[TC8] Terex Luffing Jib Tower Crane

[doug72]

The crane I will be submitting is based on a Terex CTL-180-16 currently at work on a building project near where I live.

The crane has a 16 ton lifting capacity.

IMG_2522 by Doug Ridgway, on Flickr

A prototype model was built to find out if my ideas would work, determine stability and the amount of counterweight required.

This was built from parts available using the Z56 turntable.

More parts ordered including the new Z60 turntable, 15L beams and many 2Lwith axle pins.

Building commenced.

The prototype test model:

Built using jib design from the 42042 crawler crane for the tower and jib sections. Only one section of tower built as its easier to work on.

The final model will have more tower sections which are re-designed to be more uniform and the jib made slender.

Control for testing during construction done by a bank of PF switches and a AAA battery box.

Control of final model will be using the Lego Technic Control Centre which can be programmed to perform a sequence of movements automatically.

Functions:

3 PF motors: M motor for slewing jib and winding house / M motor for hook hoisting / L motor for luffing the jib.

Final model has a height of 108 cm when jib fully raised.

Outreach with jib horizontal is 58 Cm.

Contol by PF swiches or by using the Lego Technic Control Centre.

IMG_2523 by Doug Ridgway, on Flickr

Tower base:

The base is free standing and consists of a cruxiform arrangment of grey beams which support the tower.

Three PF motors are arranged on one leg with right angle drives for the shafting that runs up the side of the tower to the top of the crane.

a. Slewing: M motor driving via a worm gear meshing with a 24T clutch gear then a further 1.66:1 reduction.

b. Luffing : L motor via a 1:1 right angle drive.

c. Hoisting: M motor via a1:1 right angle drive.

IMG_2552 by Doug Ridgway, on Flickr

Edited September 21, 2015 by Doug72

[doug72]

The Tower

First tower constructed the same way as the jib on the 42042 Crawer Crane but was not satisfactory, being too flimsy and very skeletal looking.

New tower designed which is more authentic looking and stronger.

The tower is 7L x 7L x 61L high.

The drive shaft and 12T gear for slewing have to be offset for reasons explained later.

IMG_2573 by Doug Ridgway, on Flickr

Tower Top - transfer gears.

At top of the tower the shaft drives for luffing and hoisting have to connect into the centre before passing up through the turntable co-axially.

IMG_2575 by Doug Ridgway, on Flickr

Edited September 21, 2015 by Doug72

[aminnich]

I really like this MOC tower crane. I like how you have the motors at the base so you dont have to worry about the weight being a problem. My only concern is that the base is too small, but i have no idea, i have never built a tower crane before.

[doug72]

I have had no problems with the tower falling over due to sufficient "legal" Lego counterweighting.

The base could be widened or as in real life fixed onto a foundation block.

In realy tall tower cranes they are often braced by cables or tied into the side of the building.

I am also not going to attempt any lifting records rather demonstrate operation how it operates.

With jib fully luffed in and hook at min. radius it can lift two "C" batteries OK.

As the jib is luffed out the load capacity reduces just as in real life.

Edited September 21, 2015 by Doug72

[Milan]

Great entry. I like how elegant and clean it is.

I did not understand you, what is the reason you dont heighten the base section a bit? It looks like it would match the real one better if the base section would be a little bit taller.

[doug72]

Milan,

On the real crane the tower cross section is square right down to ground level where it is bolted down to heavy concrete foundations.

Hence the bracing of the bottom section of my tower.

At the moment the tower is four 15L units high, could add more sections and go higher but then problems storing and displaying it and enough parts (beams & long axles) to do that.

By using the diagonal struts I can display it on any flat surface and they are enough to prevent toppling.

See Terex drawing showin side elevation.

terex-elevation by Doug Ridgway, on Flickr

Edited September 21, 2015 by Doug72

[Milan]

I do understand about the bracing of the foundation, and now understand why it wont go much higher, even I would love to see this higher by lets say 2x or 4x 15L units. :)

[doug72]

Milan,

The finished crane has a four unit high tower, the photo on the opening page shows the test model I built to iron out any bugs before building the final version.

The completed crane is 50 Cm from Base to turntable level.

To top of jib is 108 Cm above base when luffed fully in.

It was much easier working sitting down at my work station than standing up - extra tower sections added later.

The completed model currently resides on our dining table with permission from my wife !!

Edited September 21, 2015 by Doug72

[doug72]

Drive to the Turntable Unit:

The prototype test model used a Z56 turntable but this was stiff and crane wobbled when slewing. The drive running up the side of the tower to a 8T gear meshed directly with the 56T gear ring.

Once the new Z60 turntable received this was used and found it is much smoother and steadier when slewing.

However it appears that only double bevel gears, 12T, 20T, 36T mesh OK BUT when using the 12T gear it will not mesh in the conventional location without use of a thin spacer 3L plate.

This was not successful as the 12T gear jumped out of mesh if too much load.

Finial solution was to offset the 12T gear by 3Lx 2L with a beam to stop it disengaging.

See my previous post #7 with gear 3 showing lposition of 12T gear on the Z60 ring gear.

http://www.eurobrick...howtopic=114560

This meant the drive up the side of the tower had to be offset & two 3L universal couplings required.

Then found axle required between them had to be 11L which is not made by Lego (missing from the grey axle sequence)

Solution two 5.5 axles with stop, back to back with a connecting sleeve.

IMG_2577 by Doug Ridgway, on Flickr

Edited September 22, 2015 by Doug72

[MaxSupercars]

Looks interesting... Do you use grey bionicle part or what it is for a grey part connecting the boom to superstructure?

Max...

[Milan]

Did you try worm-gear to new turntable? Can it mesh with the turntable at any position? I havent seen that in test topic.

[doug72]

Just tried it and :

NO it does not mesh with a Z60 gear ring - see photo.

At 1L spacing existing worm meshes OK with a Z56 gear ring BUT NOT with a Z60 gear - note the bent axle.

The worm with the red bushes show it does not line up with holes in the 7 x 5 grey frame - again about 1/2L out.

So Lego needs to design a new larger diam, worm gear to mesh with the Z60 turntable at 2L spacing.

IMG_2579 by Doug Ridgway, on Flickr

This contest has resurrected my boyhood passion for building cranes using Meccanno.

Have several indeas for future cranes to build.

Edited September 22, 2015 by Doug72

[doug72]

Looks interesting... Do you use grey bionicle part or what it is for a grey part connecting the boom to superstructure?

Max...

Its a LEGO Technic Connector Block 3 x 3 Triangular with Crossaxle (32175)

I have added to it a grey Angle connector #1 to the axle part to give extra support for te jib pivots.

Edited September 22, 2015 by Doug72

[TheItalianBrick]

NO it does not mesh with a Z60 gear ring - see photo.

It does if you use "half stud" distances. But then it gets complicated in other ways.......

To be honest the new Z60 turntable is made to work with bevel gears and it does the job! Actually reduces a lot of space aswell: where you have that 5X7 frame simply put a bevel and a axle, job done!

[doug72]

Thanks for the suggestion.

Now modified the gearing for slewing the turntable using a 12T double bevel gear (grey) on a horizontal axis meshing with the turntable 60T gear ring and a 12T double bevel gear (black) on vertical axis which is on the vertical shafting down the tower. It fits OK within the same tower framework. Just had to replace two 5L beams with 7L beams and extra horizontal beam to provide strong bracing of the vertical axis gear, shafting & universal couplings were altered to suit.

It also eliminates the problem of the previous set up where the 12T gear was catching on the underside of the superstructure as it rotated.

IMG_2580 by Doug Ridgway, on Flickr

Edited September 22, 2015 by Doug72

[doug72]

Luffing & Hoist rope drums.

It was quite a challenge to fit these into 15L x 9L x 5L drum house attached to the turntable top.

From the turntable the two coaxial vertical drive shafts connect to two right angle drives to the rope drums for luffing and hoisting rope drums.

This are 3L apart but the two drive shafts to the worm gears needed to be 5L apart. This was achieved by additional reduction gear meshing directly with the 12T gear in the centre right angle drive to the luffing drum. This saved 3L and solved clearance issues with the drums.

The rope drums are are mounted one above the other.

Luffing drum has 24T clutch gear on the drum shaft.

Hoisting has 8T idler gear and 8T gear on drum shaft.

Drums are constructed using wedge pulleys and 2 x 2 round studded plates.

Some problems arose because studded technic is not wholly compatible with studless technic resulting in width issues.

Finally found a use for 14T thin bevel gears (used in old differential unit) as spacers to keep the wedge pulley drum ends rubbing on the worm gears.

Photos shows the drum unit before installing on top of the crane tower.

IMG_2564 by Doug Ridgway, on Flickr

IMG_2568 by Doug Ridgway, on Flickr

IMG_2565 by Doug Ridgway, on Flickr

IMG_2566 by Doug Ridgway, on Flickr

IMG_2567 by Doug Ridgway, on Flickr

IMG_2568 by Doug Ridgway, on Flickr

Edited September 23, 2015 by Doug72

[TheNextLegoDesinger]

looks promesing

[Sir Wolf]

I like this MOC! I especially appreciate the compact design of the drum unit. It's a technic marvel! Great job!

Also tower cranes are my second-most favourite crane, after crawler cranes. Have you thought of building

?

[doug72]

Drum unit house.

The drum house top supports the Frame for the jib luffing rope system.

A cabin with minifig crane operator along with side panels were added.

Counterweights:

To conform with the contest rules I used a Lego 88000 battery box with 6 AAA batteries plus a Lego 2 x 2 x 6 train weight mounted on a 6 x 8 studded plate that can be adjusted manually to counter balance the jib.

IMG_2581 by Doug Ridgway, on Flickr

Edited September 24, 2015 by Doug72

[Sir Wolf]

Nice work on the cabin!

[doug72]

Luffing Jib:

1st jib:- This was based on the crawler carne jib of 7 x 7 x cross section and rather skeletal. See jib on prototype test crane.

2nd jib:- 5 x 7 cross section with diagonals better located but still too wide.

IMG_2571 by Doug Ridgway, on Flickr

3rd jib:- 5 X 5 x 72L with double diagonal bracing more like the real crane jib.

This jib design also has potential for use for a horizontal tower crane jib.

An angle of jib indicator is also fitted.

I wish there were longer thin lift arms, it would make the jib lighter !

IMG_2583 by Doug Ridgway, on Flickr

The Hook:-

I have used a Lego metal hook but had to requisition it from a previous model ! They are not available from Lego and very expensive on eBay

Edited September 25, 2015 by Doug72

[doug72]

My crane - with heightened tower at 72L - is now finished and has a load hanging on the hook.

Now comes the hard part making a video !

Will have to re-arrange the shelving in my study to display the finished crane which stands 1.2m high

Now designing an alternative top section for conversion to a fixed horizontal jib tower crane that can be mounted on the existing tower section.

Jib built OK and come up with a solution to move the hoist trolly will along the beam, without the use of double drums. New drum house unit has to be built.

This will not be part of my contest entry.

Edited September 27, 2015 by Doug72

[rollermonkey]

I like this MOC! I especially appreciate the compact design of the drum unit. It's a technic marvel! Great job!

Also tower cranes are my second-most favourite crane, after crawler cranes. Have you thought of building

?

I would think that a climbing system would have to be the central design element of a build. Too many moving parts to really make the crane functional unless it was really large. Someone did it with multiple NXT units, but that one didn't have a crane on top, either.

Edited September 27, 2015 by rollermonkey

[doug72]

At the scale of my build it could only be dummy representation. I decided not to include it as the crane I have based mine on was erected by a huge mobile crane so no climbing frame was required.

The building being constructed is only four stories high on constricted site and the crane doesn't need to get any taller.

[doug72]

Update:

Due on going niggling problems with slewing smoothly I have raised the rope winding house by 1L above the rotating part of the turntable.

This ensures the slewing 12T bevel gear does not rub on the underside framing of the winding house as it rotates.

A driving ring extension cone was required due 1L change to keep all the co-axial gearing in mesh OK at the top of the tower.

This meant a complete strip down of the winding house and rebuild making it 1L higher above the T/T, it also made it 1L longer.

Universal coulplings eliminated but with 12T gear for slewing still offset.

The drive shaft now runs directly up the side of the tower and uses three 8T gears at the base to transfer the output from reduction gearing.

Found also that the white 24T clutch gear was slipping so this replaced with a plain 24T gear.

Photo shows new gearing:- note- yellow beams swung clear for clearer image.

IMG_2614 by Doug Ridgway, on Flickr

Now rotating smoothly with jib at different positions.

One thing I have learnt during this build is that everything has to be well braced and supported.

Now have to make a new video for the contest entry.

Edited October 9, 2015 by Doug72