[MOC] Claas Xerion 5000

[GroundskeeperWillie]

Hi all, I'd like to share my first MOC, a Claas Xerion 5000 TRAC VC. It's been several years since I came out of my dark ages and ever since I've been wanting to build this particular tractor.

It looks like this:

The MOC has been close to completion for many weeks and I've been worried that someone might get inspired by the 2016 speculation topic and present a Xerion before I could finish. Well, a few days ago JBTechnic did just that without even having seen that topic. Grr...

My model features

-RC via IR

-4 wheel drive and steering (1 XL + 2 servo)

-Cabin lift and rotation

-Back PTO and linkage

-2-in-4-out switching gear box

-Crab steering mode (manually switchable)

-Front pendular suspension

Getting all those features packed into a narrow tractor is hard, especially since I have little MOC experience. So the project has been long running and I've had to learn designing in MLCad, collecting parts on Bricklink/BrickOwl as well as the actual tractor design and modeling.

Sadly, the model is not a complete success. The decision to put the IR receivers in the cabin has caused me a lot of grief and rebuilding. First, I had to buy additional extension wires and I have struggled to find space for them. Worse, the wires are both heavy and rigid which causes trouble when lifting and turning the cabin. Second, I'm not thrilled by the look of the front. JBTechnic did a great job with that in his model.

The gear box is located at the center. It is based on Sariel's gear box. I thought doing this was really clever and I needed 4 functions (lift, rotation, PTO, linkage). In reality, the gear box is rather large and it would have been far easier to find the space for 2 extra motors and an extra IR receiver. But it does work really well as long as its braced properly (and no wires get in the way).

Cabin lift is done by a small LA and rotation via a small turn table. This was fine until all the cables weigh the cabin down. Now it sometimes needs a little help.

And when turned, the cables look kinda ugly.

The cabin is partly studded.

The steering is loosely based on Madoca's SUV that I recently built. Turning a live axle into a pendular axle was quite simple. Initially, I tried using a single servo for both axles. It kinda worked but the back wheels did not always center completely because of gear slack. So my plan to extend this to crab stearing mechanically was a no go. Luckily the linkage turned out so simple, that there was just enough room for another servo in the back.

Hope you like it!

[Freekysch]

Very cool model, really like the looks and the functions of course. Congrats !

[pingel]

What a fantastic model. Getting the lift and rotate cabin in place must have been a real challenge.

How do you synchronize the switch to crab mode? This should only be possible when all wheels are aligned, right?

[MaxSupercars]

I like it... It's nice to see different approaches to the same thing... I'd like to see video if you could make... ;)

Max...

[MaxSupercars]

And another (third) Xerion from another AFOL:

Link:

http://www.brickshelf.com/cgi-bin/gallery.cgi?f=316518

Max...

Edited September 19, 2015 by MaxSupercars

[GroundskeeperWillie]

Thanks a lot guys! I thought I was done with the model but I got inspired to make a few improvements.

Also I've added a few more photos to http://www.brickshel...ry.cgi?f=559039 that I took while a had the back disassembled.

@pingel:

The PF system signal includes the position so inverting a servo via a PF switch just works, regardless of its current position. For a mechanical crab steering solution you're right, you would have to be careful to switch only in a neutral position to avoid misaligning the front and back steering angles. Also, while it now works, it still leaves the problem of actually steering left and right while in crab mode. Since my two servos are connected to the same IR channel, they cannot move independently, but that's a fair compromise of a model, I think.

@MaxSupercars:

Yes, I saw that model years ago. I liked it very much but thought it lacked the cabin lift/rotation which I think of as the defining feature of the Xerion 5000. There's also http://www.mocpages.com/moc.php/394462 (which I discovered just now) which have a lot of features but is not RC. And this http://www.eurobrick...showtopic=55879 which has a clever way to manually control steering based on a differential.

I have a few more improvements I'd like to try out and then I'll shoot a video.

[GroundskeeperWillie]

So, another update. I managed to fix most of the problems that bothered me

• Cabin rotation now uses a large turn table. This provides enough stability for the cabin to rotate and raise smoothly.
  
• The wiring now looks much better and provides less resistance for cabin movement.
  
• Video!
  

Edit: The exterior has also changed slightly:

Edited November 4, 2015 by GroundskeeperWillie

[2LegoOrNot2Lego...]

Amazing build, very well done, keep it up and thanks for sharing!

[AFOLegofan66]

this is a tractor I want to build one day!! nicejob!!

[AFOLegofan66]

Are you considering putting this on Rebrickable one day??

[GroundskeeperWillie]

Thanks 2LegoOrNot2Lego and AFOLegofan66.

Are you considering putting this on Rebrickable one day??

I don't think I'll do this in its current form. While I'm very happy with the result, it's not as good as your average MOC, I think. For one thing, the body is a bit fragile and the single XL motor is struggling just to move the tractor. I also don't have a near-complete model in MLCad so I can't provide parts list and pictures without taking it apart. And that would be opening Pandora's Box, I'm afraid

I've learned a lot, though:

1. Instead of three differentials, a better solution would be to replace the middle differential with another XL motor. This would allow it to actually move with something attached
   
2. While the sequential switching box works fine, it is not very play-friendly. You always forget which gear it's in, so if you want to start the PTO, for example, you end up messing around with the gears before you get it right. For maximum playability, i actually think going manual (not motorized) or at least manual switching would be better.
   
3. Loosing the complex switching box may also allow building slightly smaller. This would have the advantage of the wheels not looking too small.
   

But instead of doing a rebuild now, I'm really curious of how TLG will go about it in their 42054 model (http://brickset.com/sets/42054-1/Claas-Xerion-5000-Tractor). According to the speculation topic, we should get pictures in a week or so.

Unfortunately, it's unlikely I'll get any real building done before actually buying 42054 in August (small children and all).

[JBTechnic]

I fully understand! I bet every Xerion builder has the same problems, even thought it looks big there is not much room for Motors, cabin lifting etc.

I am building a Xerion in the scale of 1:16 and struggling with space.

I am impressed of all XERION Lego models I have seen so far. It challenges to find smart solutions like we do find in this model.