[TC8] [WIP] GSK55 Grove Trailer Crane

[aminnich]

Kiwi, how long is. was your boom. My old one was 55L with a motor at the base of the boom. but i can definitely see what your talking about, LEGOs get heavy when you add it all up.

[Saberwing40k]

With the research I did, I found that the trailer has different optional add ons to the trailer. One of which is that the last axle to a free float steering axle, I have to figure out what exactly that is but I'll probably incorporate that.

That means that the last axle would be entirely passive, only moving at the trailer moves. I think it is done by varying the caster of the wheel, such that it is negative, and effectively behind the wheel. Most vehicles have it the opposite way, because negative caster makes steering difficult, but in this case is exactly what we want. As the trailer steers, the wheels are inclined to steer, based only upon the friction of the road. Personally, I think that is one are you deviate from the real world, and make at least the last two axles steer with a servo.

[Kiwi_Builder]

Kiwi, how long is. was your boom. My old one was 55L with a motor at the base of the boom. but i can definitely see what your talking about, LEGOs get heavy when you add it all up.

My boom is the outer boom at 72 studs, first stage at 67 and second stage at 67. From what I saw of your LDD your boom has a larger diameter than mine so the 55 studs would probably weigh a similar amount to my 72. If Lego made an LA which was about 30 studs long then we wouldn't have a problem because then it would mount in a location where the only problem would be stability.

[aminnich]

If Lego made an LA which was about 30 studs long then we wouldn't have a problem because then it would mount in a location where the only problem would be stability.

Did you see my actuator idea?? i think it is a little longer than 30 studs, im not 100% sure.

@Saberwing40k; thanks for your help. I was not sure how is was going to make a true free floating axle for the trailer, i will be making the last axles (or 2) steerable with a servo

[aminnich]

smaller compact boom design, I dont want to go any smaller for the last section because i have a surprise for the end result and the last section needs to be strong.

[MaxSupercars]

Hmm that looks not bad... I like it... You make me hot to return to my mobile crane and rebuild it... :D

Max...

[Erik Leppen]

The top of the main section will separate because the pins are oriented lengthwise.

[MaxSupercars]

You're right... he has to add connection liftarms between plates lenghwise...

Max...

[Kristof]

Does this LDD planning have any sense? Since you have the parts, isn't it better to just build these drafts in real so you can test the rigidity on the go?

[aminnich]

I'm doing my LDD drawing in between my college classes. I have time this weekend to do a lot of real building

[Kristof]

I see. Makes sense then :D Just make sure it's 'between' and not 'during' :D

[aminnich]

sometimes that LEGO icon is distracting tho... HAHA

[aminnich]

I had some time today after class to do some building i have the last and second sections completed, but when i was testing the friction and such, i noticed that the last section moves side to side because of the space inside of the technic plate (5x11) as seen in the LDD picture above. So i have to figure out how to fix that.

I really want to get the chassis rebuild and finshed this weekend... high hopes but i really need that done if im going to be in this contest, im falling behind.

[Kristof]

Hmm, that problem with 5x11 panels doesn't seem to be ebvious to solve. You could insert friction pins from inside but that won't get rid of all the movement. The first option that came onto my mind was flipping these panels so they are facing inside. But that would damage the look and maybe increase the friction on the 2nd section.

By the way, do you build in realistic colors in your LDDs? Cause the cace of retracting sections is mostly black or grey. At least I have never seen yellow myself :)

[aminnich]

I'm making the boom yellow because all of my panels and curved pieces are yellow.

Thanks for your suggestion, but I don't want to flip the panel because of the change in looks.

[Kristof]

Well the very first section (outer skin) is yellow so we are talking only the 5x11 panels and some liftarms - depen's on your situation but I think it would be worthy investment to get some of these in black. Of course it's just visual side, yet it makes quite big difference in the final impression the model gives.

EDIT: Any yeah, the flipping thing was rather thought than recommendation - not the greatest option for sure.

Edited October 2, 2015 by krisandkris12

[aminnich]

Im giving the crane an over view to make sure i didnt mess a function, I found one and dont know what it is or does. It looks like a reels for a cable, but idk what the cable would be for....

[D3K]

I can't say for sure, but I think I heard somewhere that it is simply a spool of wire/line that is attached to the end of the boom, and as the boom extends, the line is unspooled. The drum is connected to an instrument to give the operator a feedback of how long the boom has been extended? In short, it's a boom-extention-indicator-device?

Again, I might have gotten this wrong, and I can't remember where I read/heard it

Edited October 2, 2015 by D3K

[aminnich]

Ok that makes sense, thanks for your quick response and help

[Kristof]

Hey, im not certainly sure but I think it's part of the anti-pendulum system on modern cranes. This is fairly complex thing including weight sensors, cable length sensor, boom elevation sensor and boom extension sensor, which is right in this spool. All the data goes to central processing unit which then controlls the superstructure rotation in order to reduce load swinging.

Btw I found some better úics of your crane in case you havent seen them already:

http://www.vertikal....ws/story/16781/

http://www.vertikal....ews/story/9259/

EDIT: missed D3K's reply first. It probably can be (and most certainly used to be) as simple as just extension meter without all the other stuff but I'm quite sure newer cranes implement that feature.

Edited October 2, 2015 by krisandkris12

[aminnich]

Another small update,

A got the chassis bare bones done, I am trying to get it close to the trailer. The next step is outriggers, then i can put in motors and the battery box. But those of you that have been following this topic, know that i have had problems with outrigger designs.

And got to set up the hook, it is a set of 3 pulleys. As for the boom section you see, that is basically it

Hope you like it

Edited October 2, 2015 by aminnich

[Cumulonimbus]

Btw I found some better úics of your crane in case you havent seen them already:

http://www.vertikal....ws/story/16781/

http://www.vertikal....ews/story/9259/

Thanks for the links, I was wondering what the advantages were of such a crane on a trailer compared to a more traditional mobile crane. In the words of the first article:

"It can be towed with its full 43 metres main boom and 10.6 tonnes of counterweight by a standard two-axle tractor, and still weigh less than 40 tonnes."

This means that: "This is the only 55 tonne capacity crane that can be transported using any normal truck so it doesn’t incur extra costs for special road permits. The total weight of the truck and trailer is only 40 tonne so it can be driven like any normal truck on all roads in Germany and many other European countries. It also enables us to travel longer distances using the shortest route possible, saving time and fuel."

The second article states that "The GSK ... is targeted at buyers that may already have a tractor unit and who do not require the off-road capability of an All Terrain crane."

Apparently, the crane is self contained, so the truck is not needed on site while lifting for several days for example

You learn something every day.

[aminnich]

the crane is self contained, so the truck is not needed on site while lifting for several days for example

That is correct, the idea is dropping the crane off at a job site and it is as functional as a mobile crane. I think it is a really cool idea!!

[aminnich]

Alright guys, here is bigger update.

I got the boom finished and it works. It is extended with all string (no gear racks). 3 sections, approximately 165 studs long fully extended. Plus the surprise, a swing jib, adds another 48 studs for a total of 213 studs. I still have to do some reinforcing on the jib, but the concept is there I hope you like it

I also started working on an outrigger system, some pictures are below, but im not sure if im keeping that design. but i still wanted to show you.

As always comments and suggestions are welcome and encouraged. Dont be too harsh tho

pictures are not the best, taken from my phone

[MaxSupercars]

Hmm... it looks good... with the jib it's a good idea... your 3. section looks pretty stiff so it shoud have no problem with the jib... Outridgers are looking also quite good... Looking forward for your next progress... :)

Max...