[WIP] Lego technic Claas Axion Terra Trac tractor

[falconluan]

Claas published their new Axion 9 Terra trac tractor recently, I think its hood looks way better than the old one, so it's time to make a lego technic one.

 

I've built some tractor MOCs which are in scale with 107mm tractor tire at the back(you can find them at https://rebrickable.com/users/falconluan/mocs/ if you are interested). But I want to build bigger scale than them. Pitty that the 107mm tire and 14 tooth sprocket wheel are the biggest we now have available. To make something bigger while not use 3rd party parts, l chose to use tire to drive tracks in order to have a larger sprocket wheel. A simple test proved it works:

 

Then I switched to 75mm offroad tire for better traction and scale, and this is what I came with:

[falconluan]

The lastest status: Rolling chassis is finished

 

The increase of size is obvious when putting it along with 1:18 scale tractor. It certainly has different features from the smaller one, such as:

• Two PF L motors for drive instead of one
• A PF M motor will be used to select both drive modes and functions
• Drive modes and functions are switched together: High speed RWD is selected together with rear linkage, low speed AWD is selected together with rear and front PTO
• A power output connected directly with drive shaft at the back, it can be used as PTO while the standalone one can be used as simulated hydraulic output
• The front axle is completely "float" while it pivots around a fixed axis at the smaller one
• Rear linkage is controled by two small LA instead of worm gear on the smaller one

 

A demo video of its driving performance:

 

It drives well in both high speed and low speed modes. However, when hold the wheel still, the 20T gear drives rear diff will slip. Will try to switch to the new heavy duty diff to see if it can fix this.

Will work on the hood and cabin as next step.

Hope you guys like it

 

 

[Jundis]

Uhh this will be a heavy chunker! Looking forward to the progress. Please put Ackermann geometry in the steering :-P

Have you thought about a 1:18 scale version of it?

[1gor]

7 minutes ago, Jundis said:

Uhh this will be a heavy chunker! Looking forward to the progress. Please put Ackermann geometry in the steering :-P

Have you thought about a 1:18 scale version of it?

I think it is better this way to make it 1:16.5...last 3 months I have spent time developing chassis for 6300 Fastrac with 107 tires, everything is great, just one small problem - I need one stud extra in the middle and narrower tires to incorporate 6 functions - with just simple all wheel steering. So ftom 1:16.5 scale I went back to 1:15 and optimize my 4220 Fastrac..

@falconluan I hardly await to see progress on your model. Looks great so far.

Edited 3 hours ago by 1gor

[falconluan]

10 minutes ago, Jundis said:

Uhh this will be a heavy chunker!

@jundis

Yes, it will have 2000+ parts when finished I guess. I have to admit that I haven't built neither large MOC or large official set for some years, and I'm very pleased to see that the new parts TLG released these years can help that much when build large scale structure. The large frame and beams with alternating holes are very handy, they make my loads of black and gray beams in storage useless

 

20 minutes ago, Jundis said:

Please put Ackermann geometry in the steering :-P

Ackermann geometry means I will need to use the new 4L steering link, currently I'm using the old 6.5L one, and the width steering link matches the hub perfectly well. I will give it a try, since it has already many new parts on it anyway...

22 minutes ago, Jundis said:

Have you thought about a 1:18 scale version of it?

Maybe I will make one, to lineup with my current 1:18 tractor team, the shape of new hood is challenging since its shape now as other brands, becomes rather complex... even too complex for the bigger scale...

 

 

19 minutes ago, 1gor said:

 I hardly await to see progress on your model. Looks great so far.

Thank you @1gor, will keep this thread updated 

1:18 will lose some functions if you want to keep the propotion right. Tractors are too narrow in the middle...

[1gor]

2 hours ago, falconluan said:

Thank you @1gor, will keep this thread updated 

1:18 will lose some functions if you want to keep the propotion right. Tractors are too narrow in the middle...

That was the reason for me to quit my 90% finnished 8330 Fastrac - front part was compromized with Cada 94.3 tractor tires but steering angle is very small and I can not squeeze 2 motors below hood...

Edited 28 minutes ago by 1gor

[AdamFMX]

As fellow Farming Simulator player I am looking forward to result of this project. I haven't seen much AWD halftracks by the way, so it is even more interesting. I had myself built few "tractors" (better said something pretending to be tractor) with motorized functions and it is really challenge to pack everything neatly even when doing it off-scale.