[MOC] Concrete Mixer Truck

[ukbajadave]

The news of an official Technic concrete mixer has inspired me to finish this MOC I've been working on for a while and I thought I'd share with the community so here is my take.

This started out as an exercise in making a round shape, I had an idea to use pneumatic hose threaded through beam holes but it was pretty bad. This drum is now based on large cogs at each end wrapped in tread links with beams attached. There are also internal cross supports and a central axle so it's quite sturdy.

PF elements include:

XL motor with diff for drive.

Servo motor for virtual pivot steering.

M motor powers fake V6 and drum. The gearing down for the drum is by worm gear.

PF lights.

Manual functions include:

Cab tilt and opening doors.

Pendular front and rear suspension.

Rear concrete chute rotate, tilt and extension.

Dual rear tyres (not really a function but missing from my previous posted MOC and I'm quietly pleased I squeezed them in )

And finally of course every thread needs...

And...

Thanks for reading!

Edited February 25, 2020 by ukbajadave

[Parazels]

If I were in your shoes, I would use another scheme:

1 motor for steering;

1 motor for driving the drum and/or rear wheels (and v6 engine);

1 motor for a gearbox to select between two modes:

- drum spinning;

- drum spinning + rear wheels.

 

Also where are the small stairs between front bumper and front wheels? How does a driver get into the cabin?

Edited February 25, 2020 by Parazels

[agrof]

I really like this MOC, looks good, some neat ideas implemented. The drum is a bit out of the scale (I don't mind that though), but very Technic without using huge 1 piece molds.

Drumroll, please! 

[Ngoc Nguyen]

20 minutes ago, agrof said:

Drumroll, please

Is that a pun

[BusterHaus]

Nice MOC! Is there a mixer inside the drum? It looked empty in the video, maybe I missed it. 

[Maaboo the Witch]

Gets me hyped for 42112! Love the little details like the shovel and use of the Volvo grill as well. Cool stuff! 

[ukbajadave]

On 2/25/2020 at 3:42 PM, Parazels said:

...1 motor for driving the drum and/or rear wheels (and v6 engine);

1 motor for a gearbox to select between two modes:

- drum spinning;

- drum spinning + rear wheels.

 

...Also where are the small stairs...

I did try steps but they made the front corner a bit too messy in my eyes, and I really wanted to use the seat panels as corners :)

Looking again I am going to change those dark grey pieces to white though.

I chose the PF setup as I wanted the lights, drum and fake motor all running as soon as it was switched on and only one IR receiver for driving.There is plenty of room inside still if I wanted to add a gearbox. In fact, looking at it with fresh eyes I realise I could probably have put the servo in the main chassis and made the front axle assembly much shorter which would have aided stiffness. Oh well...

On 2/25/2020 at 5:09 PM, agrof said:

...The drum is a bit out of the scale...

Drumroll, please! 

I agree. I tend to build sub assemblies separately and then join them up later without any real planning. In this case I started out purely building a drum to see how I would do it. The size of the drum ended up being dictated by the construction of the ends. 10 tread pieces=10 segments!

Then later came everything else with the cab being very near the end and drawing on 42043 for internal structure defined the width.

19 hours ago, BusterHaus said:

...Is there a mixer inside the drum?...

Sadly not although it would be amazing to have it actually mix something! I suspect 1x1 tiles would probably drop through the gaps. Also, the drum only rotates in one direction unlike real mixers. It would be easy to add a polarity switch but there is some slack between the worm gear and drum gear and the 16z gear is pushed or pulled fractionally on the axle depending on which way it is driven (not enough for a 1/2 Bush, just enough that it might skip a tooth sometimes) so one way is smoother than the other.

Thank you all for your comments, I'm inspired to make my next MOC even better (and possibly with cab steps)