Uncommon Suspensions

[DrJB]

During a visit to an auto show few years ago, Porsche had a mock-up of one of their cars. I do not recall which one it was, but for sure I took photos of the suspension as it was the first time (for me) to see such unique geometry. I've tried to reproduce this in the past with lego, but was not too persistent and quickly gave up. Anyone knows of a Lego replica or better yet, brave enough to attempt one? If so, here are some pictures to help with your new project. If you look closely, you'll notice both front and rear have anti-roll bars. You can tell the front from the rear by the steering link, connecting the left/right tires/wheels.

Also, what other suspensions have you reproduced with Lego, or at least plan to? I must admit I was pleasantly surprised by the Arocs. The suspension there was rather unique. It's also the only set that took me 4 days to build (on and off). While the truck is boxy and the pneumatics sluggish, it is such working suspension/drive-train details that exemplify (to me) what Technic is all about.

Edited May 4, 2016 by DrJB

[Saberwing40k]

This looks like modified double wishbone suspension, using pushrods. I'm thinking it is either one of their Le Mans cars, or maybe a prototype 918. Pushrod suspension has been implemented in Lego before, with set 42000. But this particular variant, I have not seen before.

[Lipko]

II don't know how uncommon, but I made a solid axle with push-rod suspension and with Watt's linkage instead of Panhard rod to restrict sideways movements of the axles.

[DrJB]

This looks like modified double wishbone suspension, using pushrods. I'm thinking it is either one of their Le Mans cars, or maybe a prototype 918. Pushrod suspension has been implemented in Lego before, with set 42000. But this particular variant, I have not seen before.

Correct, it is a double wishbone, but in contrast with the 'classical' WB, this one has the spring and damper in very 'unique orientations, most likely because of limited vertical space (I know there are other reasons).

II don't know how uncommon, but I made a solid axle with push-rod suspension and with Watt's linkage instead of Panhard rod to restrict sideways movements of the axles.

This is very interesting, I may have to build it to understand how it fully works.

[Didumos69]

The suspension appears to be from the Porsche Carrera GT. Indeed interesting how the pushrods have been positioned. Given all the rare angles I'm affraid you end up using more space instead of less (EDIT: compared to a standard sideways positioned pushrod) when you build this with LEGO.

Source: http://forums.diesel...showtopic=22007

Edited May 4, 2016 by Didumos69

[Didumos69]

Also, what other suspensions have you reproduced with Lego, or at least plan to?

For my Steppenwolf I tried to reproduce this Citroen front suspension (from 1935!!); an uncommon combination of double wishbone and a lengthwise torsion bar. The torsion bar is attached to the lower wishbone:

The combination of a shockabsorber and a torsion bar works out very well in LEGO. The main difference between my implementation and the original Citroen suspension is that I placed the tooth rack behind, and the shockabsorber in front of the axles. The geometry also incorporates drive, caster angle, kingpin inclination, active camber (shorter upper wishbone) and Ackermann steering. These are cutouts from the front module:

Close-ups of the real-life build:

Like in the orginal, the torsion can be adjusted. In this case by using different parts to secure the torsion axle:

also zooms in on the front suspension. Edited May 4, 2016 by Didumos69

[mortenm]

There is something similar in the 8674 Ferrari F1 Racer:

[steph77]

I use exact l'y this setup on m'y lmp1 here: http://www.eurobricks.com/forum/index.php?showtopic=108469

[Jim]

This is very interesting, I may have to build it to understand how it fully works.

Please don't quote images.

[DrJB]

Please don't quote images.

Agreed, I usually try to avoid that but, forgot this time. Cheers

[DrJB]

Take a look at Nico's Citroen 2CV suspension. Springs are positioned horizontally!

http://www.eurobricks.com/forum/index.php?showtopic=59250&st=200

I did an LXF some time back, try it out:

http://www.brickshel...ry.cgi?f=537067

[Mantarri]

Funny you posting this, as I'm doing suspension in my next MOC.

Edited May 4, 2016 by XtremeBuilder

[PKW]

I built this particular suspension system to have a good 6x6 trial truck with steering front wheels, i think this is a "7 link double live axle with pushrods" am I right? :laugh:

anyway it works really well especially because you can lift the 1st or the 2nd axle alone and the truck remain leveled

[Victor Imaginator]

PKW, yes) That's what called "uncommon")

[Didumos69]

PKW, yes) That's what called "uncommon")

Agreed.

Reminds me of Rocker-Bogie suspension as used in Mars Rovers. Should also be perfectly doable with LEGO. This setup makes sure the vehicles weight is evenly divided over all 6 wheels.

EDIT: Has actually been built with LEGO by many builders. Here's one example:

Edited May 4, 2016 by Didumos69

[JJ2]

I have been thinking about building a rocker bogie suspension but I don't know how to stabilize the body.

[Didumos69]

I have been thinking about building a rocker bogie suspension but I don't know how to stabilize the body.

As I understand the position of the body is regulated by using a differential. Secure the diffs output axles to the left and right rocker and secure the input axle to the body and the position of the body should be the average of the positions of the rockers. But using a standard differential will probably give too much slack.

Edited May 4, 2016 by Didumos69

[JJ2]

That's what I thought but I am no Mars Rover scientist

[Lipko]

Why use a differential if it's fixed anyway? Just use big enough gears to reduce slack.

[Didumos69]

Why use a differential if it's fixed anyway?

The gears inside the diff can rotate, making the left and right rockers communicate and making the diff itself average out between the rockers.

EDIT: @Lipko, I think I misunderstood. You're right, you don't need a normal diff. You can simply regard the body itself as the diff.

Edited May 4, 2016 by Didumos69

[zux]

That's what I thought but I am no Mars Rover scientist

That's correct hint! Check the Mars Curiosity rover (21104 set). There is a stabiliser on top of the body, which levels the rockers - once one goes up another is being pushed down.

[JJ2]

That's correct hint! Check the Mars Curiosity rover (21104 set). There is a stabiliser on top of the body, which levels the rockers - once one goes up another is being pushed down.

Yea that's what inspired me to do something like this but I am going to do the mars exploration rover set

[DrJB]

I was secretely hoping the upcoming Porsche to have the suspension I showed in the first post. Regrettably, it won't

Edited May 9, 2016 by DrJB

[1974]

Great thread JB

Found this interesting link while looking for different suspension types :

http://www.susprog.com/susptype.htm

Cheers,

Ole

[Didumos69]

If've been intrigued by the MAZ 537 rear axles lately. A double wishbone setup for each of the 4 rear wheels combined with a suspension equalizer (bogie) on each side. No springs or shockabsorbers involved. Also quite uncommon I think.

I'm currently trying to build this.

Edited May 11, 2016 by Didumos69