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Hey all,

This is the crane I'm making for the TC8 competition, a Liebherr LTF 1045 truck mounted crane, mounted to an 8x4 Scania P380 chassis.

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The Liebherr LTF 1045 is a crane which is factory fitted to either an 8x4 MAN, Scania, Mercedes or Volvo chassis with the crane fitted on a Kenworth T800 in the USA. It has a lifting capability of 45 tonne and a 52m boom height when fully extended. My MOC is in scale 1/16.5 and will be fully RC. The crane's boom will be approximately 1.5 metres long when all two stages are fully extended.

The RC functions are:

  • Drive: one XL motor
  • Steering: Servo motor
  • Stabilizers folding/unfolding: M motor
  • Stabilizers extending/retracting: M motor
  • Superstructure rotation: M motor
  • Boom elevation: L or XL motor depending on space
  • Boom extension: L motor
  • Hook raising/lowering: M motor

‚ÄčOther functions:

  • Stabilizers lowering/raising: Independently controlled using pneumatics
  • Opening cab doors
  • Tilting cab (probably)
  • Straight six engine
  • Full suspension

‚Äč

Enough chat, time for some progress photos:

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Chassis with the stabilizers retracted

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And stabilizers extended and lowered

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A closeup of the stabilizer setup

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The main boom at its full length of 71 studs, with two stages going inside of it

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What I have of the first stage so far, not the actual design but just an indication of the extension length from just one of the stages.

That is my progress so far and I am currently working on improving the stabilizer design because at the moment they are too high and bulky. I will start making better progress once I get the parts I need this weekend. I'll update this thread regularly with my progress as it comes along.

As always feedback is appreciated,

Cheers :classic:

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This model has very warm feeling to me, cos this was one of my first post-dark-ages models, but in 1:13 scale..

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I can advise you right now that you pay attention to the strength of the frame and to the outriggers box, cos it holds the whole superstructure, outriggers and truck chassis together.

Also, it may be better to NOT make extending outriggers, but just the the swinging outriggers. That way it will be stronger and less complex in that crucial area.

Keep up, I will follow this one with interest!

Edited by Milan

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Update one: The Superstructure

I have been working on the superstructure and I've made some good progress.

I initially planned to have the crane in full yellow but thanks to one little panel falling on the floor and making me test with it I have ended up with having the outer boom yellow with red detailing, LBG first and second stages and a red superstructure. Sorry for not making much progress last week but I was very busy, I now have two weeks of free time to make some major progress. On Saturday I received more of the pieces that I need meaning that the boom is now completed and all in the correct colours. I'll hopefully post another update in the next couple of days or as progress occurs.

Here's the superstructure at the moment, I have the rotation motorized so far and the boom elevation is currently being worked on. The rotation is done using an M motor geared down and turning the new 60z turntable.

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Here's what it looks like with the boom sitting in its future position, it's not attached yet but it will be soon.

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Can I say something?

It's absolutely out of scale! I mean the boom lenght and size of it's section are simply too big! Seems like you are trying to impress people with big size stuff, but I'm afraid you will end up having problems to make the all thing work, the boom be able to raise and extend.

Just my impression. I hope I'm wrong! good luck anyway!

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Thanks for your thoughts. Yes, I agree that it is a bit out of scale which I'm not too surprised about given that this is my first time building anything like this :grin: The boom length is correct for the scale I'm working on (The real one extends to 48m so it's not short) but the diameter is two studs oversize in order to accommodate two stages of extension and the individual sections are so long because I can't fit four stages in the boom and still have the diameter reasonable. I'm not going for the big size to impress, this is just the scale that I build all of my creations in and it's right for the wheel size. My technique for impressing is to have the end product look good and work properly. Yes I'm definitely starting to have problems arise from the sheer size and weight of the boom. I'm working on the elevation now and I have found that I can't lift it using two large LA's geared right down from an XL motor. Because of that I'm thinking of joining two of the large new pneumatic rams end to end to get a mounting on the boom closer to the real mounting point half way along the boom instead of right at the base. We'll see how that goes once I get the brackets for connecting them. Boom extension is working perfectly at the moment, I braced every stage of the boom and used blinds cable for strength so that's not a problem.

Thanks for giving me what you think, I'm sure this thoroughly answered everything you said and I hope I can pull this all off :classic:

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Andrea, some part of the look of the giant boom might be from the distortion of the image, maybe the camera was to close to the boom, and the superstructure is far behind.

In either way, the boom does look too big, but in reality it might be a bit better.

With the boom so massive you are going to need some serious turntable. What reduction did you use from M motor to the turntable and did you try if it works?

Nice progress, although in the end you might have to (hopefully not) give up of one section in order to reduce weight of the boom.

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The M motor is geared down with a 12z half bevel gear driving a 20z half bevel gear which drives a worm gear driving an 8z gear, this turning the 60z turntable with a 12z double bevel gear to get a final reduction of 1:13.336. This gives me 13.9 RPM and that can be controlled with a speed control remote for reduced turning speed. I tested its ability to slew and it works perfectly. I do fear having to lose a section of the boom because all of the sections together weighs just under 1kg, we'll have to wait and see how that goes as everything gets joined up :wink:

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Update two: The problematic Boom

Today I worked on connecting the boom to the superstructure and rigging the second stage extension cables.

I have now found the many weight and length issues that you have warned me of, and they're causing major issues. A 160cm boom weighs a lot which puts a lot of strain on pieces and having it all stick out over a metre in front of the superstructure means that the counterweight needed it very large, I attached two battery boxes to the rear of it and that was still nowhere near enough. This is not a good sign for when it comes time to try and make the boom elevation functional.

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Because of these issues I am strongly considering changing the scale and crane model to the Liebherr LTM 1070-4.2. I was never satisfied with the carrier from this crane which is why I moved to the superstructure so this is a good opportunity to change to a completely different carrier with a similar superstructure, just a little bit narrower to fit the scale. Your input into what I should do would be appreciated :classic:

_M9P6487_8581-0_W615H615.jpg

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What scale the new carrier will be? Unless you make it much smaller, your boom issues wont be solved.

Also, arguably, pneumatics are not good aproach for a boom this size. You need something that wont be able to compress under the weight.

What you can do without adding more counterweight, is to move boom and actuator more to the back, relative to the turntable, until it is balanced.

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That's the key to it Erik. Milan, I'm thinking around the 1:23.5 mark because I saw a MOC of a very similar crane to the one I plan in that scale because the wheels are larger. I'm hoping on solving the boom issues by making it only one stage extension by removing the outer shell and making what was the first stage the new outer shell. This will remove quite a lot of weight and make the boom diameter more to scale. I thought on pneumatics because you can easily link two together end to end to get a longer ram but as you say the problem with using air means that holding it up is nigh on impossible, I went to the end to end pneumatics because two large LA's lifting the boom in parallel were unable to lift the boom due to the tiny range of motion at the base of the boom. The boom and actuator are already mounted behind the turntable and moving them any further would make it look terrible so we'll see where we end up from that problem.

At the moment I'm working on building the new carrier chassis, building the four steering, driven axles which won't feature suspension. I will get the multiple steering modes through using two Servo motors, one for the front axles and one for the rear axles. That way I can get counter-steering, crab steering, rear steering and front steering.

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You use said you used 2 battery boxes as a counter weight, my boom looks like it would be about the same size, but my counter weight idea could be a solution, i need time to do some tests and have time to do actual building and not LDD in the back of the commuter lounge at school. haha

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I'll be interested to hear what it is. Could you give me an idea of what it is? I have another week and a half of free time to test it in.

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I'm considering pulling out of the competition because I'm having too many problems. The boom's too heavy, the superstructure's too large, the carrier's too small and doesn't work very well. I have other things that I want to build and my inspiration for this is all but gone so I think I'll take my new knowledge on crane building and assist other competitors where I can instead. I've learnt a lot but I think it's time to charge on to the next thing.

It is similar to this....

http://www.miniature...hd/IMG_1184.jpg

Interesting, I'll give one of them a go for you later on.

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You cant pull out of the contest :cry_sad: I think you are doing great!! Dont give up :sweet:

I have built a very similar thing for the counter weight that is on the crane.

Edited by aminnich

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