[MOC] MAN Lion's City articulated low floor bus

[Fosapifi]

It has been quite a while since I last posted here. But this Project seems to be worth sharing with you.

At 9869 parts and 8.4 kg, it is by far our largest project.

The goal was to include motorized driving and pneumatic suspension without using any of the interior space. So yes, it has a real low floor going through the whole length.

 

RC-functions:

- The third axle is driven using 4 PF L motors, 2 CaDA metal u-joints and the new LEGO heavy duty diff. We destroyed many parts while prototyping. We tried to include a 2-speed gearbox, off-center diff, no diff at all and single wheel drive. The current setup is the only one which was working in the end.

- The first axle is steered by a PF servo, located under the driver seat.

- The bus has two separate pneumatic systems. One for the suspension and one for the doors. Both have their own manometer and pump, actuated by a PF L motor. The suspension system has 2 air tanks, the door system has 1.

- The left suspension can be raised manually with a switch in the driver's cabin. The right side is operated by a PF servo. We included a check valve to enable slow kneeling. The switches are connected in such a way that the pressure in the air tanks is always kept while kneeling. The suspension system uses 22 small pneumatic cylinders and 10 shock absorbers.

- The doors are also operated by a PF servo. The second and third door can be disabled separately from the driver's cabin. The system has a total of 6 cylinders.

- We managed to hide a micro motor under a seat behind the first axle. It is used to unfold the wheelchair ramp. We used a red 9244a u-joint to hide the mechanism in the side wall.

- A total of 8 LED pairs is used for the lighting.

 

The functions are controlled by 4 s-bricks. For power supply we use one 84599 rechargeable battery box and one buwizz brick. The bus uses 14 extension wires and 14+ meters of hose.

One of the hardest challenges was to prevent the bus from bending. The floor is only 2 studs thick and has weak spots over each axle. The roof is responsible for the rigidity while only being connected to the lower section with a few liftarms. It also houses most of the technic. There are several tight spots where every millimeter is used for hoses and wires.

 

Problems:

The suspension system is very unreliable. Many of the small cylinders leak if they are unevenly loaded. We had to buy more of them than we need and still the kneeling does not work every time.

The front and rear section are only connected with one turntable in the roof and one pin in the floor which makes it hard to pick the bus up.

 

The building time was 3 years with many breaks. We wanted to replicate the exact version of the bus which is used in Munich. Unfortunately all articulated buses with 3 doors were retired during the building process. It is very disappointing that we could not build it in blue because LEGO thinks it is a good idea to use 5 different shades of blue than releasing all basic parts in one color.

 

As usual we published free building instructions at rebrickable:

https://rebrickable.com/mocs/MOC-126294/Fosapifi/man-lions-city-g-articulated-low-floor-bus/#parts

If you want to watch the instructions for entertainment, we also have a video version:

https://www.youtube.com/watch?v=GiKy4xixxmo

You can find a very ugly pneumatic plan in the instructions.

 

The bellows are a further developed version of Sariel's design:

https://www.youtube.com/watch?v=I8_YJK_WNpY

Also big shout out to the incredible CapaCity L by krolli:

https://www.eurobricks.com/forum/index.php?/forums/topic/167663-articulated-bus-like-capacityl/

 

Edited October 20, 2022 by Fosapifi

[Good old Lego builder]

Nice! I allways love busses! Great features!

[blondasek]

Wow. Nothing else I can write.

[2GodBDGlory]

Very cool! I like how you used that old red U-joint!

Could I get some more information on how the check valve works? I love seeing those old distribution blocks used in creative ways.

[Milan]

@Fosapifi put a few pictures in your post, so we can do some frontpaging.

[Fosapifi]

22 minutes ago, Milan said:

@Fosapifi put a few pictures in your post, so we can do some frontpaging.

I just uploaded one picture. Is there any possibility to upload pictures bigger than 0.1MB?

1 hour ago, 2GodBDGlory said:

Very cool! I like how you used that old red U-joint!

Could I get some more information on how the check valve works? I love seeing those old distribution blocks used in creative ways. 

While kneeling down, the air has to pass a half engaged switch. While kneeling up, the air can get straight into to the cylinders. In the beginning of the building instructions there is a pneumatic plan, which might help you.

[2GodBDGlory]

29 minutes ago, Fosapifi said:

While kneeling down, the air has to pass a half engaged switch. While kneeling up, the air can get straight into to the cylinders. In the beginning of the building instructions there is a pneumatic plan, which might help you.

Ah, I think I get that. Cool!

[Milan]

31 minutes ago, Fosapifi said:

I just uploaded one picture. Is there any possibility to upload pictures bigger than 0.1MB?

Yes.
You need to upload pictures to a image hosting site (flickr, bricksafe...) and then link them here. (then delete the one you have uploaded now, since EB does not host pictures)
More detailed instructions are on our rules and guidelines topic.

[Aleh]

Masterpiece in the way of complexity and funtionality!!

Let me assume the wheels are too small for this scale..

[Fosapifi]

1 hour ago, Milan said:

You need to upload pictures to a image hosting site (flickr, bricksafe...) and then link them here.

Done. Here are the pictures: https://bricksafe.com/pages/fosapifi/man-lions-city-articulated-low-floor-bus

[Milan]

19 minutes ago, Fosapifi said:

Done.

Not yet.
Choose a few pictures you like, and insert them in your initial post. Copy their links and paste the links directly in the post while editing it.
Delete the picture you initial uploaded to EB.
Mind the size of the images. Max allowed size is 1024x1024. Choose the option to have them near that size.

[Fosapifi]

1 hour ago, Aleh said:

Let me assume the wheels are too small for this scale..

Yes, they are. The weels are always the first part when we build a new model. The bus ended up  being 21 studs wide, because we wanted the corridor between the weels to be 5 studs wide. 19 studs would probably be more accurate.

[m00se]

Impressive how you managed to get so much functionality in there!

[Stijn]

Awesome moc. 

[Celeri]

Excellent MOC, for sure, and probably one of the best example of near-perfection MOCing. I am speechless in front of all those functions and your no-compromise way of implementing them.

Kudos!

[Aleh]

On 10/20/2022 at 7:03 PM, Fosapifi said:

Yes, they are. The weels are always the first part when we build a new model. The bus ended up  being 21 studs wide, because we wanted the corridor between the weels to be 5 studs wide. 19 studs would probably be more accurate.

Thanks for the reply! Anyway this is a cool and complex bus!

[Fosapifi]

I want to show you some more details of the bus.

The bellows are more complex than they look from the outside. The maccaroni pieces at the top need to rotate freely, while the axles have to hold the liftarms and the maccaroni pieces at the bottom. This would be very easy, if 22l axles existed. we came up with a combination of end stop axles, frictionless pins and thin liftarms with axle holes. The 1x5 liftarms simulate the extra bellows that the real bus has in the lower part of the interior.

We came up with a super compact i6 fake engine, 3x2x9 studs, which did not make it into the final model. The pistons are crank parts and the crankshaft (actually camshaft) is made out of headlight bricks. It was ment to be powered micro motor, directly from the battery box.

Two of our favorite details are the camouflage u-joint and camouflage s-brick:

[weavil]

That is great work fitting so much functions in the roof. Looks so amazing!