[MOC] Tower Crane

[Cumulonimbus]

Hi all, I would like to present my MOC: a tower crane.

I got inspired by the 42042 B-model, but I was a bit disappointed that the trolley function (which moves the hook closer or further from the crane base) wasn't powered. While redesigning this, I got the idea to construct a tower crane from scratch. The other big inspiration is the 8288 crane. I like how it was completely cable operated and the fact that it's a small scale set large size set. I also like that modularity of the 42042, a feature I wanted to incorporate.

The goal of my efforts is a tower crane with a look and feel of a real mid-size TLG set.

Functions:

- Manual winch with ratchet system

- Manual, cable operated trolley

- Manual slew

- Modular design

The first LDD design looked like this (picture of a WIP, so the base and the trolley was not completed at this stage):

It had a lot of 6x1 thin liftarms to create the lattice boom structure of the mast and the boom. This would make it a bit flimsy and rather expensive for me to order via Bricklink. So the next step was to redesigned it to make it simpler and more rigid. For example, the 6x1 thin liftarms where replaced by 4x6 angled liftarms, which on one side are a more rigid way of bracing and on the other side can act as the connecting element between sections of a module. I also reduced the amount of modules of the mast to get the part count down (in the spirit of the MINI-contest).

This is the final model in LDD:

That is the progress so far, I'm waiting on a few Bricklink orders to start building.

EDIT: for those interested, the final part count is 744 part, including 3 strings.

Edited August 16, 2015 by Cumulonimbus

[syclone]

Looks cool!

But, isn't the base something too small?

[Kiwi_Builder]

LXF said exactly what I was thinking, it looks interesting and I'd like to see it when it's done but I agree that it needs a larger base or it will fall over extremely easily.

[Cumulonimbus]

But, isn't the base something too small?

Not sure if I agree. The base of real tower cranes are extremely small as well. Compare with this 1/87 die-cast scale model of a EC-H Liebherr crane:

A tower crane is all about equilibrium, that is why my model has room for up to five 6x2x2 train weights as counter weight in the rear. Real ones tend to have balance weights at their base as well, but since the train weights are so expensive, I want to try without them first.

Edited August 16, 2015 by Cumulonimbus

[syclone]

Thanks! Now I have it clear

[Alasdair Ryan]

Very nice crane,how about adding a jacking system/climbing frame.

They normally add concrete ballast around the base to help support it.

[Cumulonimbus]

I'll think about that climbing system, seems doable.

Some more details:

1. The routing of the three cables, blue for hoisting, greens for moving the trolley back and forth:

2.Broken down into modules:

3. Some close-ups:

Meanwhile I'm also exploring the possibility to make it RC, not really my cup of tea, but I know other AFOLs like RC.

Edited August 16, 2015 by Cumulonimbus

[Victor Imaginator]

Looks promising) Cumulonimbus, what if you use rope + pulley for supporting arm instead of 16L links? Links looks nice, but they have fixed length. While rope will balance itself with free rotating pulley. Not a critics, just a thought)

[Cumulonimbus]

This is a first try at an RC version of my crane. Some questions remain:

- Are the M-motors heavy enough to act as a counterweights?

- Is the gearing low enough?

- Are the power cables long enough and is it possible to route them nicely?

And here is a proposal for a climbing frame (made green for clarity). In real life, this can be used to let the tower crane grow without the need for a mobile crane. A new section of the mast can slide in the frame and be attached to the previous section.

I'm not sure how the lifting could be mechanised in my version without it becoming too bulky. For now it is done manually.

[MajklSpajkl]

Nice project you've got going on. I am really interested how that climbing frame will come out. I hope you'll build it for real.

[Tomik]

Interesting project - I'm courious about model built out of real bricks. I hope you'll make video too.

[Cumulonimbus]

This is a XL version: double trolleys and linked hooks, lifting frame, four section boom, four and a bit section mast, five counter weights:

And I have started building:

That's it for now, I need BL orders to come in for the rest.

[Alasdair Ryan]

For the climbing frame you could try adding a pulley like mechanism,in theory you should be able to use the crane hook to raise the crane.

I also made this in the hope it can be beneficial for a powered tower crane,I suggest using worm gears in order to keep the size down.

The idea you posted above would require extension cables and have cables running through the turntable which is not a good idea.

Download LXF Crane Idea

Edited August 17, 2015 by Alasdair Ryan

[LennyRhys]

I think it's a nice idea to use the battery box as a counterweight but I think it'll be too heavy for a Lego model of that size. Having the batteries at the bottom may be problematic as far as cables go, but it will help keep the model stable.

[MaxSupercars]

Cumulonimbus, I really enjoy your progress here... it looks very good... :) I see that you are enjoying the designing and building very much! :D :D :D

Max... ;)

[gti180]

the counter weight should also move back and forth, adds complexity I know

[Ngoc Nguyen]

How about adding the function of self-raising, like in this video? XD

[Alasdair Ryan]

How about adding the function of self-raising, like in this video? XD

Why don't you try reading the topic first before posting?

I think it's a nice idea to use the battery box as a counterweight but I think it'll be too heavy for a Lego model of that size.

The AAA / rechargeable battery boxes are very much lighter,yes you would want too move the battery box further back.

Edited August 17, 2015 by Alasdair Ryan

[Lakop]

Glad you're building it for real. Look forward to it.

H

[N-4K0]

Nice design ideas for your MOC. I love the trolley system solution, so simple and yet so clever.

Edited August 17, 2015 by Error404

[Bering]

Any updates? Very curious about this project.

[doug72]

I hope your Tower Crane project is succesfull.

Having built three tower cranes recently, it quickly became apparent there are many problems to build a reliable remotely functioning crane.

Placing all the PF components (Motors/ Battery/ IR RX plus winding drums) makes it top heavy and take up a lot of space, and I opted to place all these at the base of the crane.

Reliable movement of the hoist trolly is difficult to achieve using double drums without a lot of slack in the system due to uneven winding of the cord on & of the drums. Also the round end of technic neams causing the wheels to stick, the trolly wheels aalso tend to catch the side of the diagonal bracing when using rubber tires.

I devised a solution to overcome this using a single drive pulley and a smooth track for wheels to roll along using 8 x 1 smooth plates.

See these topics for more details.

42042 B model Lego Tower Crawler Crane (MOC) with powered hoist trolley.

http://www.eurobrick...72#entry2316131

Tower Crane (MOC) with horizontal jib

http://www.eurobrick...72#entry2348939

TC8 Tower Crane - contest entry

http://www.eurobrick...72#entry2337934

The last problem with building tall tower cranes is how and where to display them.

I had to remove two sections of shelving to accomodate them.

IMG_3112 by Doug Ridgway, on Flickr

Edited February 8, 2016 by Doug72

[Cumulonimbus]

Thank you for the interest. My crane was finished a while ago but I don't have any images at the moment. It came out pretty close to the LDD design shown here before, but I have improved some things while building. Like the 8288, I really love the fact that despite the small scale (I guess micro figure) it is still a rather tall MOC.

I never completed the climbing frame, because is became too bulky for this scale and the same is true for PF/RC.

Things I like about my creation:

- Modular construction of the whole crane

- Manual operation of the winches

Aspects which could be better:

- The torsion stiffness of the mast (the central column)

- Play in the base

[doug72]

Thank you for the interest.

Aspects which could be better:

- The torsion stiffness of the mast (the central column)

- Play in the base

Torsion or twisting of the tower was a problem on all my tower cranes especially when slewing the jib.

With original arrangement of bracing the tower it was quite flexible.

When I changed the drives to run up inside the tower I was able to put two diagonal braces opposite each other which help stiffen the tower.

Problem is only two sides of the tower can be braced, as it is difficult to attach bracing to the plain side of Technic beams.

Currently exploring ways of achieving this as sometime in the future I intend to build the crane pictured below.

Built in 1920 to lift Battleship gun turrets, it could lift up to 250 Tons.

Recently has been given a £4M full overhaul and upgrade to 375 ton lift to lift the large pipe / cable drums on to ships for the oil & wind farm industry.

Biggest challenge to to replicate all the diagonal braces and incorporate the small crane as well.

It will use the new gear racks from the BWE set for the main turntable.

IMG_3110 by Doug Ridgway, on Flickr

Edited February 8, 2016 by Doug72