[HELP] Articulated Steering

[Bison]

I am planning to make a big articulating tractor but I don't know how to make the steering. I need the front end to turn the way the steering wheel turn but the back end to turn the opposite way.

Here is a picture of the tractor I am planning to build( once I get more pieces )

https://encrypted-tb...S_Xaa7ybIeG9IvQ

Thanks.

[efferman]

https://www.dropbox.com/s/pmxf4dye6x1atum/bigscalewheelloaderchassis.lxf

Look at this ldd file, there is a good working articulated steering mechanism in a pretty big vehicle

[Alasdair Ryan]

Here you go,if you need a LXF file made just ask.

Edit I think I misunderstood....

Edited January 24, 2014 by Alasdair Ryan

[Bison]

Maybe a clearer picture would be nice. i think it will work.

[Alasdair Ryan]

We can do that....

[Bison]

The 12 bevel gear drives a black double bevel gear. Is that right?

[Alasdair Ryan]

Yeb that in turn drives the two black bevel gears at the steering rack.

[DrJB]

Here you go,if you need a LXF file made just ask.

Edit I think I misunderstood....

You built that (so quickly) just to answer the OP's question ... or had it build for a while? Either way, impressive!

Edited January 24, 2014 by DrJB

[Zerobricks]

Articulazed steering means the whole tractor pivots around a single central axle...

[Alasdair Ryan]

You built that (so quickly) just to answer the OP's question ... or had it build for a while? Either way, impressive!

I just built it there and then...2 mins?

[Hrafn]

I am planning to make a big articulating tractor but I don't know how to make the steering. I need the front end to turn the way the steering wheel turn but the back end to turn the opposite way.

Here is a picture of the tractor I am planning to build( once I get more pieces )

https://encrypted-tb...S_Xaa7ybIeG9IvQ

Thanks.

It's hard to tell from the small photo exactly how the steering on the real thing works, but one approach to an apparently similar tractor is here. Search the forums (and MocPages and flickr and Brickshelf) for "articulated hauler" and you'll find similar implementations. The linear actuators are probably a better solution than pneumatics, because they move slowly and can be stopped at any intermediate position; pneumatic cylinders are much harder to control precisely.

[DrJB]

Sounds like it's your lucky day, with so much expertise around. I'll add my 0.02.

The picture you're showing (is it a Case IH tractor?) shows what appears to be an articulated tractor. Articulated Tractors (and wheel-loaders) steer by rotating the front-half of the machine relative to the rear-half. The chassis itslef is made-up of two large sections, that are articulated in the middle. Strictly speaking, such large tractors have NO steerable wheels. The wheels' position is always fixed relative to the chassis (or half-chassis in this case). Such configuration is VERY different from the so-called 4WS (4 wheel steer). In 4WS vehicles, the chassis is a single bulky piece, and both rear and front tires can pivot about vertical axes. In some even older machines, the wheels do not rotate relative to their axles, but both axles pivot about their center vertical lines ...

If you are after an articulated chassis design, then look up the instructions for 8265, you can easily get them in PDF from the lego site.

Hope this helps, else, ask away.

Edit: Also, I do not recall the name of the user but, someone sometime back mad a Case Steiger 4WD tractor with lego ... might be worthwhile looking it up.

Edited January 25, 2014 by DrJB

[Kronos]

Also, I do not recall the name of the user but, someone sometime back mad a Case Steiger 4WD tractor with lego ... might be worthwhile looking it up.

Is it this one?

http://mocpages.com/moc.php/272861

Edit: Yeah thats the one. It's also here: http://www.brickshelf.com/cgi-bin/gallery.cgi?f=474751

Right dhc6twinotter?

Edited January 25, 2014 by Kronos

[dhc6twinotter]

If you don't want to use LAs, 8439 is a great set that has articulated steering and a working steering wheel. You may be able to copy the steering system from this.

D3K has an articulated steering system on his swing loader, and I believe instructions are available for it. It does use mini-LAs, and I don't think it has a working steering wheel.

Edit: Also, I do not recall the name of the user but, someone sometime back mad a Case Steiger 4WD tractor with lego ... might be worthwhile looking it up.

That may have been me. I built one a couple years ago. I don't have very good pictures of the articulation joint, but here are a few pictures (assuming stupid new flickr works):

That was before mini-LAs came out, and if I were to do it again, I'd probably use mini-LAs. No working steering wheel with this model either.

[Gee]

Hey DHC6 - I love that chassis. Neat solution to being pendular and having steering. I may nick that idea for my next MOC!

OP - Check out Sariel's BV-a-like. It has a hinge between cabs that is a bit different to what's currently been shown and provides plenty of degrees of movement and articulation. Steers via gears as opposed to LAs.

http://sariel.pl/201...gglunds-bv-206/

You can see it working clearly in the video.

Edit:

Here's another example of articulated steering which is different again:

Edited January 25, 2014 by Gee

[efferman]

and my version from post two

and a different steering method

http://www.brickshelf.com/cgi-bin/gallery.cgi?f=401452

[Gee]

That BV steering is genius Efferman! Especially in such a small space. This is a great little thread, shows just how many different ways there are to skin a cat.

[D3K]

My swingloader used some very good geometry I got from jorgeopesi, with two small LA's. I actually did implement a working steering wheel as well, using a very simple mechanism, driven by the inner gear of a large turntable:-)

[Bison]

The picture you're showing (is it a Case IH tractor?)

No Its a Massey Ferguson 5200.

I rather not use LAs, but I will use gears.

If you don't want to use LAs, 8439 is a great set that has articulated steering and a working steering wheel. You may be able to copy the steering system from this.

I did look at that and I think that will also work. Plus it uses most of my parts that I have!

[Mechbuilds]

Instead of creating another thread, i'm going to resurrect this. 

First question:
I need help with articulated steering! 
I'll be using two smaller linear actuators and for steering. It'll be M-motor driven. 
Does anybody have a mechanism like this i could copy and modify?

Second question:
It'll be roughly 42030 size and it's a harvester. 
Will the triangle beam support the weight or should i use two turntables? 

[LucyCol]

Check out this thread @grum64 has just built 42030 with @efferman steering mod which uses the small actuators.

[Mechbuilds]

Just now, LucyCol said:

Check out this thread @grum64 has just built 42030 with @efferman steering mod which uses the small actuators.

Thanks! Just what i was looking for! 

[kennywest]

I am working on the smaller brother of the one you're going to build here. It also has articulated steering and very small turning radius