steering sys

[snoop]

hello all!!
we are a new group and i need your help about our steering sys.
i want know please what ackermann better if the reverse or the regular ackermann ?
ty

[RollingCamel]

It depends on your tire data. You might want to start with understanding the tires so you could have a better judgment, that's the only way to make a logical decision.

I'm looking forward to do the same thing myself as I was in your position last year.

[The_Man]

If you do not have data then the only real way around keeping it as adjustable as possible and decide during testing based on feedback.

[RollingCamel]

I think that it should be from the high priority things to buy along with Carrol Smith books.

[Mehul Botadra]

Our Conti's prefer a parallel mechanism. I'm still running an Ackerman this year because it gives better feel at turning since the car is going to be really slow. The thing with FSAE is that you never take a turn at 100 kmph, its always around 40-60 kmph, so at these speeds its a little impossible to get past the peak slip angle to reduce steering effort. So its advisable to use an Ackerman.

[Tushar]

Though its very much true that the speed achieved isn't much high, but still in case of skid pad test considerable amount of slip angle is being generated. Because of that we have to develop maximum cornering force on the inner tire to achieve good lateral acceleration. Now to do so we have to go for smaller slip angle on the inner tire, which is possible in case of both reverse Ackerman or parallel steering system. Also, its possible to calculate the right amount of reverse Ackerman if the tire data is known to you.

Reverse Ackerman also provides the outer tire to steer at a higher slip angle and thus is dynamically stable system.

Team Fateh, Thapar University
chugh.tushar@yahoo.com

[Mehul Botadra]

Just for the sake of skidpad, I wouldnt do a lot of fixing around with the steering system! But thank god for shims! http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[Tushar]

Originally posted by Mehul Botadra:
Just for the sake of skidpad, I wouldnt do a lot of fixing around with the steering system! But thank god for shims! http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

Skid pad was just a reference, comparable slip angles are also generated at the time of slaloms where you have a good speed and also during endurance where we have hairpin turns. Well i just know one thing that we always design for the worst condition.

Team Fateh, Thapar University
chugh.tushar@yahoo.com

[Mehul Botadra]

Hahahaha, FSAE is just one thing, design it optimally and not for the worse! No wonder our cars weigh 300kgs and FOS=10! http://fsae.com/groupee_common/emoticons/icon_wink.gif

[exFSAE]

I'd say many cars have a FOS < 1.0

[Tushar]

I think i have never mentioned to over design something so as to have a large FOS and to increase the weight unnecessarily. Well that's my opinion but no issues it depends from team to team.

[Mehul Botadra]

@ Tushar
Agreed!

@ ExFSAE
Hahaha! Those are the cars that are always on the jacks! http://fsae.com/groupee_common/emoticons/icon_smile.gif