JLiu15

UPDATE 5/9/23 The model is 99.9% complete. The only things missing now are the Mack bulldog hood ornament from the 42078 set and the winch. I tested all the functions and they work fine. I was initially concerned about the weight of the boom, and while raising the boom does cause it to lean slightly at the turntable, the model maintains its structural integrity regardless of the height the boom is raised to. In fact, even with the boom fully raised and extended, everything remains structurally sound. While there are certainly parts I think can be improved, I'm overall satisfied with how this MOC turned out. The final piece count will be around 3529. Photos:

I don't have a gaming controller. They're pretty expensive and I'd rather not spend the money on one right now. Also the Powered Up app does allow PU motors to make 90-degree rotations (or any degree). The issue I'm having right now is properly calibrating the motor to rotate to one of its endpoints. Steering servos check for the two endpoints and then rotate to the center position - the difference is that I need it to go to either of the two end positions rather than the center position. The 42131 and 42114 sets both do this with the gearbox motor. Again @kbalage made such a control profile in his review of the 42131 set where the press of a button shifts the gearbox into one of its end positions, and that's what I'm trying to achieve here. Right now I have it set to rotate -270 degrees to move it to an end position, but it just ends up stalling the gearbox motor for a while when it cannot make a full -270 degree rotation (e.g. if the gearbox position was at 0, 90, or 180 degrees earlier).

UPDATE 5/1/23 Finished upgrading the truck to a Mack Granite. The original design was already pretty close to the Mack Granite, so all I had to do was modify some areas and order a few new parts. Since the original design was already so close to a real truck I didn't want the opportunity to go to waste. The only part I'm not really happy with is the front fenders - they are much more rounded on the real Mack Granite. However, based on the photos I saw the fenders tended to vary between generations. I wish LEGO had a greater variety of curved System pieces. The model is still missing the most important piece that will distinctly make it a Mack truck - the Mack bulldog emblem. I ordered the Mack bulldog piece from the 42078 Mack Anthem set, but it is part of a different order as they are pretty hard to come by now that the set is retired. For some reason this piece is not available in Stud.io. Photos:

Someone said that the model looked like a Mack Granite, and it is indeed pretty close so I made some modifications to the cab to actually make it a Mack Granite. It's not perfect, but it's much closer to the Mack Granite than the original design.

UPDATE 4/28/23 I've completed everything except for the boom. The rear axles, rear bed, and outriggers are all in place. While attaching the rear axles the chassis above it was bending severely. I had to go back and add reinforcement to that section. My initial chassis design in Stud.io only had one stud thickness above the rear axles to ensure the rear suspension isn't obstructed. I've increased the thickness of that section, and while there's still a negligible amount of bending, it is not too noticeable especially with the rear bed in place. I've also tested all motorized functions and made a simple control profile that can shift the gearbox 90 degrees in both directions. All functions seem to work well and the drivetrain has a good balance of speed and torque. The outriggers extend very fast though, and in retrospect I should've used a worm gear mechanism or something but incorporating it now would mean completely stripping the chassis and rebuilding as the gearbox is buried in the heart of the model. I will probably just run the motor at 50% power for this function. Same for the boom rotation - it's not that fast but still could be slowed down slightly to look more realistic. It'll be interesting to see how all motorized functions perform once the boom is installed. Current piece count: 3543 Photos:

Hey guys, not sure if there's already a thread dedicated to the Powered Up app so mods feel free to move this if there's a better place for it. I'm building a remote controlled MOC using Control+ that has a 4-output distribution gearbox controlled by a rotary selector. It is basically the same setup as in the 42131 CAT D11 set. Right now, I have the controller program first rotate the gearbox motor to one of its endpoints at the start of the program, and two buttons that allow the gearbox motor to be shifted upward or downward by 90 degrees. I believe @kbalage used a similar setup to test the 42131 in his review video as the official control profile wasn't released yet at the time. However, it would be much more convenient if by pressing and holding a single button the gearbox shifts into its correct position and the motor driving the function runs until the button is released, and the gearbox moves back into its starting position at one of its endpoints. This is the way it's done in the official control profiles for sets like 42131, 42114, etc. I've tried a variety of solutions but had no luck. Does anyone know how to create such a setup, preferably with the corresponding code? Thanks!

UPDATE 4/20/22 I've added the outrigger legs and the boom support to the Stud.io model. Now it should have everything that the finished model will have. Current piece count is 3436. I've made another rendering of the Stud.io model - the finished model will more or less look like this:

UPDATE 4/19/23 I have a preliminary design for the boom modeled in Stud.io. The boom is made using the new 3x19 frames with tiles on the outside to hide the pin holes. Not sure if the boom will be too heavy, but the number of pin holes on the 3x19 frames definitely makes them much better suited for the boom than Technic panels. I was initially planning to include a second gearbox above the turntable to allow the winch to be motorized, but space was limited so I ultimately went with a manual winch. I still need to add the support frame for the boom in the back and the outrigger legs to the Stud.io model, but right now the Stud.io model is more or less what the final model will look like. Current piece count: 3356 Photos:

Thanks! Obviously the real model is still unfinished but I’m looking forward to the end result once I get the pieces I need.

UPDATE 4/17/23 I've finished the boom base including all mechanisms within it and have begun working on the cab. I'm liking this dark blue and yellow scheme and it makes for a nice contrast. Unfortunately I realized I'm still missing some parts for the cab (mostly dark blue System pieces) so I'm currently waiting for a BrickLink order to come in. I'll also have to find a few more metallic silver grille pieces as the seller I purchased from didn't have the amount I needed. I've also cut down the chassis by about 5 studs in the rear. The previous design looked way too long, and it would also mean making a longer boom. I've made the drivetrain more efficient by placing the CV joints closer to the drive motor instead of routing them behind the rear axles. That design was simply carried over from my MCI D4500CT model as that one will also have a fake engine behind the rear wheels. Since there's no fake engine in this model, I was able to reroute the drivetrain and make it more efficient. I will probably start building the rear of the chassis once the cab is complete. Let me know if you have any suggestions for me! Photos:

UPDATE 4/9/23 A little more progress on the physical build. The front portion of the chassis is complete, with an opening for the front axle which will feature live axle suspension. The two liftarms protruding upwards where the cab will be located is to secure the Control+ hub which can be removed along with the roof for battery replacement. The chassis directly above where the front axle will sit is very rigid - it was a lot more reinforced than I thought it would be. I haven't built the front axle yet, but I'm pretty confident at this point that there won't be any rigidity issues when the suspension compresses. Let me know if you have any suggestions for me! Photos:

UPDATE 4/8/23 The physical build is underway. I've got the heart of the chassis built, which contains most of the mechanisms. Those of you who have followed my progress on my MCI D4500CT model might see some resemblance, with the biggest difference being the frame supports for the boom above the gearbox. I was concerned that the boom base isn't reinforced as much since the frames sit slightly above the chassis to allow the worm gear mechanism for the boom rotation to sit below the frames, but the structure turned out to be pretty robust. The outriggers are also in place. I was concerned that the outriggers would have too much sideways movement when extended, but they also turned out alright. They do move upwards slightly when extended and under load, but my plan is to just have the outriggers stabilize the truck rather than lift it off the ground. The actual legs of the outriggers (which I haven't modeled in Stud.io yet as I want to wait for the wheels to be put on first) will probably just be a locking linkage mechanism (like on the 8258 Crane Truck). Let me know if you have any suggestions for me! Photos:

UPDATE 3/27/23 I've modeled the cab of the truck; I decided to do it in dark blue as I feel it complements the yellow boom well. The side fuel tanks are also in place. Below is a rendering of the Stud.io model so far. Current piece count is 2801. The only thing I have to model now is the boom, which is its own separate module so I will probably begin building the physical model soon. The roof of the cab is connected to the Control+ hub, and can be removed along with it to change batteries. Because the roof and hub are removable, the doors do not open in order to give the cab extra support. Honestly, the model is turning out much better than my expectations. While there's certainly room for improvement with the cab design, I just love the way it turned out. I like the dark blue too, and since I got the 42154 Ford GT set recently, that set will provide a lot of the dark blue pieces I'll need.

UPDATE 3/25/23 I got the front axle attached to the Stud.io model. Right now the model looks a little weird, but it should be better once the cab is modeled. Current piece count is 2167 - I expect the finished model to have 2000-3000 pieces. Photos:

UPDATE 3/23/23 I have not touched the model since my previous update, but in the meantime I completely reworked the Stud.io model. The front and rear ends of the chassis remain largely the same, but the space in between the front and rear axles was essentially reworked from scratch. Because the wheelchair lift mechanism proved to be impractical, both the gearbox and the wheelchair lift mechanism were stripped. The drive motor and Control+ hub remains in the same locations. I was thinking of adding a second Control+ XL motor for drive since there is an extra port on the hub available without the gearbox, but such a design proved to be very wide. I thought of moving the hub towards the center of the chassis, but it looked awkward sitting in the middle of the chassis with nothing else surrounding it and the hub in the front could act as a counterweight to balance out the engine model. The new chassis design is much more symmetric since it no longer has to accommodate for the gearbox and wheelchair lift mechanism, which made the attachment points for the passenger seats easier to install. The following screenshots are of the Stud.io model with seats, side panels and wheels hidden. When the hidden elements are shown, the appearance is not much different from the previous design. However, it did allow for a simpler design of the side "stainless steel" panels as previously the plates which the silver tiles sit on had gaps to allow for 12T gears to rotate for the wheelchair lift mechanism. The right side panel also had a gap for the wheelchair lift door, which has now been eliminated. Screenshots of the full Stud.io model are shown below.

Thanks! Not sure how I will design the cab yet, but my plan is for it to be in the style of an American long-nose truck.

Looks like I had that option selected. I turned it off and those pieces were showing again!

Recently as I've been using Stud.io, I've found that many pieces (mainly Technic) I often use have become unsearchable. They still show up if I already have them in my model and I click on them, but searching for the part or even part number turns up nothing. Some pieces that have gone missing for me include 60485 (axle 9L), 32002 (pin 3/4), and 87083 (axle 4L with stop). My Stud.io seems to be the latest version since it's not asking me to update it. Is this a glitch with Stud.io or could I have unknowingly changed a setting? Any help is appreciated!

UPDATE 3/1/23 I've made some progress on the digital build. I began working on the base of the rotating boom but found that the chassis is too long. In my original post's image, there is approximately an equal amount of bed length to the front and rear of the rear axles. However, my model had significantly more bed length in front of the rear axles. This was because I made the front end of the bed approximately where the front end of the gearbox is. I've shortened the rear bed by a considerable amount and made modifications to the chassis below to have the base of the boom be moved a few studs back. I was concerned that the resulting design wouldn't be as reinforced, but it seems to be braced pretty well in all directions. The previous bed length would also mean I have to make the boom very long (comparable to the length of the boom on the 42082 Rough Terrain Crane) and I don't know if a boom of that length would be stable on a model like this. The mini linear actuators on the sides are for the outriggers. I'll have to test the outrigger mechanism physically to ensure the necessary movement and strength can be achieved before incorporating it into the digital build. I'll model most of the chassis and have the instructions made for it before beginning the physical build so I won't end up having to rebuild as much. Let me know if you have any suggestions for me! Photos:

With the gearbox-controlled mechanisms on my MCI D4500CT model proving to be impractical, I did not want to just abandon the gearbox design. Because of this, I decided to incorporate it into a different vehicle. I decided that a boom truck like the following would be god for a four-output distribution gearbox: I have not seen many boom trucks in this style done in LEGO Technic. I've seen plenty of mobile cranes, knuckle boom cranes, etc, but I figured this would make for a unique build, especially as I see plenty of these here in the US. The turntable for the crane is also mounted higher up (at the same height as the roof of the cab), so that'll provide more space for mechanisms. As of right now, the chassis consists of essentially everything to the rear of the wheelchair ramp module on my MCI D4500CT model. A difference is that both rear axles are driven, as opposed to one driven axle and one tag axle. The gearbox outputs will control the outriggers, boom rotation, boom elevation, and either boom extension or winch. There can only be two functions routed through a turntable in order to allow for unlimited rotation, so one of the boom functions will have to be manual. Because the suspension design is identical to that of my MCI D4500CT model, this model will also serve as a test bed for the drivetrain and suspension on my MCI D4500CT model. If everything works well here, I can be pretty confident using this suspension design. Let me know if you have any suggestions for me! Photos:

UPDATE 1/22/23 I finally had some time to work on the model, so I built the wheelchair lift module and inserted it into the chassis. Two independent motorized functions pass through it: the wheelchair lift extension and elevation, which are controlled by the two 16L axles the wheelchair lift module slides along. Unfortunately, while my design works in theory, it will not work in practice for several reasons. The main reason is that there is an immense amount of friction in the mechanism from all the gears involved. Three 8T gears alone are used to transfer drive inside the wheelchair lift module alone for the two motorized functions, one of them being the red frictionless 8T gear that can slides along the 16L axles. This plus all the gears in the gearbox results in so much friction for the extension mechanism that I could barely turn the input gear in the gearbox by hand. I didn't test it with the motor but my guess is the linear clutch in the gearbox will start slipping before the wheelchair lift will actually move. The second reason is that there is a lot of play in the wheelchair lift elevation mechanism. Due to space constraints, the worm gear mechanism can only be housed in the chassis instead of on the extendable module. The three 8T gears and the torsion in the 16L axle results in so much play that I can practically raise the wheelchair lift to the upper position by hand without any motor input. The play in the mechanism also prevents me from being able to control its position precisely, making it very difficult to line up horizontally when retracting the wheelchair lift. It also takes several rotations of the input before the wheelchair lift even begins to raise, and when lowering, the wheelchair lift lowers a ton at once that if a passenger were to be using it, they would probably fall off. To be fair, when I was building the model in Stud.io I had realized that some of the mechanisms might not work in practice, but I decided to give it a try just to see how it goes. This is also one of my most mechanically advanced MOCs to date, from the remote-controlled 4-output distribution gearbox to the complex wheelchair lift mechanism. There's no easy fix to the issues as there will always be the issue of directing two motorized functions into a sliding module with very limited space, and even without accounting for the gearbox the friction and play issues are already very prominent. Because of this, my plan is to completely remove the wheelchair lift function and focus on the aesthetics instead (while still keeping the motorized opening door), just like my New Flyer XD60 model. This will also reduce the weight of the model and can allow me to add a second C+ XL motor for propulsion. This will also eliminate having an unrealistically large door for the wheelchair lift mechanism on the right side. Lastly, I could see more issues coming up down the line with the whole wheelchair lift setup, such as the sliding wheelchair lift door mechanism as I cannot find a place to brace the sliding door from the bottom with that space completely taken up by seats in the Stud.io model. While this was a disappointing setback for the model, especially as I already put so much work into designing it in Stud.io, it's also good that I found that it won't work effectively early on in the build before I got too deep into it. This does mean I'll have to redesign and rebuild the chassis from scratch, so it will probably be a while before my next update. Photos:

UPDATE 12/3/22 I had to rework the gearbox, which meant redesigning some of the chassis. The previous design used a worm gear for both extending/retracting and raising/lowering the wheelchair lift. Because the extension mechanism used 8-tooth gears meshing with racks along the chassis floor, it made the mechanism painfully slow - so slow you could barely see it move. The worm gear mechanism was embedded deep in the chassis, so I had to go back to the drawing board on that part. I was able to figure out a way of transferring drive to the extension mechanism with a 1:1 gear ratio, which should make the extension/retraction speed much more reasonable. The width of the model was the primary challenge of transferring drive to the wheelchair lift module. The wheelchair ramp needs to both fully extend from the chassis and fully retract into the chassis, and 7 studs of the chassis width is taken up by the ramp itself with the gear trains for the two wheelchair ramp functions made to take as little width as possible. The chassis is 17 studs wide, and the wheelchair ramp module slides along 2 16L axles transferring drive for the two functions. Being able to allow for the full range of movement while keeping the chassis robust was a challenge, but so far it looks like the chassis remains pretty rigid. As noted in my previous update, another challenge was finding a place to put the Control+ hub and have the motors' wires able to reach it. The heart of the chassis (i.e. between the front and rear axles) is divided into three main sections - the rear third is the gearbox and the middle third is the wheelchair ramp, leaving only the first third available for the hub. Thankfully, the motors' wires were just long enough to reach the hub's ports. The wires also sit high enough that I don't think they'll interfere with the extension/retraction of the wheelchair lift. I had built the wheelchair lift module prior to rebuilding the chassis and it seemed to work fine, but I will have to redesign that as well as it needed a greater range of raising/lowering motion (I already have it modeled in Stud.io). I do have to order some parts before I physically build it though. Photos:

UPDATE 11/19/22 Got a little more of the chassis built. I'm mostly just following the Stud.io model, making changes where necessary. The drive motor and attachment points for some of the seat pairs are now in place. It's not the best location for the drive motor, but it's placed just far enough for its wire to be able to reach the hub. This also leaves more room behind the rear axles for the engine model. The biggest challenges right now are to make sure the motors' wires can reach the hub and not interfere with the wheelchair lift extending out from the chassis. The hub cannot be placed any closer to the drive and gearbox motors, and their wires are stretched as far as they can (there's probably 3rd party Powered Up extension cables out there, but I want to keep this MOC 100% LEGO). I've included some screenshots of the Stud.io model with the wheels, seats, and "stainless steel" panels hidden to get a better view of the chassis. It's very densely built - nearly every inch of space is taken, and the chassis alone has nearly 3000 pieces. No room for a luggage compartment in the bottom. Photos:

Thanks! Lol, the chassis is very densely built and nearly every inch of space is taken by mechanisms or electronics. The luggage compartment space is completely taken up by the Control+ hub lol. I think the tires will be fine. The 62.4x20 tires are pretty stiff so weight shouldn't be an issue. Their rims also come in metallic silver (from set 8285) which I plan to get as they'll match the metallic silver "stainless steel" sides well. They definitely won't be cheap though...

Last year, I built a MOC of the NJ Transit New Flyer XD60 Articulated Bus. That model was a huge success, so back in August I started working on another bus model: the NJ Transit 2016-2022 MCI D4500CT Commuter Coach. I anticipate this model having a lot more functionality than my XD60 model. There will be 6 motorized functions total, 4 of which are controlled via a 4-output distribution gearbox. The model will use Control+ electronics, with a single hub powering 4 motors (1 C+ XL for drive and 3 C+ L for steering, gearbox functions and gearbox switching). The 4 motorized functions controlled via the gearbox will be opening/closing the passenger door, extending/retracting the wheelchair lift, raising/lowering the wheelchair lift, and opening/closing the wheelchair door. The model will also feature suspension on all axles. I believe the real MCI D4500CT have independent front and tag axles and a solid driven axle (not 100% sure), but a such a setup might be too complicated so I went with a live axle suspension on all axles. I also plan to include a model of the Cummins X12 engine with mini pistons, which can be removed from the chassis as the pistons won't be visible when the engine model is inside the bus. Only the 2020-2022 (plus a handful of 2019) models have the Cummins X12 engine (previous years had the Cummins ISX12 engine), so my model will be of a 2020 or newer unit, most likely 2021 as the 2021 order was by far the largest. I started designing the model in Stud.io shortly after BrickFair VA back in August, focusing primarily on the chassis. The biggest challenge was making sure the wheelchair lift can fully extend/retract from the chassis and not interfere with any other mechanisms. The wheelchair lift's transverse range of motion takes up almost the entire width of the bus, so it was difficult making sure I can squeeze all the functionality in there without compromising on looks. Making sure I had the space to fit everything was also a challenge, as the distribution gearbox and Control+ hub both take up a lot of space. I have a preliminary version of the chassis modeled in Stud.io, and have begun building the physical model. The chassis is a very dense build, with plenty of mechanisms running through it. I also have the "stainless steel" side panels (all metallic silver - definitely won't be cheap) and seats in place in the Stud.io model. The Stud.io model is already over 4000 pieces, so I think this model will easily surpass the part count of my XD60 model. Just like my XD60 model, because I am modeling it in Stud.io, I plan to publish instructions for this MOC when it's finished. I've included some photos of the physical model as of right now (I mostly just have the gearbox section done), and some screenshots of the Stud.io model showing its progress since August. Photos: