Need help with a design for a powered, steerable, independent suspensi

[Dreadredbeard]

I come to you great minds to help me solve a problem I'm having with a new axle design.

I'm using the portal hubs for one last piece of reduction for the new design, but I'm having trouble adapting a driven, steerable, independent suspension that is small and strong enough to handle the abuse of a powerful 1:10 model.

These are the hubs:

The easiest solution I could configure was using these:

4523398

But since I don't currently own any I would need to go purchase 8 of them for the new model, which I would like to avoid if there is a better option. And I'm a little worried about strength with using those pieces as the only thing holding the entire hub and wheel assemblies would be two ball joints.

So has anyone designed a strong, compact, powered, steerable independent suspension using portal hubs? (quite the mouthful!)

Thank you for your help!

[pint14]

Its very, very hard to build suspension like that + it should be compact. I think you shouldnt use poratal axles. Found this but i think this is too big and not very strong.

[sten]

I would not use the portal hubs. They make the king pin axis very far from the wheel. Here is a concept that I made http://www.eurobricks.com/forum/index.php?showtopic=79819&hl= (the top one is the one applicable to your situation). I am not sure if this would be sturdy enough, but it is as compact as is possible (could shorten the arms only) and does not use the pre-made 'A' arms, while still having gear reduction at the wheel. Hopefully this gives you some ideas.

[jorgeopesi]

I built two years ago, may be can help you and with the new pieces sure you can improve them. I hate that unimog piece .

[Zerobricks]

Very easy to do... Built this in 5 mins now:

Didnt had time to align the springs, but all else should work!

You can use a diff or a 36 tooth gears for no diff.

Also it might be wise to reinforce suspension arms with 3L beams.

Steering angle should be somewhere arround 30 degrees

Edited May 30, 2013 by Zblj

[Saberwing40k]

Its very, very hard to build suspension like that + it should be compact. I think you shouldnt use poratal axles. Found this but i think this is too big and not very strong.

You should stick with the portal axles. Also, this design is plenty strong, and I should know, because I made it. Since I know the ins and outs of this design, it can be made narrower without all to much difficulty. Still, I can't think of any vehicles in real life that have independent suspension and portal axles, so if you can tell everybody what you're making, we can help you better. On the other hand, 1:10 scale is kind of big, so compactness will not be as much of an issue.

And now that I've stopped being a shameless plug, another place to look for inspiration is to look at Lego Tatra trial trucks. Some of these builds have what you need.

[AndyCW]

AM General Hummer is independant with portal hubs.

v/r

Andy

[jorgeopesi]

AM General Hummer is independant with portal hubs.

v/r

Andy

Another rare example is the pinzgauer, it uses portal and tatra axles .

[1nxtmonster]

Hello. I have built this before

Edited May 30, 2013 by 1nxtmonster

[Lipko]

You can make the A-arms stronger. I attempted to make a Hummer some time ago, here's the suspension from the bottom:

As Zblj also showed, the key is to turn the lower A-arm upside down, so it can't pop out of the hub. The biggest weakness of the design was the steering, the steering rods could pull out the ball-pins from the gear-rack due to the high suspension travel, so it's better to use the rack upside down too in that case.

A side-note Zblj's solution: the gear rack placed on the frame part like that can jam under stress. Make sure that the gear rack has a smooth base.

Edited May 30, 2013 by Lipko

[SNIPE]

Maybe you would get a larger steering angle by using the hubs from the 42000 gran prix racer or build your own from connectors.

[Dreadredbeard]

Very easy to do... Built this in 5 mins now:

Didnt had time to align the springs, but all else should work!

You can use a diff or a 36 tooth gears for no diff.

Also it might be wise to reinforce suspension arms with 3L beams.

Steering angle should be somewhere arround 30 degrees

I was originally trying to avoid using the A-arm pieces as I don't own any, but that really is the cleanest way to do it... Dang it :p

Hello. I have built this before

That is an incredibly cool design! I probably won't use it for this project but I am going to try it on one in the future.

You can make the A-arms stronger. I attempted to make a Hummer some time ago, here's the suspension from the bottom:

As Zblj also showed, the key is to turn the lower A-arm upside down, so it can't pop out of the hub. The biggest weakness of the design was the steering, the steering rods could pull out the ball-pins from the gear-rack due to the high suspension travel, so it's better to use the rack upside down too in that case.

A side-note Zblj's solution: the gear rack placed on the frame part like that can jam under stress. Make sure that the gear rack has a smooth base.

Thank you, I went ahead and purchased some of the A-arms from bricklink, I'm going to try it out and see how well they hold up. Thanks for the tips!

[GuiliuG]

Zblj, I think that your design won't work because the cv-joint will touch the A-arm as soon as the suspsension is compressed.

[legomuppet9]

It wont because the pivot point of the axle is on the same point across as the A Arms, if that makes sense, explained badly

[SNIPE]

Yes, the front pivot (the ball joints) are parallel to the hinge in the UV joint. If it wasn't then the turning angle when setting would be less and the axle can come out of the UV joint. however it if still touches the wishbone then maybe move it forward by 0.5L, just don't move it back any more :P

Edited May 31, 2013 by SNIPE

[Zerobricks]

Suspension with the Cv joint parts is same as in 8070. I tried and rack doesnt get stuck with my bricks,

REMEBER THERE IS A CV JOINT IN THE INTERNAL SIDE NOT U JOINT. That allows a narrower design.

Edited May 31, 2013 by Zblj

[Alasdair Ryan]

Suspension with the Cv joint parts is same as in 8070. I tried and rack doesnt get stuck with my bricks,

REMEBER THERE IS A CV JOINT IN THE INTERNAL SIDE NOT U JOINT. That allows a narrower design.

Zblj's design will work,I also checked.

[vmln8r]

Zblj; loving those connections within the H-frame. Very elegant.

[Lipko]

Well, maybe it's just my bricks, but the small shoulders on the H frame (because beams in general are a bit wider in the direction of the holes) always caused me trouble. Not in every actuation and not under stress, but under stress it keeps popping and sometimes it can completely jam. But maybe I was building something wrong.

[Bricktrain]

http://www.brickshelf.com/cgi-bin/gallery.cgi?i=5206795 A design I played with when the portals first came out, I didnt end up using it though, I dont really like the steering geometry with the portal hubs.