offset axles

[Dans lego]

Hello, I have been doing some research on front drive axles, it occurs to me that most if not all dont axle diffs are offset from the center of the axle, as I'm currently in the prosess of building a half realistic 4x4 chassis this information was quite importaint to me, so knowing that I started experimenting, this was the resault

has anyone used an idea like this before?

please leave any suggestions, ideas or advice below

Cheers,

-Dan

[DrJB]

That is correct. I can name the Jeep Grand Cherokee from the late 90's. Having worked specifically on that suspension, I recall the main Reason for such offset differential is that, there was no room for it to go in the middle. In the end, it does not really matter as the left/right difference in rpm is not affected by the position of the differential. I've been contemplating reproducing the Jeep's suspension myself ... but no much time lately. Keep us posted as to your progress.

Edited April 18, 2014 by DrJB

[Milan]

I used this type of offset driveshaft. There are real vehicles that used this system, too.

[PhyBuilder]

JB is right, that argument also applies to similar vehicles.

On vehicles with lots of torque it makes sense to have the differential in the middle, this because of the length of the driving axles. The longer the axle gets, more torsion needs to be withstanded. To avoid (minimal) differences in the number of NM per wheel that comes to the street as well as a (slight) difference in traction between both wheels, it's better to have it centered.

On Lego, it doesn't matter even a bit, so place it where it seems realistic. I like it the way you build it, especially for offroad cars .

[Heppeng]

Yes, 4x4's often have the front diff offset, it is usually so that the propshaft/diff can run alongside the engine/gearbox rather than underneath which would require much more clearance to allow for suspension movement. 4x4 vehicles may also have the rear diff offset to match the front as the transfer box may have both outputs in line, and it keeps all the propshafts parallel with the chassis when viewed from above. Early Range Rovers are a good example of this. It can also be an advantage when rock crawling. If both diffs sit on the right for example, you can straddle a high rock towards the left, and hopefully it will miss both diffs, gaining a valuable extra few inches of clearance.

[Hrafn]

The one downside I can think of to doing what you've pictured is that when U-joints are angled, the rotation they transmit is not at a constant speed. This means your vehicle may seem to move in a series of pulses instead of at a constant speed.

[weavil]

Also the front diff is offset on the same side as the transfer case output. This reduces the angles of the U-joints. Like in your picture, the output of the transfer case should be on the left.

[Dans lego]

Thanks guys , I shall post some updates rather soon :)

[Lipko]

The one downside I can think of to doing what you've pictured is that when U-joints are angled, the rotation they transmit is not at a constant speed. This means your vehicle may seem to move in a series of pulses instead of at a constant speed.

That's not true since there are two U-joints (and the offset axles are parallel) so one U-joint compensates the jerkiness of the other's output (only if they are placed correctly and on the posted picture they are).

[Technyk32231]

This axle can be easily be modified by changing the beam lengths on each side.

http://www.brickshelf.com/gallery/technyk32/Ideas/my_crawler_front_axle.lxf

[Dans lego]

Uhm Hi guys, Im sort of an amature here on EB, how do I post more than two or so images ? and also should I start an WIP thread for this chassis ?

now back to lego, I have some updates the axle is now a 4 link setup with panhard rod steering

[skppo]

If you want to post more pictures you need to use a hosting site for your pictures and link them in your post. Some popular sites are Brickshelf, Flickr and Imgur. I personally like Imgur. Brickshelf is specifically made for Lego images. It's downside is that you need to wait a while before your pictures become public.

Edited April 22, 2014 by skppo

[Dans lego]

If you want to post more pictures you need to use a hosting site for your pictures and link them in your post. Some popular sites are Brickshelf, Flickr and Imgur. I personally like Imgur. Brickshelf is specifically made for Lego images. It's downside is that you need to wait a while before your pictures become public.

Thanks , like moc pages ?

[Dans lego]

I finally have got around to make an Imgur account, the updated axle can be seen here

http://imgur.com/XXQKA2N

http://imgur.com/JHTotZH

Edited April 26, 2014 by Dans lego

[ms09]

Hi,

That's a nice try!

BTW, here is a 6X6 truck which I have made with three offset axles.

http://www.eurobricks.com/forum/index.php?showtopic=89986&hl=

[DrJB]

Looks nice ...

I'm wondering if this applies to the often mentioned tatra suspension ...

Can't shift side-side then fore-aft at the same time ... though there is no need for that.

Edited April 28, 2014 by DrJB