[TMC]8081 6x6

[Zerobricks]

I decided to UP the things with my take on the 8081 modification contest.

Here's what I came up with:

• Driven and steered front axle with homeage to the original design
• Tandem live rear axles working on a simillar prnicipal as the front axle
• Differential lock
• Two speed gearbox
• Working steering wheel

You can see a sneak peek of the progress made in LDD:

[sirslayer]

Wow, good idea!!!!   

[Thirdwigg]

Great job. I'll be interested to see how you integrate the bodywork with this setup.

[Zerobricks]

The model is starting to materialize:

I managed to squeeze the following features inside:

1. 6x6 with longitudinal drive axles
2. Suspended pendular front suspension
3. Suspended tandem rear axles
4. Differential lock with a handle (orange)
5. Two-speed gearbox with a handle (red)
6. A working fake V4 engine
7. Working steering wheel
8. HOG input

View from the underside:

Next step is to give it a rugged, yet futuristic bodywork

Edited September 18, 2019 by Zerobricks

[Thirdwigg]

Very awesome. I'm impressed with all the features you have packed in.

[Touc4nx]

It seems pretty interesting so far, I just don't understand how the second parallel axle is driven as there is no visible gear that are connected to it from the fake engine.

 

[1gor]

Looks very interesting, but since you like number 6 (not your first small Moc with 6 wheels), I suggest you to make V6 engine...

[Zerobricks]

2 hours ago, Touc4nx said:

It seems pretty interesting so far, I just don't understand how the second parallel axle is driven as there is no visible gear that are connected to it from the fake engine.

 

The gear for secod axle is hidden under the 7L beam in front.

2 hours ago, I_Igor said:

Looks very interesting, but since you like number 6 (not your first small Moc with 6 wheels), I suggest you to make V6 engine...

I tried to fit a V6 in there, but there is simply no space left for the gearbox shifter then.

[HorcikDesigns]

Wow, looks really good so far. Keep it up!

[MajklSpajkl]

Nice and compact chassis. What does TMC stand for?

 

[1gor]

38 minutes ago, Zerobricks said:

I tried to fit a V6 in there, but there is simply no space left for the gearbox shifter then.

I had similar problem with my Moc some 5 years ago and decided to make it without gearbox / transmission...hm at the end I've ended with RC Moc...I think you know what is the best compromise.

Regards

[Zerobricks]

And here is the more or less finished model:

Notice the triple front LED lights at an angle:

The bodywork was heavily inspired by the 8081, especially the doors, hood and the side steps.

There's a triple exhaust in the rear along with the original 8081 license plate. Rear lights are also a nod to the original model.

The rear gate can open along with the cover to reveal a hidden space which can easily hold a couple of canisters:

Rear-most hatch can also hopen revealing another hidden compartment for one more canister:

Talking about opening things, the hood can be opened to reveal the V4 engine:

The doors use simple, but effective locks to keep them in place:

And here is how the model looks like with eveything opened:

The suspension can easily go over bumps, or in this case canisters:

Interrior features a functioning steering wheel and two shifters:

The orange shifter locks the central differential, while the red handle switches between the two gears:

You can see the central differential with lock in the following photo. The U-joints are for the HOG steering.

You can see the whole chassis here. Notice the curved panels used as skid plates in front and the sides

And that's about it.. This was a really fun little build, I am very suprised at the number of functions, features and detailes I managed to cram in this little model.

Well it's not such little model, final dimensions are as following:

• Length: 39cm
• Width: 15,5 cm
• Height: 16 cm
• Weight: 1100 grams

I hope you like it as much as I enjoyed building it.

Edited September 19, 2019 by Zerobricks

[Thirdwigg]

Excellent, and such a fun version. I love the opening compartments with the canisters. It great how you included such a complicated suspension. Well done.

[Touc4nx]

Wow, it's really an impressive build, that totally suit the 8081 set. 

[rm8]

Wow, just imagine. You can do papa-mobil with glassed sallon on the 6x6 chassis.)))

REbuild the WORLD!

[johnnym]

Missed that one.

On 9/19/2019 at 1:59 PM, Zerobricks said:

And here is the more or less finished model:

[...]

Nice bodywork. The door locks are really useful and simple to implement. You put the mark very high with that truck.

Some questions about the drive lines: If I understand it correctly, left and right wheels can spin at different speeds, but all wheels on one side always spin at the same speed? So a single wheel in the air won't stop/affect the other wheel on the corresponding axle? But all wheels on one side in the air and the truck stops - not that this would be a common situation and you can still lock the diff then.

Have you used such a setup in one of your motorized vehicles already? Is the off-road performance superior to per-axle diffs?

[Zerobricks]

15 minutes ago, johnnym said:

Missed that one.

Nice bodywork. The door locks are really useful and simple to implement. You put the mark very high with that truck.

Some questions about the drive lines: If I understand it correctly, left and right wheels can spin at different speeds, but all wheels on one side always spin at the same speed? So a single wheel in the air won't stop/affect the other wheel on the corresponding axle? But all wheels on one side in the air and the truck stops - not that this would be a common situation and you can still lock the diff then.

Have you used such a setup in one of your motorized vehicles already? Is the off-road performance superior to per-axle diffs?

Yes, left and right wheels are independently driven.

I used this setup in most of my new offroaders because it has following advantages:

Front and rear wheels can help each other. 

By changing the speed of each side, I can make the model steer sharper or even rotate on spot - skid steering. 

Redundancy - if one drive train fails, the model can still move with the second one.

Cancelled torque flex - because drivelines spin in opposite direction, there is no effect on suspension. 

[johnnym]

26 minutes ago, Zerobricks said:

Yes, left and right wheels are independently driven.

OK, I thought they were only connected to the differential. So when motorized you would put one motor on each other end of the drive lines?

26 minutes ago, Zerobricks said:

I used this setup in most of my new offroaders because it has following advantages:

Front and rear wheels can help each other. 

By changing the speed of each side, I can make the model steer sharper or even rotate on spot - skid steering. 

Redundancy - if one drive train fails, the model can still move with the second one.

That really works, i.e. driving with one side only? Now that's cool!

26 minutes ago, Zerobricks said:

Cancelled torque flex - because drivelines spin in opposite direction, there is no effect on suspension. 

Oh, that's useful. Sorry to bother you with a problem of mine, but could torque flex also be the reason why my black buggy (described in the part beginning with "I also created a V3 model [...]") lifts the front wheel when doing sharp turns?

[Zerobricks]

9 hours ago, johnnym said:

OK, I thought they were only connected to the differential. So when motorized you would put one motor on each other end of the drive lines?

That really works, i.e. driving with one side only? Now that's cool!

Oh, that's useful. Sorry to bother you with a problem of mine, but could torque flex also be the reason why my black buggy (described in the part beginning with "I also created a V3 model [...]") lifts the front wheel when doing sharp turns?

Yes, each driveline motorized independently.. 

If your buggy always tilts one side when accelerating, then yes, you have a lot of torque flex. 

[sirslayer]

@Zerobricks i have a question that would be helpful what is 

Suspended pendular front suspension ??

is that the default front suspension on the 8081? or is it something better?? 

thanks 

 

[Zerobricks]

Just now, sirslayer said:

@Zerobricks i have a question that would be helpful what is 

Suspended pendular front suspension ??

is that the default front suspension on the 8081? or is it something better?? 

thanks 

 

8081 uses a simillar suspension, but mine is also driven.