ETF Truck steering

[BobBongo1895]

Inspired by a user called sachsi from 1000steine,

this is my first attempt to build a wheel for a ETF truck.

Hope you like it and if you got any ideas or solutions for this kind of steering, please post it here.

[DLuders]

It appears that the ETF Mining Truck uses the same steering setup as the 8421 Mobile Crane (pictured below), so perhaps you could download the 8421's PDF Building Instructions to see how to do it.

[BobBongo1895]

Hmmm it´s not possible to download the instructions at the Lego page.

The steering looks simular at the picture, but what about suspension and the 10° oscillating?

[DLuders]

Oh, sorry about the bad link to the 8421's PDF Building Instructions. They are available in 6 parts on Brickset.

Modeling the ETF Advanced Hydro-pneumatic Suspension in Lego will be a big challenge! "Conventional large haul trucks have a limited suspension travel resulting in extreme forces on the main frame. ETF developed an advanced hydro-pneumatic suspension system which compensates the vehicle weight between the individual axle-lines. The extreme long suspension travel of 950 mm protects the main frame from racking (twisting). Another feature of the suspension is a better stability at negotiating curves resulting in higher permissible speeds and thus shorter trip times. The wheels always stay in contact with the road surface for optimal traction."

http://www.youtube.com/watch?v=t2FFaBPvvCo

Edited January 14, 2012 by DLuders

[BobBongo1895]

Yeah, this link is working. :-)

I compared it to the ETF version, but I think the 8421 version is not very simular.

Ok it is a small steering radius, but not so extreme.

I used something like this in this crane

Edited January 14, 2012 by BobBongo1895

[dhc6twinotter]

Looks good! I like the compact size of it.

There are different solutions for your steering. You could use a worm gear on the turntable, you could place a steering rack between this wheel module and another one directly across form it, you could use a LA to steer, or any number of other ideas.

I think one problem you will have is the lack of a differential. As the wheel module steers, one wheel will want to rotate forward, and the other backward. Placing a differential in a wheel module at this scale would be difficult, so you may be better off just having one wheel driven.

Looks like a fun project!

Edited January 14, 2012 by dhc6twinotter

[BobBongo1895]

I think one problem you will have is the lack of a differential. As the wheel module steers, one wheel will want to rotate forward, and the other backward. Placing a differential in a wheel module at this scale would be difficult, so you may be better off just having one wheel driven.

That is correct and right now the biggest problem.

[timslegos]

@dhc6twinotter

that is a good idea to only drive one wheel, that might solve a lot of problems. I like your design tho! Are you planning on making a MOC of the huge machine?

tim

[BobBongo1895]

Hey Tim,

there are no real plans for such a moc, maybe someday. Another big project will be too much for me right now.

I was just impressed by the machine and want to test the wheel assembly.

But it tingles in my fingers a bit.

[basbase]

That mining truck and possible solutions for a lego version of it have been mentioned earlier in this topic:

http://www.eurobricks.com/forum/index.php?showtopic=56994

[BobBongo1895]

Ups, sorry for the double post, I don´t saw that thread.

Could someone please close my thread?

Edited January 14, 2012 by BobBongo1895

[Burf2000]

Very cool design, are you going to make instructions?

[BobBongo1895]

Very cool design, are you going to make instructions?

Hey Simon,

I never did instructions before. But I´m able to shoot more fotos if you need more details.

[Burf2000]

Hey Simon,

I never did instructions before. But I´m able to shoot more fotos if you need more details.

That would be cool, I could see this being used for a range of things

[BobBongo1895]

Ok, I will do it tommorow morning without the tires. I need a bit of daylight for the photos.

[Burf2000]

Ok, I will do it tommorow morning without the tires. I need a bit of daylight for the photos.

Just checking you can drive and turn these wheels as it would work well for one of the things I am thinking of upscaling.

[BobBongo1895]

Hey Simon,

here as promised some pictures without the wheels.

I would suggest to turn the two black L-beams 180° and change the small 7L beams left and right to large ones, it will be stronger.

Hope it will help you.

[laix]

Has anyone ever seen some kind of prototype of the truck in real?

I'm fascinated about those trucks and the only pictures, videos and references available are renderings.

Thanks for the photos by the way.

[timslegos]

Has anyone ever seen some kind of prototype of the truck in real?

I'm fascinated about those trucks and the only pictures, videos and references available are renderings.

Thanks for the photos by the way.

I dont think it has been built yet. From what i can tell the renders are to generate interest and prospective buyers. I am guessing no company has bought one yet therefore none have been made.

tim

[Crtlego]

I have not tried building this setup, but it seems, in my humble opinion, as if the drivetrain will suffer from the use of the four black bevel gears. My past experience with heavy load vehicles tends to look down on small gears, especially those formed at an angle..

I dont think it has been built yet. From what i can tell the renders are to generate interest and prospective buyers. I am guessing no company has bought one yet therefore none have been made.

tim

I agree

[F0NIX]

Fun to see that others trying on the same project as I do :)

I have the same wheels and the turn plates, but having trouble getting the power transfer down to the wheels. I see you got a good solution but is a bit too large for my comfort. I want the wheels as close together as possible. Both the wheels on each set (thus making less need for a differential) but also each wheel set.

If you read on the website for ETF-trucks it seems like each wheel set can turn independently. Probably to enable it to crab sideways. And the independently controlled pneumatic suspension is also a bit hard to do in LEGO. So my first try is to drop the controlled suspension until the rest is good.

I'm still going to work on this.

I saw the YouTube video and immediately wanted to try to build one of these in LEGO :)

And to those who think it is a impossible project, look at my signature...

[basbase]

Alasdair and I are building dollies right now. Watch it live on:

http://brickcam.net

Edited January 20, 2012 by basbase

[Alasdair Ryan]

Sorry all i had to remove my stream my ugly face was all over it.

[basbase]

[...] I have the same wheels and the turn plates, but having trouble getting the power transfer down to the wheels. I see you got a good solution but is a bit too large for my comfort. I want the wheels as close together as possible. Both the wheels on each set (thus making less need for a differential) but also each wheel set. [...]

Here is an idea that might benefit you: an extendible axle using wedge belt wheels and axles with stop. I've used 4 large shocks to add some rigidness (soft springs will work better then the hard ones that I used). This design also fits a differential and a 3:1 gear reduction after that. I'm half way with cad instructions for it.

[efferman]

looks like the idea of a genius