Uniball question

[gpbullock]

What are the advantages or disadvantage to mounting Uniballs vertically or horizontally for the upper and lower control arm to uprights connection? When mounting the uniball vertically (so that the lower control arm to uprights attachment hardware are parallel to the ground) it is the uniball and high misalighnment spacers providing the steering angle. Are you able to get the same steering angle range that you would have by mounting the uniball horizontally (similar to Kartek's or BMS's upright configuration? I've read that the uniballs have more strength in vertical than horizontal, is there advantages one way or the other?

[Scott_F]

Welcome to RDC. If you do a search you will find the answers to all of your questions and more.

[BenDotCom]

Superior strength if mounted vertically (bolt parallel to ground). Radial load vs. Axial load. The steering angle is contradicted by a number of things: Uniball size, Cup size, HMA spacers, etc. This does not mean that a proper steering angle cannot be achieved, it is just limited. Often times you can achieve the same angle if the uniball were to be mounted horizontally (bolt pointing toward ground). A recent project I did had the uniballs mounted vertically and I have almost a 30 degree steering angle.

[gpbullock]

Thanks for the explanation. I have spent the last couple of months lurking on this forum and have read so much information
I am in information overload. Sometimes I leave this forum with a headache trying to absorb all of the information from the
many talented engineers and fabricators on this site. I'm getting ready to start up my first offroad ground up build and am trying to
jump off the fence, but need a little push to get me going.

[russcomp]

Thanks for the explanation. I have spent the last couple of months lurking on this forum and have read so much information
I am in information overload. Sometimes I leave this forum with a headache trying to absorb all of the information from the
many talented engineers and fabricators on this site. I'm getting ready to start up my first offroad ground up build and am trying to
jump off the fence, but need a little push to get me going.

i understand the headache :)

[gpbullock]

Yeah, I have been doing the design in Autocad and Solidworks and it seems like everytime I get on here I have to
go back and revise the design because I'll see something new that makes perfect sense to the design for strength
or performance and then it's back to the ole' drawing board.

[Scott_F]

GP, I feel your pain. No matter how much planning and research you do, there will be certain things that you would do differently after you start building. No one can build the perfect vehicle, especially on the first try. I would suggest that you go for it after you are 90% sure of your chassis design, and 99% sure of your suspension design. Any other problems that come up you will solve along the way.

[rharriman]

Yeah, I have been doing the design in Autocad and Solidworks ....


Just curious why you use both??:confused:


Solid works or any 3D modeling program is so much easier to lay things out in and make moving examples. I use Inventor and can't imagine laying anything out using autocad anymore. Drawing a line and making it the length you want is way more flexible then drawing a line the right length. Sorry bout diverting the thread.:D

[gpbullock]

I guess I should have clarified. I've used Autocad and Maya (which isn't great for engineering but great for animation 3d) for 10 years and have used Solidworks but didn't have access to the software either at home or work. I finally just got access to Solidworks so I have been converting everything to Solidworks.

[rharriman]

Sounds good, I was just curious.:)

[desertgoin]

Ben,

Great explanation. How have you been? We have done it both ways here as well. Besides the strength gain in mounting vertical you also have the benefit of no limit of travel due to binding of the uniball/ HM spacer. Although something else always limits it huh?

[CRAIG_HALL]

Recent design project was a 1-1/2" vertical uniball, possibly.Steering angle was just over 31° from top view, but at full bump & lock the uniball sees over 36°. This was using a 3/4" bolt and the misalign was .1875 thick at it's thinnest section. Not sure how much thinner I'd want to go. It usually isn't a cup crashing issue but the misalign & the race.

I've never seen when you need more angle for wheel travel than steering...

[goofballracer]

i went with horizontal uniballs i think you get more travel with them vertical but for my application horizontal worked the best

[FABRICATOR]

IMHO, the strength question is really a moot point. First off, uniballs are generally strong enough mounted in either direction. Secondly, where will your greatest loads come from? Will they be vertical from bumps, or lateral from side impacts? Thirdly, your brakes will apply about as much load on the upper joints as will bumps.

As far as ultimate loads, there is little distinction between bottoming out, and side impact from rocks, birms, or rolling over. Either one can be of a magnitude that damages these or other components. Joint strength is somewhat compromised with high angles. But which creates more vulnerability; high suspension angle or high turning angle? You might factor in some sort of weight to speed ratio, or position them for longer life, but for dezert racing I see no preference for strength.

Builders who have actually driven dezert race vehicles would know why fast steering and sharp turning angle is important. It has little to do with turning sharp but evertything to do with controlling slides. The faster and sharper the better.