Hi, I would like to show you my new MOC (technically almost one year old today, but officially unreleased yet) I have built for Truck Trial Championship (LTTT) in 2022. 

Maybe you sy to yourself now - wait - I have seen this MOC before. And youre halfway right. I re-used the "body" (cab and bed cover) from my older MOC ...

 ... but built completly new chassis. It turns out that the steering mechanism is indirectly inspired by @Zerobricks concept. 

(https://www.eurobricks.com/forum/index.php?/forums/topic/187725-wip-realistic-tatra-8x8/&tab=comments#comment-3456145) 

 

(one of the trucks on the championship used very similar steering system without the big turntable, it worked like a charm, so I applied basic engineering workflow principle - madr dome photos, and tried to improve the solution with turntable. Well, great minds probably really think alike)

 

So, finally to the MOC itself.

Mechanically, it is as simple as it could be (chasing the reliability) - no diffs, no difflocks, no switches, just 2 buggy motors, one for front, one for rear axles, mounted in the middle, geared down, connected to two drive axles like in Madoca1977's Tatra MOC. I routed the driveshafts in a way, where, in theory, the torsion in axles is partially used, together with backlash in gears, as locked differential substitute - again: in theory.
Then the steering mechanism (more photos soon), suspension - halfaxles do not turn around axis coincident with the driveshafts, light frame, detachable cab, and wire remote control to save weight.

Works good enough, the gears do not skip, but it is really a Tatra - due to ground clearance issues with low driveshaft and spine-tube placement. 

Hope you like it. 

 

More photos: https://bricksafe.com/pages/horcikdesigns/tatra-t813-8x8-lttt-v2 

More photos of the chassis will be released in near future. I also consider making instructions guide.

 

Edited February 9, 20232 yr by HorcikDesigns

Well done, when I first saw it, i thought it was a copy of my WIP, but now I see I was wrong. Do you have any more pictures of the driveline?

This Tatra looks brutal! It would be interesting to see more derails about the electronics (how many motors for propulsion is used), transmission (what is the gear ration) and total weight of the car.

@Zerobricks Thank you! More pictures will come in near future, I have to find time to make them. I also consider showing details on 3D renders, so it might cause a little delay.

@Daniel-99  It uses 2 buggymotors (mentioned in text above) and one L motor for steering. More technical details are going to be submitted with additional photos of the chassis. Total dry weight of the vehicle is something about 2.4 kg

In the meantime you can check more action of the truck on videos from the championship, which I joined with this truck.

 

 

 

 

Edited February 10, 20232 yr by HorcikDesigns

Great trucks, great shots, I simply love it. I'm still gathering experience building smaller models, but I think this is my ultimate goal to build capable trial truck in this scale which will be able to compete in such championships.

BTW where can I find more info about this red truck with hubs made from big turntables (visible for example on last video at 0:53)? I wish to take a closer look at this solution.

@keymaker Thank you. If you would like more info about the red truck, check the videos from LTTT 2020 and 2018 seasons, this car was just growing from 4 and 6 wheeler. :D 

Here is video of some cars drying their belly after river crossing. 

https://www.instagram.com/tv/CgXBQDHI5S9/?igshid=YmMyMTA2M2Y=

 

 

Edited February 10, 20232 yr by HorcikDesigns

Really cool truck, the event in this video looks more like "Tatra Trial" :D

@Jundis thanks! Well, we like Tatras. But it eas not only about them, and the most successful cars were not inspired by tatra suspension. 

What are the rules for these competitions, they seem interesting.

I see lots of models with exposed gears at the bottom, I would suggest you try to cover them as much as possible, it really makes a difference.

@Zerobricks official rues of the championship are proclaimed to be as close to the rules of the "big" trial as tehy could be, while as the refference is taken Czech Truck Trial events.
That means, that the rules of the LTTT (Lego Technic truck trial) are quite complex, but basically - you can not touch the car while in section, you can not leave the section other way than exit gate, and all gates are directional - it is defined the way the truck moves (going up or down the gate), does not matter wheter steered axles go first or last.
There are then some rules about size and weight of the vehicle in each category (class), the bumper is mandatory (expect Prototype class), and driveline scheme, etc.
Full length rules are on link below (only in czech, auto-translation needed) .
http://www.artpeter.net/trucktrial/Pravidla.php
Link to photos from older seasons: https://brickshelf.com/cgi-bin/gallery.cgi?m=KTT

Regarding the exposed gears, yes, it is issue while going through high grass or fallen wood sticks, but this way it could be much easily cleaned, and the ground clearance is usually in this scale one of the most important feature of the car.

 

 

Well, here are the promised detailed chassis photos - enjoy! - I know, there is enough space in the chassis for RC battery/control system, but remember - the batteries should last through the entire race day. ;)

Edited February 12, 20232 yr by HorcikDesigns

Hi Horcik! I recently built your V1 Tatra 8x8 and I love it! It is a very powerful machine. 

Do you still have any plans to release instructions or a LDD file for this new version? I'd love to build it - the new steering mechanism and use of buggy motors seem very exciting!

57 minutes ago, mojo_nav said:

Hi Horcik! I recently built your V1 Tatra 8x8 and I love it! It is a very powerful machine. 

Do you still have any plans to release instructions or a LDD file for this new version? I'd love to build it - the new steering mechanism and use of buggy motors seem very exciting!

Hi, glad to hear that.

I have recently finished the 3d data for chassis of the second generation, so instructions are definutely on the way. Hope to finish them this year, but I have many opened projects waiting. 

9 hours ago, HorcikDesigns said:

Hi, glad to hear that.

I have recently finished the 3d data for chassis of the second generation, so instructions are definutely on the way. Hope to finish them this year, but I have many opened projects waiting. 

Awesome! can't wait! excited to see what else you have in the pipeline