[TC25] 42082 Rough terrain crane

[Ngoc Nguyen]

On 8/3/2023 at 3:28 AM, Akassin said:

mechanisms inside

Pardon me if this has been explained somewhere else, but why are there bidirectional gearboxes if all functions are supposedly manual? I'm thinking that giving each function its own input and knob can allow the player to control multiple functions at the same time, while freeing up space for simpler drivetrains and structural reinforcements.

Edited August 4, 2023 by Ngoc Nguyen

[Akassin]

Thanks for the feedback!

10 hours ago, MangaNOID said:

Although your missing one thing...a chassis full of rainbow 

This is necessarily a penalty point for non-compliance with the original 

1 hour ago, Ngoc Nguyen said:

Pardon me if this has been explained somewhere else, but why are there bidirectional gearboxes if all functions are supposedly manual? I'm thinking that giving each function its own input and knob can allow the player to control multiple functions at the same time, while freeing up space for simpler drivetrains and structural reinforcements.

Only to match the original. If I couldn't fit all the necessary gearboxes inside, then the failure of the reverse in the gearbox is probably the first thing I would refuse

 

[Akassin]

The simplest part of the 42082 set: the crane - is ready. Now the hardest part is ahead - building a house. 
  Since the last update, I have completely redone the top. Because the assembly of real bricks showed a weak point in one of the gears. There was also a lack of frame strength. In addition, I did not really like the previous appearance of the rear.
Now the gearbox between the functions of the lower part and the functions of the crane boom is on the left side of the turntable (this made it possible to make a good frame in the upper part and did not affect the control in any way, because this gearbox is used only at the beginning and end of the game)
A crane boom and a driver's cab were made (of course, it was not possible to make a side-sliding door on such a scale, but it opens )
Perhaps before the end of the competition I will still make minor cosmetic changes, but there will be no big adjustments.
Ahead - the final assembly of real bricks and a photo session.

Now I would like to share my impressions:
42082 was my first set after returning from the dark times and my first LEGO Technic set. Therefore, it was especially pleasant and interesting to create its alternative. My main goal was to try to keep all the functionality and principle of operation of the original set and make it as similar as possible (actually, which is the task of the contest). But in order to achieve this, a LOT of compromises had to be made. It uses assembly methods that would never be used in official Lego sets. Many elements work at the limit of their capabilities. For example - small actuators in the lower position of the boom. Yes, I could have placed them at a different angle to make things easier, but it wouldn't look right...
Also, what works well with an electric motor, works much worse in manual mode. I'm talking about gearboxes. Let me remind you that any function of the crane works through 2 gearboxes. In the picture of the internal mechanisms, you can see the number of gears ...   All this leads to a big backlash. The electric motor does the job better. It overcomes the backlash of the gears once at startup and then maintains rotation at the same speed. When you control your hands - backlash is present with every turn. Because of this, the functions work with great effort or jerks.
Also from the point of view of the game - the location of the main control knob in the rotary part of the crane is not the best idea. For example, when turning the platform, you must simultaneously rotate the knob and move your hand. But as I said at the beginning, the main goal was not to create a convenient toy, but to set myself the goal of reducing the set as it is.
But I really liked this "red baby" and I do not want to end this story on this. Therefore, immediately after sending the model to the competition, I want to make a MOC based on it. And make it as convenient, reliable and enjoyable to play as possible. I'll skip the first gearbox. As you advised me, I will remove the reverse function on the second gearbox. And I will give up everything that complicates the model, but does not make it better for the game. I'll be happy to share the result if you like it.

But it's all ahead. And it's too early to relax. After all, a gray house is waiting for me ...

And now the pictures (so far only a digital model)

Edited August 6, 2023 by Akassin

[1gor]

I can hardly await to see it in real bricks 

[2GodBDGlory]

Very, very impressive!

I've got a lot of sympathy for making overly complex models like that, even when playability suffers, so I like it a lot! Of course, the careful modeling of the body helps a lot too!

[Ngoc Nguyen]

Why dont you use red 3x11 panels for the sides of the boom?

[Thirdwigg]

Looks good. Is there some bracing for the worm gear/crane racks. It seems like the worm gear could disconnect from the rack under load.

[Akassin]

Thanks for your feedback.

16 hours ago, Ngoc Nguyen said:

Why dont you use red 3x11 panels for the sides of the boom?

I started with this, but then refused for two reasons:
1. The length of the wide part of the boom where a 3x11 panel can fit - 28 studs. 2 panels - too short, 3 - too long. Still had to add other parts.
2. the bottom of the crane boom where these panels would start was the weak point. And there is concentrated maximum load.
And I'm not sure that 3x11 panels that are not fixed on top with another liftarm will be a stronger structure than a row of three liftarms. After all, at the junction of the panels, only 1 liftarm will hold the entire weight.

40 minutes ago, Thirdwigg said:

Looks good. Is there some bracing for the worm gear/crane racks. It seems like the worm gear could disconnect from the rack under load.

I will test it under load. If there's a problem, I might be able to secure the worm gear at the end of the boom more securely at the expense of looks.

 

[Akassin]

I took a photo of the finished model.
Of the last changes - changed the gear for the winch, because the work was very slow. Added stickers from the original set.
All functions have been tested. Some work quite slowly, but this way there is less stress on the transmission. Later I will measure what maximum weight it can hold in two positions of the boom (before the model starts to damage or tip over). There will be a video later.
I hope you enjoy the result.

 

[SaperPL]

Looks awesome, a strong contender for the first place, I think. I expected the boom sides to look terrible from the studio render, but they are fine.

I don't like how the seat of operator is built, it feels like a mini sofa without cushions. I'd try to build the back and bottom separately - use a bracket with studs on the side on that door hinge structure behind the seat and attach seat back to it.  I still don't like the yellow half bushes attached by a quarter of stud onto the end of the axle in the engine. I don't know where I've seen it, either on some bricklink contest or on ideas, but I feel like it wouldn't count there as acceptable technique.

Apart from it I wonder if those two small linear actuators are enough to lift an actual weight with the boom extended. I remember I had a problem with a single one and half as big boom in my mini mobile crane and had to double that.

Whole thing looks really good though and I want to see the video. Great job :)

[1gor]

It looks very good indeed. This could be next official set like mini Unimog, or mini Xerion...

Edited August 10, 2023 by 1gor

[Akassin]

7 hours ago, SaperPL said:

Looks awesome, a strong contender for the first place, I think. I expected the boom sides to look terrible from the studio render, but they are fine.

I don't like how the seat of operator is built, it feels like a mini sofa without cushions. I'd try to build the back and bottom separately - use a bracket with studs on the side on that door hinge structure behind the seat and attach seat back to it.  I still don't like the yellow half bushes attached by a quarter of stud onto the end of the axle in the engine. I don't know where I've seen it, either on some bricklink contest or on ideas, but I feel like it wouldn't count there as acceptable technique.

Apart from it I wonder if those two small linear actuators are enough to lift an actual weight with the boom extended. I remember I had a problem with a single one and half as big boom in my mini mobile crane and had to double that.

Whole thing looks really good though and I want to see the video. Great job :)

There are so many fantastic works in this contest (including your tow truck . It is impossible to distinguish it from the original set until the image is enlarged) that it is not about the first place, but at least about the fact that the work was marked by the judges)))

Thanks for the advice on the operator's seat. I guess I was too lazy at the end of the assembly . I will definitely improve it before the final photos and videos.
About engine cylinders: I totally agree that this method would never pass quality control in an official Lego set. But as already discussed in this thread - I did not find a more compact version of the engine. Your engine design is very similar and the design of the cylinders differs only in that they do not have these half-bushings installed.
On the other hand, even in official Lego sets, there are parts that constantly fall off when playing. During this build, I had already reattached the rear view mirrors, lights and wheels many times. But believe it or not, these cylinders have not fallen off even once since installation. Well, I do not pretend to be an official set or a candidate for Lego ideas. This is just a building for a competition from an inexperienced builder 
About actuators. The actuator mechanism itself does its job well. They raise the fully extended boom from the low position. The weakest point of the entire assembly are two gearboxes. It is in them that the gears begin to crack when the critical load is reached. It is impossible to make the transfer even lower - the functions are already working very slowly. But this is what I was ready for when choosing this set. But the crane can perform its minimal functions: it lifts the wall of the house from the set (in scale) in all positions. As I wrote earlier, in order for the crane to do more - I will rebuild it after this competition.

Edited August 10, 2023 by Akassin

[SaperPL]

15 minutes ago, Akassin said:

(including your tow truck . It is impossible to distinguish it from the original set until the image is enlarged)

I guess the grass is always greener on the other side of the fence - I could say the same about your small "big red" :D

33 minutes ago, Akassin said:

On the other hand, even in official Lego sets, there are parts that constantly fall off when playing. During this build, I had already reattached the rear view mirrors, lights and wheels many times. But believe it or not, these cylinders have not fallen off even once since installation. Well, I do not pretend to be an official set or a candidate for Lego ideas.

One thing is the rigidity and parts falling off - yes, they tend to make a mess in those - but the other thing is whether something is considered a legal technique or not. If you were to create instruction for how to assemble the row of those pistons, you'll have to provide specific distance for the offset in some custom way. Similarly you shouldn't insert a pin into a thin liftarm just partially - it may not fall off, but is it the intended use of this connection type?

35 minutes ago, Akassin said:

This is just a building for a competition from an inexperienced builder 

hmm... <takes a look at three silver awards under your profile> :P

17 minutes ago, Akassin said:

About Actuators. The actuator mechanism itself does its job well. They raise the fully extended boom from the low position. The weakest point of the entire assembly are two gearboxes. It is in them that the gears begin to crack when the critical load is reached. It is impossible to make the transfer even lower - the functions are already working very slowly. But this is what I was ready for when choosing this set. But the crane can perform its minimal functions: it lifts the wall of the house from the set (in scale) in all positions.

Interesting. I was thinking this might have a problem with raising the boom under some additional load with those linear actuators. I guess the wall of the house in scale is not that big of a load. I don't remember what weights I checked for my mobile crane apart from pallet + barrel from a forklift set, so maybe I did try to pick up some heavy stuff there and remembered that wrong...

[MeLong]

amazing design

[allanp]

This is very impressive, well done 

[grum64]

Very well done indeed. I’m amazed that you’ve crammed so much into a build of this scale. Brilliant.

[Jundis]

Absolutely insane built. Hope this will be at least at podium! :-)

[Berthil]

The model looks absolutely stunning and very alike the original! Looking forward to the video to see all functions at work.

[Dylan M]

This is my Favorite entry, excellent work 👍

[Lego Tom]

The build is very well done! As for speed, people tend to forget that cranes operate slowly in the real world. Speed creates momentum, something that is undesirable and unsafe in the lifting world. It's one of the faults I have with the Liebherr LR13000 crane rotation - it is way too fast!

[Akassin]

Thank you very much for your feedback!
Before the final photos and videos, the last changes were made:
as @SaperPL advised - I changed the driver's seat. Added worm gears at the base of the boom for more reliability. The gear ratios of the gears in the winch and boom extension mechanisms were also changed.
Added video and final photos. I apologize for the too bright shots in the middle of the video (the sun appeared at the wrong time on a cloudy day). Also the video is a bit long. But I wanted to show all the functionality in detail.

 

Edited August 18, 2023 by Akassin

[Thirdwigg]

Very well done again @Akassin. You should be proud of this build. All the functionality is stunning at this scale.

[artemisovsky]

This is impressive build and a favorite to win in contest. The similarity to 42082 is very strong, it is even difficult to distinguish the original set from the shrunken one without a long comparison.

[SaperPL]

Looks really good, but what blows my mind is that cut into the telescopic gear rack assembly between two gear racks. Why not ensure that gear rack ends won't be directly matching plate ends there?

Wheels are sometimes touching the wheel archers when turning and I've also got a feeling that it's not by design, but because how weak some of the chassis structure there is. I wish Lego would already acknowledge that we should have proper steering hubs with input for this scale.

I didn't know that this set had just one motor and so many gearbox switches, that's insane. And that's a lot of cranking in your model, but I guess can't do anything about it if you want to stay true to the original.

[Mikdun]

Nicely looking build, you did great job. :)

Don't show it to Unbrickme, he will explode from gearbox complexity. 

Edited August 20, 2023 by Mikdun