[MOC] Tatra 813 6x6 V3

[yoraish]

by yoraish, on Flickr

Hi, this is the final version of Tatra 813 6x6. As written at my website:

Features a 3 speeds PF gearbox that can be replaced by a 2 speeds NXT gearbox.

After building those three other Tatra trucks I think this should be the end, at least it’s a good end. Now, this new truck is very capable and drives nicely. I think that the gearboxes help a lot and make the truck way more efficient. When I first started to build the V3 I wanted it to have a three speeds gearbox, and I achieved that. But right then I noticed a problem with the 2nd gear. Every time it had a little bit of stress over, it clicked and the truck stalled. Most of my building time was spent over fixing this problem. Eventually after all the required fixations it drove better but not yet perfect. And then a new idea struck me, why not make another gearbox with NXT motors? So I built another gearbox, which only had 2 speeds, but worked better. Because the drivetrain was so rigid all the potential problems could only happen in the gearbox. Another problem I encountered was the flexibility of the 8 tooth gears. When the firs gear was under huge stress, I could do no more, the gears themselves could not hang on. But overall the gearbox worked well.

As for the design, one of the better choices I made was to make the flat under area and the angled front. This helped keep the drivetrain safe from any high obstacles and help the truck climb over them. I believe that this is the best looking truck I’ve built so far. It has an accurate roll cage and back “thingies”. The actual cab is quiet the same as the V2 but its roof.

The suspension worked well and the truck was stable in all directions, and I guess that’s all. So to sum up we have:

6×6 drive

4×6 steering

Detailed exterior+lights

3 speeds PF gearbox

OR

2 speeds NXT gearbox

Full independent suspension.

Video:

More pictures can be found HERE.

[bricky300]

Do you will make an instruction?

[yoraish]

Do you will make an instruction?

No I won't make instructions for this model. But maybe for future ones!

[DLuders]

I don't think I have seen two different, interchangeable motor/gearbox options for the same MOC! It handles the "faceplants" well after getting over an obstacle. Do you know how much it weighs?

It appears that the Power Functions motor option has better performance than the NXT motor option -- which one do you prefer?

Edited June 4, 2011 by DLuders

[yoraish]

I actually forgot to weigh it.

I preferred the NXT gearbox because it had no design problems. But now I see that the XL motors are more efficient so I'll gear them properly next time to get maximum torque to speed efficiency.