96DXCivic
96DXCivic Reader
4/15/09 5:33 p.m.

I don't really know much about rock crawlers. So I was wondering how rock crawlers did swaybars. Are they just like a standard swaybar? And can anyone send me to a website that has info on this?

jgp1843
jgp1843 HalfDork
4/15/09 5:38 p.m.

Generally they don't use swaybars because they limit axle articulation. The idea is to keep the wheels on the ground. Even serious production-based vehicles that are used in terrain that requires lots of wheel travel will use quick disconnects on their swaybar endlinks so they can disconnect for the tough stuff, then reconnect for the drive home.

96DXCivic
96DXCivic Reader
4/15/09 5:54 p.m.

I am currently working on the ASME Moonbuggy Competition. We have about 10" of travel but major body roll problems. So we are trying to find a solution and I was wondering about swaybars.

MA2LA
MA2LA New Reader
4/15/09 6:10 p.m.

its very comon for very bilt rock rig to use a stock car style swaybar. mostly we've used them in the rear to help balance it out. fi you look on http://www.pirate4x4.com/forum/ you should find some good info.

ReverendDexter
ReverendDexter Reader
4/15/09 6:19 p.m.

Be careful with pirate4x4 - they are NOT newb friendly, so make sure you word your questions well, lol.

Keith
Keith GRM+ Memberand SuperDork
4/15/09 7:56 p.m.

Could you address the roll problem with low-speed shock damping? I know it won't affect the ultimate roll, but it might slow it down enough to make the buggy transition well.

Tighe
Tighe New Reader
4/15/09 9:00 p.m.
ReverendDexter wrote: Be careful with pirate4x4 - they are NOT newb friendly, so make sure you word your questions well, lol.

This is how things should be. Love it.

YaNi
YaNi Reader
4/15/09 9:00 p.m.

Could you use something like an air locker to able to connect 2 halves of the bar together in the center? When maximum articulation was needed you could hit a button and it would function like it didnt have a sway bar.

jgp1843
jgp1843 HalfDork
4/15/09 10:34 p.m.

I just looked up a couple of university websites on the ASME moonbuggy competition - whoops, totally different sort of vehicle from what I envisioned from your first post. What a neat concept! And wild looking vehicles. My guess would be really soft springs, good damping, and I can see why you're concerned with stability.Would some sort of gyroscopic device in the chassis (maybe a mechanical flywheel) help, or would it be too heavy and too hard to spin up? Do both pedalers provide forward drive, or does one go forward and the other backward? Strange vehicles, but the project looks like fun. What kind of weight are you aiming for?

matt
matt New Reader
4/15/09 10:43 p.m.

stiffer springs in the rear and playing with the 4 link mounting points will help and shock dampeneing.

oh wait, im talking about rc rock crawlers

curtis73
curtis73 GRM+ Memberand Reader
4/16/09 12:46 a.m.

It depends on how much street vs rock crawling you do. Hardcore offroad vehicles don't have them at all. Mostly street vehicles like my F150 have the stock bars in place. In never need that much articulation. Vehicles in the middle usually have stock bars with quick disconnects for the trail.

thatsnowinnebago
thatsnowinnebago GRM+ Memberand HalfDork
4/16/09 2:10 a.m.

1, 2, 3, 4, 5. <--- There's five different options for sway bars for on/off road usage. Is that what you were looking for?

Jensenman
Jensenman SuperDork
4/16/09 8:46 a.m.
96DXCivic wrote: I am currently working on the ASME Moonbuggy Competition. We have about 10" of travel but major body roll problems. So we are trying to find a solution and I was wondering about swaybars.

The original Hydrolastic fluid suspended Minis had a setup where each corner of the car had a rubber bellows connected to the others via tubes. If the left front suspension had upward travel, the fluid went to another bellows which then extended.

Maybe you could come up with something similar, using braided brake lines connected to the shocks? Or even use air bladders with plastic tubes (light weight).

DILYSI Dave
DILYSI Dave SuperDork
4/16/09 8:56 a.m.
Jensenman wrote:
96DXCivic wrote: I am currently working on the ASME Moonbuggy Competition. We have about 10" of travel but major body roll problems. So we are trying to find a solution and I was wondering about swaybars.
The original Hydrolastic fluid suspended Minis had a setup where each corner of the car had a rubber bellows connected to the others via tubes. If the left front suspension had upward travel, the fluid went to another bellows which then extended. Maybe you could come up with something similar, using braided brake lines connected to the shocks? Or even use air bladders with plastic tubes (light weight).

This has been done in rock crawling as well.

EDIT - here's the vehicle I was thinking of - http://www.scorpion4x4.com/ It uses air bladders on each corner that are plumbed together.

The revolutionary design for the Scorpion's suspension allows it to keep all four tires on the ground with virtually equal ground pressure in almost any situation. The Scorpion can conquer terrain that other vehicles cannot. And, the Scorpion handles the terrain without the bone-jarring ride characteristic of off-roaders. This allows the Scorpion to be used in a rescue role to provide a soft ride for injured persons extracted from rough terrain. The terrain benefits, as well, as the Scorpion is gentle on the ground it traverses
Cotton
Cotton Reader
4/16/09 9:00 a.m.

I use extended sway bar links with quick disconnects on my Jeep. I got them from JKS. Keep them connected on the street and disconnect for the slower speed offroad stuff.

njansenv
njansenv Reader
4/16/09 3:52 p.m.

You can do some really neat things with 4 hydraulic cylinders and a couple accumulators, but that would be relatively heavy. Keith is right: low speed damping can make a huge difference in transient conditions.

jgp1843
jgp1843 HalfDork
4/16/09 3:53 p.m.

The OP's project is WAY different than what any of us have been thinking (except for maybe the hydrolastic - might have an application). Google ASME Moonbuggy - these things are wild!

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