is my largest MOC to date with 6117 pieces, surpassing my New Flyer XD60 from two years ago by nearly 1000 pieces. The only thing left is to make custom stickers to decorate it in the NJ Transit livery. While the real-life bus spans seven model years (with deliveries taking place from 2016 to 2022), my model is of a bus from the 2020 model year. The build actually sat at roughly 98% complete for several months. By late January the build was essentially complete. However, I later noticed that I had forgotten about the vents on the roof towards the rear. Because they are only visible from the roof, it was an easily missed detail that I didn't notice until I saw a photo of the real bus taken with the roof visible. The upper rear section was modified to accommodate the roof vents, and while I had the design finalized in Stud.io for quite some time, I had put off rebuilding it on the physical build since I was busy (it required taking a good amount of the rear apart to rework the inner structure). I've finally updated that part, and now the build is finished. Photos:
  13. I've also been debating on alternate rim colors - besides black rims, I've considered gray and gold rims. Which option (black, gray, gold) do you guys think is best? Thanks! Black rims: Gray rims: Gold rims:
  14. Thanks! Thanks for the warning - guess I'll have to be careful lol. Especially with these being the clear engine blocks.
  15. I have been busy the past few months, so I have not had much time to build despite much larger MOCs sitting at 95% completion. It was difficult to get things rolling again as I had not planned any MOCs for a long time. With Brickworld Chicago just over a month away, there wasn't much time to plan anything major especially with a 6000-piece MOC nearly complete. There's a number of things I've been wanting to try for the past few months, and one of them is the new elements from the 42160 Audi set. The new hubs from the set are perfect for double wishbone independent suspensions requiring heavy duty CV joints, and the tires are a great fit for any off-road vehicle. Since acquiring two RC buggy motors I've only configured them to drive a single wheel/track each and never with a proper drivetrain, so for this MOC I decided to do that - the drivetrain consists of two RC motors placed with their inner outputs connected, and drive is connected to a differential before going to the rear wheels. I've also thought of doing a 4WD setup, but figured it would overcomplicate a vehicle designed primarily for speed. The use of a proper drivetrain also means I can connect a piston engine to it - an inline 4-cylinder fits perfectly into the space in the rear, and because I went with clear engine blocks the pistons' movement is visible from all angles. When I tested it, the pistons move very fast as there is no gear reduction from the RC motors' output. I decided to go with a dark blue color scheme for this model as it's a color not commonly used in Technic and I have a good amount of dark blue pieces from the 42083 and 42154 sets. I've also considered red, but since I have just made a trophy truck MOC in red last summer, I figured it was too soon to go with red again. I also wanted to keep the design here unique and not look like a copy of my Azure Racer XL MOC from a few years back, but there are already plenty of internal differences as this MOC has a double wishbone rear axle and a piston engine in the rear. I'm looking forward to how this MOC performs - it has a piston engine connected to the drivetrain like my original Azure Racer but also has full independent suspension. It'll be interesting to see for sure. If you have any suggestions for me, please let me know. Photos: