[PRESS RELEASE] 42109 - Top Gear Rally Car

[JonathanM]

The red gear is only 0.5 studs wide in the middle though, right? So it still takes 1L of axle (0.5 for red gear, 0.5 for bevel gear), so no problem with alignment to rims etc?

[Gray Gear]

I also think a normal lenght axle will fit just fine, 1L will go into the diff.

[SamuelYsc]

If my understanding is correct, the red gear might be not fully symmetry.
It might goes like this.

[896gerard]

16 hours ago, allanp said:

This may be an unpopular opinion but I like specialised parts. Real life vehicles are mostly built from specialised parts (by weight. There's lots of off the shelf nuts and bolts and electrical connectors but most of the weight is in large specialised parts). What I don't like is pre-assembled parts. This new diff seems to be the best of both worlds. I'm really looking forward to getting it. And is it just me or has the excitement factor of new parts been increasing lately? Starting in 2015 with the Arocs and later with the claas tyres, bucket wheel quarter gear segments, wheel arches, pneumatic valve, planetary wheel reduction hubs and now this new improved diff, they seem to have really upped their game in the new parts department. This is good because, being someone with lots of Technic pieces already, this is keeping me hooked on new sets year after year.

I fully agree. It seems like The Lego Group is listening to our needs. Look at the development of Power Functions models. At first, they only made tracked vehicles because the powertrain is more rubust, which fits TLG's requirements for child use. Then, when they saw that the adult community made motorized vehicles using differentials, they came up with the 9398 and 42030. Both had 4WD, a robust powertrain for child use. Then, when they saw the adult community makes a lot of rear wheel drive vehicles, it got them thinking. Maybe 2WD is buildable in a small Technic set. But... how to make it more robust for child (ab)use?? Hmmm... throw in a  stronger differential. The same theory holds for gearboxes. We have seen some amazing sequential gearboxes (Sheepo .. ) but it got TLG thinking: "we need to do something with this. Let's design a new part that revolutionizes gearboxes". And they did. 

This intention to overengineer parts for child use gives us, the AFOL community, a lot of much stronger parts than before. But it only started when we built things that TLG thought were impossible before. So as a general message: when we are pushing the boundaries of our parts, LEGO is watching. When it becomes popular enough, they will come up with a way of implementing it in Technic sets and they will make stronger parts for it. How nice! 

[mahjqa]

Control+ app has updated, now includes the rally car. I'm tearing the motors out of my Liebherr to build a miscolored replica to see how it works.

Edit; apparently it only dropped on Android, Apple doesn't have it yet. 

Good news: return to centre steering works excellently.

Bad news; the controller wants to mimic a real car with a gearbox. So even if you put the thing in "automatic", it pretends to cycle through different gears to accelerate. Realistic maybe, but I value speed over realism. So far, I haven't found an unbridled driving profile just yet.

Edited December 19, 2019 by mahjqa

[kbalage]

A little comparison what the 4 port Technic hub has to offer compared to the 2 port "City" Powered Up hub in the Rally Car:

 

[msk6003]

My B model out of this set.

[LegoTT]

Does the city have return to the center ?

[kbalage]

9 minutes ago, LegoTT said:

Does the city have return to the center ?

The capability is in the motor and not in the hub, although you need an app that supports it for control. Currently only the Control+ app has proper return to center steering (but that only supports the Technic hub) and the BrickController 2 app, luckily that supports even your microwave oven so problem solved :) 

[LegoTT]

Thank you

[MajklSpajkl]

16 hours ago, kbalage said:

...and the BrickController 2 app, luckily that supports even your microwave oven so problem solved :) 

 Spot on! Thank god we have @imurvai 

[Ngoc Nguyen]

I've just finished building this set. Overall a very enjoyable build.

There's a little problem with steering though. Apparently there is no kind of steering limitors, so when I steer the model to the maximum to either side, the front wheel will rub the wheel arch in the back and cant rotate. Does anyone encounter this problem?

[kbalage]

@Ngoc Nguyen check if the highlighted piece is in correct position and it's not upside down, there should not be rubbing normally:

[Ngoc Nguyen]

17 minutes ago, kbalage said:

@Ngoc Nguyen check if the highlighted piece is in correct position and it's not upside down, there should not be rubbing normally:

Mine is in the correct position. The wheel doesnt rub there though. It rubs the wheel arch in the back.

[kbalage]

@Ngoc Nguyen a photo would help to identify the issue. Normally there's always ~0.5cm gap between the front wheels and the wheel arches, regardless of the position of the wheel. 

[Ngoc Nguyen]

34 minutes ago, kbalage said:

@Ngoc Nguyen a photo would help to identify the issue. Normally there's always ~0.5cm gap between the front wheels and the wheel arches, regardless of the position of the wheel. 

 

 

[kbalage]

@Ngoc Nguyen you need to turn your wheels, the other side of the rim should be facing outwards.

[Ngoc Nguyen]

Just now, kbalage said:

@Ngoc Nguyen you need to turn your wheels, the other side of the rim should be facing outwards.

Now that makes more sense. Thanks a lot!

[johnnym]

58 minutes ago, Ngoc Nguyen said:

Now that makes more sense. Thanks a lot!

@Ngoc Nguyen: If you prefer the sprocket side of the rims facing inwards (i.e. what you did at first), it should work, when you remove the yellow half bushes - at least it does for my PF mod of this set. Similarly at the rear, removing the round plates could allow to switch the rim sides of the rear wheels, too, without (or with light) touching (of) the axle support and not too much protrusion. If the rear rims touch the axle support, I think you can still replace it with a single bush in the original construction, the axles should still have enough support at least on one side - though I don't know what happens on the side with the diff. @kbalage: What's your experience? Can the axle supports be replaced with bushes on the diff side of the rear axle w/o loosing too much support?

[kbalage]

@johnnym I see no point of removing the axle support, especially on the diff side as the vertical half beams are still there. If someone wants to turn the rims then the easiest solution is to remove the round plates, that works on both sides and as you wrote the wheels won't or will barely touch the support. Just tested it, there's no visible effect on the (otherwise spectacular) performance