PreRunner I-beam Front suspension

[88high]

Hello everyone! Since my roll car didnt turn out so well, I decided to make my 3rd Lego Technic RC-buggy-motor-powered baja Prerunner truck. I have the rear suspensions down, but i decided to go with something fancy for the front... I-beam suspension. I-beam suspension is a type of suspension specially developed for desert trucks, for the big bumps in the terrain. Typical independent suspension has A-arms on each side of the suspension unit, like most of the models from lego. (see the bottom two) I-beam suspension, has two beams that cross eachother, to mount on the opposite side of the frame that the wheel it is going to's side. This results in MASSIVE travel (up to 25 inches) for front suspension. Here is a photo: This is what I would like to make. I want to use a studless mounting bracket, that can fit on to the RC unit's nose. I would like to use some of the current Lego A-arms with the ball joints or ball joint sockets, by extending them by using thin beams. I have sone a bit of experimenting, and i have found it pretty difficult to make a compact system for keeping the beams from hitting eachother. I was either thinking of having one side of the A-arms having beams on the INSIDEs of the A, and the other sides on the outside of the A. However, that was not very compact. Maybe I should do one beam on the inside, and one on theoutside of each beam, to make a altenating patern. Wll, anyways, i just need some help with finding the most compact setup, with a strong bracket, and the use of the RC units steering servo for steering...

Any ideas anybody???

[Saberwing40k]

well, this should work well. i'll get a general idea bashed out in about an hour in LDD, and i'll post it here.

[dhc6twinotter]

Cool project! That should provide some nice travel!

That type of suspension was used on a lot of Fords back in the 90s. Ford even used a similar setup on their 4x4 trucks. Really interesting design.

[Saberwing40k]

well, this should work well. i'll get a general idea bashed out in about an hour in LDD, and i'll post it here.

i'm back, and yes, it has been bashed out. it's not finished, and probably will not be.

anywho, here's an intial version, at rest:

and at maximum travel:

it achieves roughly 7 studs of travel, but did not have enough room for steering.

here's the version with wheels. i have no idea about what kind you want to use, so i used motorcycle wheels.

it is by no means complete, as steering and springs need to be added, but i'll leave that to you. however, be warned that the steering arms are offset by a quarter stud.

this one has nearly 7 studs of travel, as indicated by these pics:

if you want to tweak it, here's the file.

a word of warning, however. with this kind of suspension, you may end up hitting the ground if the vehicle goes over a big enough obstacle, and bottoms out. and another problem, which you likely won't have, is that powering them would be a pain, and i don't know how you would mount springs to achieve full travel. for your purposes, existing independant suspension would be better.

anyway, i'm sure you can figure it out. happy building!

Edited May 14, 2012 by Saberwing40k

[88high]

i'm back, and yes, it has been bashed out. it's not finished, and probably will not be.

anywho, here's an intial version, at rest:

and at maximum travel:

it achieves roughly 7 studs of travel, but did not have enough room for steering.

here's the version with wheels. i have no idea about what kind you want to use, so i used motorcycle wheels.

it is by no means complete, as steering and springs need to be added, but i'll leave that to you. however, be warned that the steering arms are offset by a quarter stud.

this one has nearly 7 studs of travel, as indicated by these pics:

if you want to tweak it, here's the file.

a word of warning, however. with this kind of suspension, you may end up hitting the ground if the vehicle goes over a big enough obstacle, and bottoms out. and another problem, which you likely won't have, is that powering them would be a pain, and i don't know how you would mount springs to achieve full travel. for your purposes, existing independant suspension would be better.

anyway, i'm sure you can figure it out. happy building!

Great idea with the mount! I think it will work, if I add some ball joints for the steering knuckles. I now just have to figure out some steering linkages