42082 - Rough Terrain Crane

[suffocation]

25 minutes ago, nerdsforprez said:

[...] and then there is jerkiness just because of backlash [...]

 

Exactly, and I wish more people would realise this. The only way to have close to zero backlash is to have the motor coupled directly to the output or at least to have a very short and simple drivetrain. The moment you start using one motor to drive multiple functions through a distribution gearbox, backlash becomes inevitable.

[TeamThrifty]

1 hour ago, Seasider said:

I'm still not sure about this set. I would have hoped for a smoother rotation of the main turntable, its very stop/start

Its back to the old 'perfection or i'm not buying' thing... i know i sound like a broken record, but sets don't need to be perfection for me, they're an ideas pack / a starting point / inspiration (either good or bad). Lego is a toy designed for being taken apart / altered / made into moc's.. thats its reason to exist, otherwise you'd glue the parts together and sit it on a shelf forever, like Tamiya kits.

But its not meant for that... its about experimentation, trial and error, learning, improving.. and not to be taken soooo seriously!! Its a hobby and a toy thats meant to be fun!!! Soooo many black clouds ... Lego, even 42070, makes me happy just looking at it.. its a rainbow, not a black cloud.. and judging by some of the colour choices, rainbows were in the design brief  !!!!

[allanp]

It does look kinda stop/start in the video, but not as bad as the BWE bucket wheel (which was due to long axles under high torque, being also driven by a chain and the fact that the teeth on the ends of the quarter ring gears are spaced just slightly too far apart). The carousel turns quite smooth as it's gear reduction is done close to the ring gear itself (so no long axles under high torque, long axles spinning fast under low torque is ok). The ring gear of the carousel is also mated/driven by a 36t double bevel gear which I suspect helps to smooth out the slightly off spacing between gear teeth where the quarter ring gear segments meet. But weirdly, it appears (though I could be wrong) that the superstructure of 42082 isn't turned via the teeth of the ring gear at all, but via the teeth of the turntable used to hold the superstructure to the base. Will that make a difference even with the lovely proper bearing? I don't know, but I think the main issue is the torturous path the power from the motor must take to get to the function of turning the superstructure. It has to go from the motor, to a upper/lower function selector gearbox, through a right angle down through a turn table, through a bidirectional function switch gearbox and back up again to turn the upper superstructure where the power from the motor started from in the first place. I like complexity but not this pointless kind of complexity which only leads to problems. Why not just have the power go from the motor, through a gearbox and then down to the turntable, like 42042?

BTW I don't think backlash is an inherent cause of jerkyness, as once the backlash is taken up it should run smooth all else being well.

Edited July 26, 2018 by allanp

[Bartybum]

Perhaps the slight jerkiness of the slewing can be fixed by adding more roller bearings and reducing the heavy load on the current 8?

Edited July 26, 2018 by Bartybum

[Jim]

1 hour ago, suffocation said:

Exactly, and I wish more people would realise this. The only way to have close to zero backlash is to have the motor coupled directly to the output or at least to have a very short and simple drivetrain. The moment you start using one motor to drive multiple functions through a distribution gearbox, backlash becomes inevitable.

That’s called compromise. Inevitable indeed. Unless you add a bag of motors. I don’t think it’s that bad btw. Some backlash and slow outriggers, but other than that it’s quite playable and functions work properly.

[AVCampos]

What about the boom lifting? Does it have the same problem as the 8043 and the 42009 due to symmetrical bevel gears driving the two LAs?

[Seasider]

It was meant as a personal comment. I was looking forward to this model as I think it looks impressive but I’d like a smoother movement when it’s rotation is powered. Just a personal preference. I was actually thinking that it was down to backlash.

so for me it puts me off a bit.

but perhaps if I find it in a sale I’ll buy it and convert it to manual for all  movement

[Timoonn]

Is that the lowest boom position?

I will not buy this set, its confirmed (not only because of that) 

Edited July 27, 2018 by Timoonn

[aminnich]

We had talked about that before. The LAs would struggle getting that heavy boom up from parallel with the ground. 

I feel like that will be one of the first things to be modified.

[Metagross555]

23 minutes ago, Timoonn said:

Is that the lowest boom position?

I will not buy this set, its confirmed 

Higher travel angle

[Timoonn]

Yeah but real ones can be lowered

[emielroumen]

18 hours ago, AVCampos said:

What about the boom lifting? Does it have the same problem as the 8043 and the 42009 due to symmetrical bevel gears driving the two LAs?

My thoughts exactly!

[TeamThrifty]

9 hours ago, Timoonn said:

Is that the lowest boom position?

I will not buy this set, its confirmed 

Cos the boom doesn't go any lower?!

[Timoonn]

No, many negative points make me follow this decision (without surprises).

The model brings nothing new compared to my 42009 (except the motorization of the rotation) and my requirements are high.

Turret rotation is slow and struggling and without self-locking mecanism without the gearbox engaged.
The weakness of stabz
The general shapes and aesthetics and especially the turret (confirmed by the video).
The lack of a true self-locking mecanism for the winch and the extension
This arm that does not go down horizontally.

And other small things

The model really has nothing transcendent for me (except these back gear racks)

This is not up to par for a model of this price range. We see the limit of making unnecessarily big models. 

But no doubts some will like this model, especially younger builders.

Edited July 27, 2018 by Timoonn

[NioN]

For those who are interested, just found a speed build building the first part of the crane: 

 

[AVCampos]

25 minutes ago, Timoonn said:

Turret rotation is slow and struggling and without self-locking mecanism without the gearbox engaged.

The 9397, 42042 and 42054 (not sure about the 42055, as I don't have it) also lack self-locking in their superstructures when disengaged. I believe that's intentional, as it's tempting for kids to rotate those large structures by hand, and a locked mechanism would break gears in that situation.

[Yevhen]

6 minutes ago, AVCampos said:

The 9397, 42042 and 42054 (not sure about the 42055, as I don't have it) also lack self-locking in their superstructures when disengaged. I believe that's intentional, as it's tempting for kids to rotate those large structures by hand, and a locked mechanism would break gears in that situation.

This set is not for kids. I doubt a teenager doesn't understand why the superstructure is locked.

[mortenm]

13 minutes ago, Yevhen said:

This set is not for kids. I doubt a teenager doesn't understand why the superstructure is locked.

10yos aren't teenagers ?

[TeamThrifty]

13 minutes ago, Yevhen said:

This set is not for kids

you have to design for the lowest common denominator - implicit assumptions lead to problems. Training literature for adults in the workplace is written as though targeting an 11 yr old, as thats deemed the safe level that most people will understand, so assuming (eek) that 'I doubt a teenager doesn't understand' is a dangerous thing to do!!

[Jim]

Just now, TeamThrifty said:

you have to design for the lowest common denominator - implicit assumptions lead to problems. Training literature for adults in the workplace is written as though targeting an 11 yr old, as thats deemed the safe level that most people will understand, so assuming (eek) that 'I doubt a teenager doesn't understand' is a dangerous thing to do!!

Wise words!  

Even though most Technic sets are for teenagers, my nephews (5 and 7) still like to play with them. 

[BrickbyBrickTechnic]

42 minutes ago, AVCampos said:

(not sure about the 42055, as I don't have it)

There's so much reduction that it is virtually self.-locking.

[fred-eric]

44 minutes ago, NioN said:

For those who are interested, just found a speed build building the first part of the crane: 

 

Thank you for the video

Same gears for the outriggers than the 42009 (12 Tooth Double Bevel and 12 Tooth Bevel)

If there are room it is maybe possible to speed them up with 20 Tooth Bevel

[TeamThrifty]

despite speed issues, the outriggers on 42009 were the best bit for me! i loved the red sliding 8t and the super long axles.. thought it was great!!

[LucyCol]

2 hours ago, Timoonn said:

No, many negative points make me follow this decision (without surprises).

The model brings nothing new compared to my 42009 (except the motorization of the rotation) and my requirements are high.

Turret rotation is slow and struggling and without self-locking mecanism without the gearbox engaged.
The weakness of stabz
The general shapes and aesthetics and especially the turret (confirmed by the video).
The lack of a true self-locking mecanism for the winch and the extension
This arm that does not go down horizontally.

And other small things

The model really has nothing transcendent for me (except these back gear racks)

This is not up to par for a model of this price range. We see the limit of making unnecessarily big models. 

At the end of the day its a childs toy, that's its market, I doubt if most care about these things 

2 hours ago, Timoonn said:

But no doubts some will like this model, especially younger builders.

I like it and at 61 it's nice to be called young  

 

 

Edited July 27, 2018 by LucyCol

[TeamThrifty]

1 minute ago, LucyCol said:

I like it and at 61 it's nice to be called young

I love it too... and i'm only 45!!