JLiu15

UPDATE 8/9/23 I've finished designing the model in Stud.io. Below is a rendering of the model. I decided to go with only one spare tire instead of two to reduce unnecessary weight. Piece count according to Stud.io is 1333.

UPDATE 8/7/23 A little more progress on the model, with the roof and A-pillars installed. The A-pillars were trickier as they sit at multiple angles, so I installed them on the physical model before modeling them in Stud.io. The roof section was also modified slightly from my initial design in Stud.io to accommodate for the A-pillars. As of right now the front suspension sits lower than the rear suspension. This should change once the rear of the model is complete, as including one or two spare tires in the back should help balance the front and rear suspension heights. Photos:

UPDATE 8/4/23 I redesigned the body of the model and completely rebuilt everything from scratch. This is because I had to use pieces from this model to build my MTA New Flyer XD40 model. The design is now simpler than before, and I was able to add PF LEDs for the headlights as well. I have most of the lower parts of the body built, with the design mainly consisting of Technic panels. There will also be some System pieces behind the cab, which I have not put in place yet. I still have to design the rear of the body and will likely include two spare wheels in the back. The suspension is soft enough with the body installed that the shock absorbers are partially compressed while the model is on the ground, which should be good for the model's performance. Photos:

The instructions are now published on Rebrickable: https://rebrickable.com/mocs/MOC-153565/JLiu15/2015-new-flyer-xd40-mta-bus/#details

Thanks! Thanks for the correction!

Thanks! Initially I thought I had to limit the turning radius to prevent the wheels from colliding with the chassis, but I removed some pieces and the Servo motor is able to turn a full 90 degrees.

Thank you!

Model of a New Flyer XD40 transit bus in MTA livery. The model has roughly 3800 pieces. Features motorized drive, steering with working steering wheel, passenger doors, and a removable Cummins engine model with moving pistons. Functions/features: Drive Steering with working steering wheel Remotely controlled doors Removable Cummins engine model with moving pistons Instructions available on Rebrickable: https://rebrickable.com/mocs/MOC-153565/JLiu15/2015-new-flyer-xd40-mta-bus/#details Because my NJ Transit New Flyer XD60 model was a huge success, I decided to reuse my design and make another Xcelsior model - this time a XD40 in MTA colors. Unlike my NJT XD60 model which has the livery done entirely using stickers, the blue stripe livery MTA used prior to 2016 is easy to design with blue LEGO pieces. As a result, the model is recognizable as a MTA bus even without stickers, which is why I specifically included "MTA Bus" in the name. The model is not simply my XD60 model cut shorter. The chassis is redesigned from scratch. The front and rear axles are placed at a half-stud offset to allow for smaller wheel arches. The XL motor for drive is placed in front of the rear axle instead of behind it to allow space for the Cummins engine model. The battery is placed much higher and is accessible by removing the upper rear body panel. I added a switch on the roof to allow the battery to be turned on without removing the body panel, so it only needs to be removed for charging. There are also no supports in the chassis for the rear door as the rear door on MTA Xcelsiors open outwards, and the front of the chassis is redesigned to accommodate both the mini linear actuator for the front door and the connection from the steering wheel to the Servo motor for a working steering wheel. Lastly, the chassis is also designed to specifically accommodate for MTA's seating layout, most notably with only a single seat per row on one side in the low floor section. Like my XD60 model, there is also a roof frame that holds both motors for the doors as well as the rear door mechanism (which uses the same general principle as the inward-opening front door despite opening outwards). The roof frame is attached to the chassis using beams, making for a robust "skeleton" that the body is built around. The bodywork has also been redesigned in several places. The wheel arches are now smaller due to the half stud offset of the front and rear axles, although I had to use inverted slope pieces instead of arch pieces to allow the blue stripe to be built entirely in LEGO. This means the wheel arches are not perfectly curved here, but I found it to be a fair compromise for making the entire blue stripe in LEGO. The front lower body panel is one stud higher here compared to my XD60 model, although it kind of makes it look like the front of a MTA Orion VII NG (MTA Xcelsiors in the blue stripe livery have the bottom edge of the front windshield curve downward slightly, and such a curve would be very difficult to model in LEGO at this scale. The rear body panels use a simpler and more robust design, the front roofline curves are angled slightly outward (the space between them was increased by 2 studs), and the side body panels are attached to the chassis/roof frame using white 1x1 Technic bricks with axle hole and part 27940 in white. This allows for a seamless body without pins showing; part 27940 in white was not yet available while my XD60 model was being built. The roof is primarily built using 6x6 tiles this time instead of 5x11 Technic panels - because MTA's 2015 XD40s do not feature a full roofline, the transition from the side body panels to the roof is much more noticeable here which is why I went with the tiles. The model's functions all worked well. The single XL motor was more than enough to power the model, especially considering this model is lighter than my XD60 model. Although the moving pistons on the Cummins engine model are not easily visible (there's one piston visible under the last row of seats), I am happy that I was able to add some additional functionality to this model. And because the pistons are made using half bushes, the engine makes a nice sound while the drive motor is running. While designing my XD60 model I thought there was too little space in the front to incorporate a working steering wheel without compromising the rigidity of the chassis, but I was able to connect the steering wheel to the Servo motor just fine here. There is less reinforcement immediately in front of the front wheels so they don't collide with anything when steering, but the side body panels keep everything robust. I did not test the rear door mechanism before installing it on the model so I was concerned how well it will perform, but it is usually able to open the rear door fully with each door panel rotating 90 degrees. Sometimes the mechanism gets stuck while opening the door, but reinforcing the pieces a little usually solves the problem. While at first glance this MOC looks like my XD60 model shortened and without an articulation joint, it was really a new MOC from scratch. The chassis is completely redesigned and has little resemblance to the chassis of my XD60 model even without accounting for the lack of the articulation joint and a third axle. The bodywork was also improved in several places. All of the functions performed as expected, and the finished model is easily recognizable as a MTA XD40 even without stickers. Speaking of which, I decided to make my model bus 7225 operating out of Grand Avenue Depot in Brooklyn signed for route B62. Overall I am very satisfied with how my second bus MOC turned out, and I plan to continue making bus MOCs in the future, with one already in progress. Video: Photos: Brickworld Chicago Photos:

Not sure if this is the right place to post this or if it's been answered already, but does anyone know why LEGO discontinued the Control+ XL Motor? https://www.lego.com/en-us/product/technic-xl-motor-88014 I remember a video showing its speed/torque were pretty similar to the Control+ L motor, so I guess LEGO didn't see a reason for keeping it around considering the L motor is smaller. It also hasn't been used in a set since 2020. This also makes me wonder - could there be an overhaul of the Control+ system on the horizon? A redesigned XL motor and additional sizes of motors?

The instructions are now published on Rebrickable: https://rebrickable.com/mocs/MOC-150955/JLiu15/mack-granite-boom-truck/#details

Brickworld Chicago Photos:

Thank you!

Model of a Mack Granite truck equipped with a boom and flatbed. Features drive, steering, full suspension, motorized boom elevation, extension, and rotation, winch, and extending/lowering outriggers. Functions/features: Drive Steering Full suspension Boom elevation Boom extension Boom rotation Winch Outriggers Instructions available on Rebrickable: https://rebrickable.com/mocs/MOC-150955/JLiu15/mack-granite-boom-truck/#details After the 4-output distribution gearbox on my MCI D4500CT Commuter Coach model proved to be ineffective, I didn't want to simply abandon the gearbox design. I decided that I was going to tweak the gearbox a little to be used in a new MOC. I had wanted to use the same suspension setup for my MCI D4500CT model as a test bed for the suspension design, so I settled on incorporating the gearbox into a truck model. A boom truck like this is a MOC I had wanted to make for quite some time, as I see plenty of them in the US but not that many MOCs of them. Because the turntable for the boom is placed higher up, it leaves more room to route gears/axles from the gearbox to the 4 functions it controls. Because the gearbox sits in the heart of the chassis between the outriggers and rear axles, the chassis is built very densely. The gearbox makes use of two Control+ L motors: one for shifting and one for driving the output functions. The drive motor (a Control+ XL motor) sits directly behind the gearbox, and drive is transferred to the rear axles via an extendable CV joint. The drivetrain is geared down after the CV joint to reduce the amount of torque applied to it. Lastly, there is another Control+ L motor for steering which is built into the front axle. I designed the suspension (a simple live axle for all 3 axles) entirely in Stud.io before building it physically, so I had no idea how it would perform upon building it. However, the entire setup worked flawlessly, and there are no issues with drive transmission into the suspended rear axles. My initial plan for this MOC was to just build it as a generic US-style truck, but upon finishing the cab someone said it resembled a Mack Granite, so I modified the cab to actually make it based on the Mack Granite with the Mack Bulldog emblem from the 42078 Mack Anthem set in the front. A number of metallic silver elements are used in the front, although due to the relatively low number of pieces available in that color there is still plenty of gray in the front (such as the bumper). The Control+ hub is placed in the back of the cab and is removable for battery replacement by removing the roof, as the hub and roof are attached to each other. This means the sides of the cab must be sturdy to compensate for the relatively loosely attached roof, so the doors do not open on this model. I decided to build the cab in dark blue, a color I have not used much before, as I now have a sizeable collection of dark blue pieces from the 42083 and 42154 sets. I built the boom in yellow to contrast with the dark blue cab. The boom is built around 3x19 frames covered with tiles. Their abundance of pin holes makes them a good candidate for crane booms. It was difficult routing the two motorized functions through the turntable and into the boom, as two separate axle functions must pass through a small space. Because only two axle functions can be routed through a turntable, I had to make the winch manually operated with a ratchet mechanism. I was initially concerned about the weight of the boom, and while the boom does tend to lean forward during the elevation process, everything remains intact even at maximum elevation and extension and the range of the boom is quite impressive. There are no stoppers for the boom rotation, so the boom can theoretically rotate infinitely as there are no wires going through the turntable. The outriggers, however, were a weak point for the model as they are quite flimsy and are unable to lift the truck off the ground without substantial bending, so I limited the outriggers' legs extension to where they are able to make contact with the ground. Additionally, I should have geared down the mechanism substantially more, but a modification would require essentially rebuilding the chassis from scratch. As a result, I set the gearbox motor responsible for driving the gearbox functions slightly below maximum speed. I had wanted to be able to control the gearbox functions with a single touch (e.g. pressing one button shifts the gearbox then drives it in a given direction) but was not able to figure it out so I went with a much more straightforward (albeit more difficult to use) controller setup. A single slider is used to drive the gearbox functions, and three buttons are used to shift the gearbox (up 90 degrees, down 90 degrees, and return to one endpoint). I have to keep in mind the position of the gearbox while controlling the model, but the setup overall worked well. Overall, this was a MOC that had plenty of mechanical complexity, but certain functions could've been designed better. While all of the functions work as intended, the boom leans forward quite a bit when the boom elevates and the outriggers cannot lift the truck off the ground. The front axle could've also been reinforced better, as during the steering calibration process the steering pinion gear often skips a tooth. Despite the drawbacks of this MOC, it still largely met my expectations as the drivetrain and suspension worked flawlessly and the dark blue/yellow color scheme worked well. Video: Photos:

UPDATE 6/12/23 The build is complete. It just needs custom stickers for the MTA livery now. Final piece count is just under 3800. Photos:

UPDATE 6/8/23 The left side body panel is in place. The model is starting to look like the real MTA XD40. Thanks to the use of 1x1 bricks with axle hole and white connector pieces, the bodywork is seamless with no pins showing. Photos:

UPDATE 6/7/23 The doors, rear body panels, and destination sign are in place, as well as the flip-flop beams with half pins on the roof frame which will be used for attaching the tiles on the roof. The front and rear door mechanisms are different as the rear door opens outwards. However, the principle is similar. I was initially concerned that there would be too much play in the system for the rear door mechanism to work properly, but it ended up working pretty much flawlessly. The rear upper panel is removable for accessing the battery. I was initially intending to only have the central part removable, but there would be no place to grip it to open it once the body is complete. I ended up incorporating a lever that hits the button on the 8878 battery that will stick out from the roof, so the panel only needs to be removed for recharging. Let me know if you have any suggestions for me! Photos:

UPDATE 6/5/23 The chassis is now complete along with the roof frame and front body panel. Like my XD60 articulated bus model, the motors for the doors are in the roof frame. However, the rear door mechanism is different as on the real MTA XD40s the rear door opens outwards as on the real bus they are opened by touching a yellow tape. As shown in the previous update, one upgrade from my XD60 model is the removable Cummins engine with moving pistons. Another upgrade is the working steering wheel, which I was able to route from the Servo motor under the front door's linear actuator. Let me know if you have any suggestions for me! Photos:

UPDATE 5/20/23 I've finished the Stud.io model and made some renderings. Overall it was a pretty straightforward process as I already have my previous XD60 model to base it on. The chassis, however, is completely different from my XD60 model. I was even able to fit a Cummins engine model in there which is removable, and while it's pretty crude, the open design of the chassis (as opposed to covering everything up) means that the pistons will be somewhat visible without needing to remove the engine. Piece count according to Stud.io is 3676. I'll order the parts I need and begin the building process. Renderings: Battery access: Engine close-up:

Following the success of my New Flyer XD60 model, I decided to take the existing design and remake it into an XD40 in Metropolitan Transportation Authority (MTA) livery. I am doing the 2015 model since newer ones have the new blue livery which will be much harder to build in LEGO due to the availability of dark blue pieces. The design uses my previous XD60 model as a base, but this model is more than simply my XD60 model cut down by 20 scaled feet. The chassis is redesigned from scratch, with the front and rear axles at a half-stud offset to allow for smaller and thus more realistically sized wheel arches. The body panels are also attached to the chassis using white Technic bricks with axle hole connected to a white Technic piece with axle, allowing for a seamless finish with no visible pins. A number of details have been polished up since my XD60 model, but perhaps the biggest difference is that the livery won't be sticker-dependent on this model. The simple blue stripe livery means I can easily model it with LEGO pieces, and stickers will only be used for the bus numbers/lettering. I've only modeled it in Stud.io so far, but I largely know what to expect since my XD60 model so the actually building process should be pretty straightforward once the model is finished in Stud.io. Photos:

Thanks! I will be publishing instructions for it once that's all done. Yes, although it does make the chassis bend a little despite plenty of reinforcement. Unfortunately the outriggers are the weak point of this MOC - they are quite flimsy when extended and extend/retract very fast (I should've geared it down and used a worm gear or something but changing it would mean taking the entire chassis apart at this point). The outriggers can touch the ground but cannot lift the truck off the ground.

UPDATE 5/11/23 I've built the chassis of the model with all mechanisms and electronics in place. The front axle has double wishbone independent suspension with ~10 degrees of positive caster. The rear axle is a solid axle; the suspension geometry is the same as on my Azure Racer XL MOC but is extended to increase suspension travel and decrease hardness. The BuWizz unit is placed low in the chassis right before the rear axle, which should lower the center of gravity. The suspension is pretty soft, which is good since as far as I know, trophy trucks usually feature soft suspension with long travel. Photos:

That was the very mistake from the first time I built this - the Claas tractor tires proved simply to be too big. The wheels and wheel arches are the same as the 42126 Ford Raptor.

UPDATE 5/9/23 I decided to revive this MOC but with a radically different approach. A lot has changed with LEGO Technic in the past two years, and one of the most significant is the addition of plenty of new Technic panels. Instead of having a drivetrain with a gearbox and differential, the RC motors will be connected in a similar manner as my Azure Racer XL MOC. In fact, the suspension maintains the same geometry - the only difference is that the left and right rear wheels are not independently suspended and are connected in a solid axle instead. The front axle still has positive caster (about 10 degrees). It will also be built at a smaller scale than the original design from two years ago, using the tires from the 42124/42126 sets. Although I only have the Stud.io model here, I did build the rear axle and suspension. It's not pictured as I have to make some changes to it. Current piece count: 1166 Photos:

Thanks! The drivetrain has plenty of speed and torque even for such a heavy 3500+ pieces model. Thanks! What size were my images? Not sure what size they are as I took them with my iPhone and uploaded them straight to Imgur. I'll be mindful of this in the future!

Thanks! Not sure if I'll be going yet, but if I go to Brickworld Chicago this summer I plan to bring this MOC!