42131 - CAT D11 Bulldozer

[kbalage]

5 minutes ago, Bartybum said:

Because for full RC pneumatics you need the same amount of electronics, in this case wouldn’t we be expecting somewhere around 500€ rather than 450€?

It could have significantly less parts than the Liebherr. That thing can only move properly on hard floor, I hope this mistake will not be made again. With a 30% piece (and weight) reduction and the same budget RC pneumatics should fit.

[Bartybum]

Just now, kbalage said:

It could have significantly less parts than the Liebherr. That thing can only move properly on hard floor, I hope this mistake will not be made again. With a 30% piece (and weight) reduction and the same budget RC pneumatics should fit.

Edited my comment just as you replied ;)

[allanp]

19 minutes ago, Bartybum said:

If it really is fully RC pneumatics, how much would the eight pneumatic cylinders, four valves, one (or even two!) pumps and PU motor cost? I feel like that’s more than just the 50€ price increase. Perhaps it’ll only have 3k pieces

Yeah, might be fewer pieces. I would gladly welcome a trade of fewer pins and beams for more of "the good stuff". 8455 is a classic example of that. But I'm not saying that it will be pneumatic or that anyone should get their hopes up for that. But there is demand for it amongst fans, they have invested in V2 pneumatics, they added the axle hole to the valves, and a new micro motor also has a lot of demand, which would be perfect for the valves. It ticks so many boxes for the next great flagship (not just any flagship) So maybe now is the time? Only time will tell I guess.

Edited January 9, 2021 by allanp

[TeamThrifty]

I love the idea of pneumatics.... but the reality always feels poor. Cranes drop like a stone and are slow to lift. You can't use for steering as air is a spring. C+ pneumatics sounds great on paper, but will the result just be a poorly functioning model?

[kbalage]

@TeamThrifty if pneumatics are used for the appropriate functions then it can work ok. In a tracked vehicle you can use 2 motors to drive the tracks directly. 4 pneumatics functions with 4 motors for the valves, 1 motor to drive the pump, and if there're 2 hubs then there's even 1 port left for a pressure sensor just for fun (NXT had that, can be done). I found a video in this EB topic, a 10 year old construction but works pretty well I think:

 

[TeamThrifty]

@kbalage yea... that looks pretty usable. My hopes are higher!!

A nice steering option would good though 

[KevinMD]

@kbalage I’m not sure how much building techniques have evolved since the studded age but what worries me about that video is the life support dangling behind the dozer that don’t see the rest of.  Not sure if it was due to limited space in the frame or what but that would be an obvious issue if they were to go the pneumatics route. With how well the blade and ripper move I assume an air tank was involved too yeah?

[2GodBDGlory]

22 hours ago, allanp said:

But there is demand for it amongst fans, they have invested in V2 pneumatics, they added the axle hole to the valves, and a new micro motor also has a lot of demand, which would be perfect for the valves.

I suppose any micro motor that would be used to control valves would have to have a rotation sensor, like the PU L and XL motors, but it seems to me that this would make the motor significantly larger. Could it have a sensor and keep the small profile, or is there an alternate way to effectively control the valves, without the sensor?

[Josephiah]

On 1/9/2021 at 5:11 PM, allanp said:

Why does it need position sensing? Most real life vehicles don't have it. That's what the driver's for!

I guess I was thinking if you were going to program it's movement at all, you won't get a reliable result because the direct connection between input and output is broken. But I'm not too au fait with the Control+ system, so I may be overestimating its capabilities!

[kbalage]

@KevinMD I guess it was controlled externally because the valves were operated manually. If you check 42080 for example the pneumatic system itself does not need too much space.

@2GodBDGlory the rotation sensor itself does not take too much space, but it is necessary to control the valve efficiently. I guess it does not need absolute positioning like the L/XL motors, but at least relative positioning (like the Boost Medium motor) is needed.

 

[allanp]

6 hours ago, TeamThrifty said:

I love the idea of pneumatics.... but the reality always feels poor. Cranes drop like a stone and are slow to lift. You can't use for steering as air is a spring. C+ pneumatics sounds great on paper, but will the result just be a poorly functioning model?

That depends on how well designed it is. For example:

This excavators digging arm looks realistically fast (yes real excavators do move that fast) and very powerful and therefore much more fun to play with, without ever dropping like a stone. For RC pneumatics it really helps to mechanically limit valve travel (to prevent dropping too quickly, although the functions of a bulldozer might not need it) and you need to have the right size pneumatics and compressor to suit the model and performance you are looking for. If you have that then they can be wonderful like the excavator seen above. 

 

[lmdesigner42]

As a way of adding more mechanical complexity, could the CAT have 2 C+ motors and a gearbox to operate the blade and ripper functions, similar to 42114? I am thinking 4 ports on the hub = 2 drive/steering motors + 2 motors for distribution gearbox. The gearbox could then output to multiple actuators for the blade and ripper, resulting in anywhere from 4-6 motorized functions including lift/tilt of the blade and ripper. It would be a logical evolution of 42114's gearbox, although it would not be realistic compared to the multiple hydraulic actuator circuits on the real thing.

[zoo]

19 hours ago, allanp said:

you need to have the right size pneumatics and compressor to suit the model and performance you are looking for. If you have that then they can be wonderful like the excavator seen above.

My guess is that LEGO pneumatics are intentionally built to leak quite a bit of air and that would have to be changed to make them work with heavier loads. Also, the hoses need to be rigid enough for minimum flex but maybe thats not a problem.

[Maaboo the Witch]

It's highly doubtful this set is gonna be pneumatic. It's more than likely gonna be a C+ version of 8275 with the CAT license and a hefty price tag slapped on top.

[howitzer]

7 minutes ago, Maaboo35 said:

It's highly doubtful this set is gonna be pneumatic. It's more than likely gonna be a C+ version of 8275 with the CAT license and a hefty price tag slapped on top.

That would be the letdown of the decade, and it has only just began.

[allanp]

1 hour ago, zoo said:

My guess is that LEGO pneumatics are intentionally built to leak quite a bit of air and that would have to be changed to make them work with heavier loads. Also, the hoses need to be rigid enough for minimum flex but maybe thats not a problem.

They can hold around 60psi or more. Which is fine and a good safe pressure for kids to play with, and quite powerful enough for any load you want to lift. You want to lift more, add a second cylinder to double the surface area and lifting force, or make the piston longer and increase the leverage. There's a solution to every problem if you look for it.

27 minutes ago, Maaboo35 said:

It's highly doubtful this set is gonna be pneumatic. It's more than likely gonna be a C+ version of 8275 with the CAT license and a hefty price tag slapped on top.

You're probably right, I won't be surprised if that's exactly what it is. But that would also be pants, and if you don't ask you don't get right? 

17 minutes ago, howitzer said:

That would be the letdown of the decade, and it has only just began.

Right on dude!

[Technicallism]

Okay, some update info about this set:

3854 pcs,   approx. €449.99

[lee1980]

29 minutes ago, Technicallism said:

Okay, some update info about this set:

3854 pcs,   approx. €449.99

oh my any word on power functions or pneumatics?

[Ngoc Nguyen]

Meanwhile 8275 has 1384 pieces. 

[Bartybum]

Could the price and piece count difference between this and the Liebherr still pay for pneumatics?

Edited January 12, 2021 by Bartybum

[allanp]

5 hours ago, Bartybum said:

Could the price and piece count difference between this and the Liebherr still pay for pneumatics?

IIRC the inclusion of pneumatics didn't raise the price of 42043, or any pneumatic set, by that much. So I guess so yeah.

[Jundis]

8 hours ago, Technicallism said:

Okay, some update info about this set:

3854 pcs,   approx. €449.99

Ok this really gets ridiculous if it's true and the dozer "only" has one smart hub and 4 motors. The 42082 had more pieces for half the price.

[allanp]

Just now, Jundis said:

Ok this really gets ridiculous if it's true and the dozer "only" has one smart hub and 4 motors. The 42082 had more pieces for half the price.

Regardless of piece count and hub/motor count, if it's just the 2007 bulldozer but bigger and with PF swapped for PU then I don't see the value there. Bigger and licenced does not necessarily equal better or more valuable to those looking for a TECHNICal marvel. Bigger only opens the door to being better but that's all.

[Bartybum]

1 hour ago, Jundis said:

Ok this really gets ridiculous if it's true and the dozer "only" has one smart hub and 4 motors. The 42082 had more pieces for half the price.

It’s still well within the realm of possibility that this set will have two hubs. I’d say it’s probable that it does.

[Maaboo the Witch]

1 hour ago, Bartybum said:

It’s still well within the realm of possibility that this set will have two hubs. I’d say it’s probable that it does.

To control a blade and ripper? Even with drive, one hub would do.