SaperPL

Can you show more pictures of the tractor? The roof looks kind of squashed with that rear pillars on the connectors that are shifting the axle position. I like how you did the exhaust, that's a neat detail.

Updated the studio model to current version of the bed raising mechanism: Hopefully it's clear enough to understand how it works: the 12L axles and that one 4L L-liftarm are fixed together in the platform and the platform is sliding with those 12L axle on the four pin holes over the rear axles. Sides and front axle structure (just to figure out the spacing) And finally the platform and the cab (still quickly mashed together placeholder) on top of it: I didn't realise it before, but if I want to put multiple control inputs on the roof of the cab, I might have another challenge in the cab where I need to angle those control inputs by 90 degree in tight spot between the end of the platform and front axle. Right now there's a lot of space used for the sake of using those half stud shifted steering pivot arms, but I'm not even sure that's not going to collide with front of the cab/bumper area. One thing they are doing is that they are going only half stud down below the level of the axle, which means I can have full clearance underneath the truck without anything sticking out more than the side skirts. The other approach is to use the new 2393 connector. Still, need to figure out what to do about the tow bar/tow tray mechanism.

@Ngoc Nguyen pro tip: WIN+SHIFT+S and select only portion of the screen through windows snipping tool instead of wasting real estate of your screenshots on the UI of bricklink studio and windows taskbar :)

I've taken the big chunk of the cabin from my semi truck model just to figure out where how long the whole thing would be and how tall the cabin should be for reference when building the bed, so whole thing wouldn't be weirdly stretched. Probably the front needs to be remade as it's something mostly built with system pieces and model team approach is not okay for the contest. I can ask about this, but first I'll try to do something in Technic. Surprisingly despite it being a 11 stud long flip flop beam/liftarm holding by two 15100 pins onto an axle which it's sliding on, this thing can pull up whole model around the last axle when pressed down. It's not the problem here. The problem is that it's too high and the wheel wells on the tow bar are pretty smal and tilted, and of course the mechanism itself is something I'd like to replicate more as the original one. Thanks!

I do recommend going back and forth between stud.io and physical model. Sometimes it's faster to figure out what you need to do, without physically disassembling what you already have, and also when you disassemble, having a point of reference in 3D, a backup of how it's supposed to go together, is good.

I didn't even know about the existence of this set before the contest. I just wen through the all sets historically and decided that I don't want to go for a mobile crane or other construction equipment because it'd get pretty generic quickly. Also I didn't want to make something with knuckle boom crane or excavator in a way that it'd have a knob for linear actuator at each joint rather than routing inputs to one place, so for me it was either something in the middle between simply cars and some industrial equipment and then I found this set which is awesome for me because of colors used. Btw I also tried figuring out whether I could make a supercar with suspension and a gearbox using the ball based friction CVT design, but it quickly came to a point where I realised i'll end up with something looking like a complete mess from the outside. Thanks! Yeah, like most of the contests that were about small scale models. I come back often to take a look at the cars in TC18 - that ones was really interesting, but I missed that. I like the challenge of of 9 stud wide and even 7 stud wide like others are doing, but for me it's not something that's going to be instruction worthy, so I prefer going with 11 stud wide models because steering and frames are fitting this scale well without special shenanigans.

Can you show more angles of the mechanism you got there? Good luck with pneumatic, can't wait to see how it'll work.

A few iterations later... I managed to improve the layout to have some room at the back for towing tray. Also after multiple attempts, I dropped the idea of having the knob for the bed raising at the sides under the opening/tilting panel like the original placement of gearbox switch because turning the knob that more than a flush in with sides, the bed above and panel below are sticking out for 1 stud more than the knob/12T gear that is inside. I will place the input(s) for the functions on top of the cab. Thanks to not having to make 90 degree turn in the pivot of linear actuator, I will be able to pass the second input below. The problem is that I have very little amount of space at the back and between rear wheels... For now, I managed to make a simplistic manual ^2 tow tray with rubber band loaded opening: I'm not satisfied with this for two reasons: because it has to be put together back in a cumbersome way, as well as it's not placed as in the original model where vertically it was in line with axles. Not sure though if I'll be able to fix the latter as there's really no space at the back because of two moving L-liftarms which define the tilt angle for the platform being attached at the very end down there.

Nice pick. And that wing looks good for a start. Not sure about the windshield though, the elbow pieces will look comically bulky, maybe short flebile axles/tubes would make more sense

Wow, this is going to be interesting with multiple builds going down to this scale.

Adding my trick for accessing the HOG steering on the roof of semi tractor cab:

I took some time off from other projects to make instructions for manual version of this semi tractor: Rear of the tractor got some details: The access to steering knob when trailer is attached is through a simple but neat spoiler on double-hinged mechanism which restricts the tilt angle No internal fake piston engine as I wanted to make it a rigid display/playable piece without over-complicating the structure. Free instructions on Rebrickable: https://rebrickable.com/mocs/MOC-152433

I will definitely make instructions. Also I asked few times in generic contest topic for a contest requirement of providing model for others to verify stuff. Not only because there's cool stuff being figured out, but also often photos often don't convey how sturdy or fragile the model is, and also there's potential room for "cheating" on the inside of models if there's no clear structural design verification, by doing some wacky connections that barely hold together.

Really good choice and good work so far. I would try to put slightly bigger tires on it if possible, the original had its wheels a bit dominating the looks feeling as the wheels were oversized: http://www.technicopedia.com/8865/8865side.JPG

Sculpted a bit to see how feasible it is to achieve the looks: Fitting controls for mechanisation side by side seems doable although it might have a weak connection... The bigger problem is how to implement the tray extension - not much room to do anything reasonable here. I might need to figure out something completely different than linear actuator, maybe just a sliding mechanism with some sticking out lever

Yeah, for me it would make sense if notorious winners would already sit on a jury and weren't taking part in the contest competing against us, mortals xD

And I was hoping you'd wait this one out xD

I tried doing exactly this, but I wanted to use the same size tyres as the ones at the back of a 6 stud wide semi tractor that I was building and couldn't get matching size and style tires for the front. It's either Technic parts not being there for small mechanism or the not having slim tires for specific scale. Which tyres are those btw?

You should have waited with the release of it. Also where's thy physical model? :D

@Jim, Something like this should be a promo art for the contest: But I'm not sure if LegoGlen is here on the forums. Source: https://rebrickable.com/mocs/MOC-151746/LegoGlen/wing-body-truck-23-version/#details

Wow, it took me awhile to realise those tyres are not the same thing as in the original model. I've got to get those at some point and try them out :D

You're already halfway there with the front suspension :P but let's see where it goes. Btw, here's a cool example of the steering for this kind of truck at this scale, as well as shape of the cabin: https://rebrickable.com/mocs/MOC-17765 I would check that with Jim, because you know, the Jury vote. For me it feels kind of like cheating by gluing pieces together/overhauling the axle connectors in weird way, but at the same time, someone has to be the pathfinder when it comes to new techniques :D I just realised that it's not supposed to be a hinge, but slide those axles and extend the segment there. Well, get back to what I said about mechanisms holding just on themselves :D But still, good luck, because I want to see how that arm is going to work. I'm also wondering how much the whole thing will rattle and jump when you're pumping the pneumatic system at a point in front of the first axle...

I would be worried if those two small linear actuator can pull this multi-stage boom up, it's too much load on them/for their safety mechanism, I think. I tried using one of those in a simplistic boom that is pretty lightweight and one of them wasn't enough.

I like that you're going outside->in and not inside->out as everyone else. That may be interesting to see the problems with steering vs drive shaft and how will your initial external design survive the clash :)

I like the challenge of making those kinds of models, it's always interesting to see what people come up with in tight spaces, but it feels to me like this kind of approach ends up with everything holding onto mechanisms themselves with barely any frame. I did try doing those, but usually ended up with either something being too weak or not having enough space to fit something important. My small wheeled excavator would be the prime example of that :) Aren't you afraid that handling of pneumatic controls will take too much space of the cabin? Also what is that 1 stud long pneumatic/rigid pipe acting as a pivot point for the arm? Is that cut into length and allowed or is that an actual standard lego piece?