Are there any live axle 6x6 offroaders? (Also any good explanation of

[__________________________]

I am curious how 6x6 would steer around a corner, especially with a setup like this (9398 with a third axle). All axles steered.

https://docs.google.com/drawings/d/1bjoUXNip6BhAR0IJl7YnxdkfHIhLlTnRuSM0FVikprY/edit?usp=sharing

The Google Drawing above explains what I am visualizing.

how do I calculate the ideal angle for the wheels to turn at Ackerman-style?

Do other 6x6, 8x8 vehicles address this? With 8x8 it would be even worse without readjusting the wheel steering properly.

[Zerobricks]

First draw a point where you want to turn around. Usualy that point is located on a line parallel to the rear axle (if unsteered). Now steer the wheels in such a manner that their imaginary perpedicular lines all point in the same point.

Here's an example picture:

Also, here's also a picture on how to set the steering arms:

[__________________________]

First draw a point where you want to turn around. Usualy that point is located on a line parallel to the rear axle (if unsteered). Now steer the wheels in such a manner that their imaginary perpedicular lines all point in the same point.

Here's an example picture:

Very big image

Also, here's also a picture on how to set the steering arms:

Very big image

Ah thanks so my guess was right.

But once you calculate this angle, how do you adjust the steering mechanism for it?

Edited March 8, 2016 by Jim
Removed big images

[Zerobricks]

You simply offset steering point away from the wheel of the front hubs until you get an angle needed. Trial and error. But in most models I made I neglected ackermann geometry, or just used a slight ratio, which happens when using steering links. You dont have a serious advantage, especially if you have locked differentials. IMO its better to do a sturdy non-ackermann steering than a complex-easy-to break perfect ackermann steering... Depends on the use too, will you take the model offroad?

Also here's an example for 8x8:

Edited March 7, 2016 by Zblj

[jorgeopesi]

Good explanation very clever, I think I always make a mistake... my steering wheels always have the maximum possible angle, I see that is not necessary and wasted time doing it.

Edited March 7, 2016 by jorgeopesi

[__________________________]

You simply offset steering point away from the wheel of the front hubs until you get an angle needed. Trial and error. But in most models I made I neglected ackermann geometry, or just used a slight ratio, which happens when using steering links. You dont have a serious advantage, especially if you have locked differentials. IMO its better to do a sturdy non-ackermann steering than a complex-easy-to break perfect ackermann steering... Depends on the use too, will you take the model offroad?

Also here's an example for 8x8:

Model will be purely for show, showing advanced features which in reality increase fragility (gearbox, brakes, lockable differential).

How could I do Ackermann with this setup (most Ackermann I see is for 4 wheel vehicles, would it be different in this case)?

Thanks

[Zerobricks]

If you are going to use all axle steering than you need to decide where the steering point will be. I would suggest you to leave the second axle unsteered to simplify design. Than just use it as the line where the steering point will be located.

Edited March 7, 2016 by Zblj

[__________________________]

If you are going to use all axle steering than you need to decide where the steering point will be. I would suggest you to leave the second axle unsteered to simplify design. Than just use it as the line where the steering point will be located.

Hello I am building a model with wheel setup like this: https://i.ytimg.com/vi/Lvee21bpcPo/maxresdefault.jpg

Would there be a practical benefit for the second row of wheels to steer?

[Didumos69]

Hello I am building a model with wheel setup like this: https://i.ytimg.com/...xresdefault.jpg

Would there be a practical benefit for the second row of wheels to steer?

Obviously the example you are mentioning does not have steering on the second line of wheels: http://cdn.blessthis...3-amg-6x6-2.jpg

If the vehicle will only ride sand then I don't think there's a benefit. If it should be suitable for tarmac as well, then there would be. In that case the practical benefit would be a reduction of wear on all 4 rear tyres and probably better handling.

Edited March 8, 2016 by Didumos69

[Saberwing40k]

Interestingly, I have designed a 6x6 derivative of 9398. To get the right angle of the additional axle, I made it so that the wheels turned twice as far in relation to the other axles. With a six wheeled vehicle with all wheel steering, the pivot point that the vehicle would turn around would be between the two rear axles, as it would be for the standard 9398, therefore you already have your central point, and just need to have the added axle point to that. In terms of Ackerman correction, nothing special has to be done, aside from offsetting the angle of each wheel. I have built an 8x4 truck using Ackerman correction on the front axles, and the axles are identical,at least in terms of the wheel offset. Therefore, with Ackerman correction on multi axle vehicles, the pivot point is offset by the same amount on each axle, no matter where that axle is. As long as the inside wheel on each axle points at the same point, you should be fine.

[__________________________]

Obviously the example you are mentioning does not have steering on the second line of wheels: http://cdn.blessthis...3-amg-6x6-2.jpg

If the vehicle will only ride sand then I don't think there's a benefit. If it should be suitable for tarmac as well, then there would be. In that case the practical benefit would be a reduction of wear on all 4 rear tyres and probably better handling.

yes it will be a tarmac + sand vehicle.

Interestingly, I have designed a 6x6 derivative of 9398. To get the right angle of the additional axle, I made it so that the wheels turned twice as far in relation to the other axles. With a six wheeled vehicle with all wheel steering, the pivot point that the vehicle would turn around would be between the two rear axles, as it would be for the standard 9398, therefore you already have your central point, and just need to have the added axle point to that. In terms of Ackerman correction, nothing special has to be done, aside from offsetting the angle of each wheel. I have built an 8x4 truck using Ackerman correction on the front axles, and the axles are identical,at least in terms of the wheel offset. Therefore, with Ackerman correction on multi axle vehicles, the pivot point is offset by the same amount on each axle, no matter where that axle is. As long as the inside wheel on each axle points at the same point, you should be fine.

Thanks! Do you have pics of steering of your moc?

[Saberwing40k]

Which one? the one with multi axle ackerman correction, or the 3 axle 9398 derivative?

[Didumos69]

Interestingly, I have designed a 6x6 derivative of 9398. To get the right angle of the additional axle, I made it so that the wheels turned twice as far in relation to the other axles. With a six wheeled vehicle with all wheel steering, the pivot point that the vehicle would turn around would be between the two rear axles, as it would be for the standard 9398, therefore you already have your central point, and just need to have the added axle point to that. In terms of Ackerman correction, nothing special has to be done, aside from offsetting the angle of each wheel. I have built an 8x4 truck using Ackerman correction on the front axles, and the axles are identical,at least in terms of the wheel offset. Therefore, with Ackerman correction on multi axle vehicles, the pivot point is offset by the same amount on each axle, no matter where that axle is. As long as the inside wheel on each axle points at the same point, you should be fine.

When applying the images of Zblj I would argue that the wheels closest to the pair of non-steering wheels need more pivot point offset then the more distant pair of wheels. But this is only the theoratical part of course:

[Didumos69]

Someone did the Mercedes G63 AMG: http://www.moc-pages.com/moc.php/378114

[Zerobricks]

I also built the AMG 6x6 model, here's the topic:

http://www.eurobricks.com/forum/index.php?showtopic=81548&st=0

and the video: