Camber, caster, Ackermann

[theo]

you might have to much ackerman in you inside wheel.

 

[kaymo]

maybe, but thats what my steering stops are for. i dont think its too much tho because my steering arms point perfectly at the center of the rear end

 

[theo]

You should attach the tie rods to the bell crank with one center hole. The way you are set up now you have ackerman at the spindles and you are adding more at the steering shaft bell crank. The stops don't effect ackerman.

 

[jamyers]

This image from wikipedia shows what you want your tires to do, regardless of how your steering gear gets you there. From what I gather, having the steering arms point at the center of the rear axle (when the tires are pointed straight ahead) is merely a simple way of achieving this effect. So unless your steering is built the "simple" way, about the only way you can check your Ackermann is to turn the steering wheel and find where the centers of each tire's turning radius is, correct?

 

[theo]

You can achieve ackerman at the spindles and at the bellcrank. Now if you do both then the inner tire has to much angle and the outer one has not enough. If you look at my steering i have my ackerman in the bell crank. My spindles are from AZUSA and the arms of these come off at 90 deg.

[/IMG]

 

[Doc Sprocket]

There are many ways to skin a cat. The question is, what is simplest and most effective. Having the arms facing rearward and pointed at axle centre is one such example. The problem with altering rod mounts at the pitman arm (especially when steering arms face forward) is figuring out exactly how far apart to spread those rod ends.

For the record-

"Reverse Ackermann" does NOT refer to the condition created when steering arms face forward, and/or measurements/adjustments to suit. The phrase "reverse Ackermann" indicates a steering setup wherein the outside tire steers more sharply than the inside tire- which in almost all situations is entirely UNdesirable.

Also- I love the phrases "more Ackermann" and "less Ackermann". Either the principle is properly applied, or it's not. Anybody here "more" circumcised?...

Micro-rant over. Have a great weekend!

 

[jamyers]

...Anybody here "more" circumcised?...

Micro-rant over. Have a great weekend!

Hahaha, your micro-rant is a GREAT way to start the weekend - THANKS!

 

[raposak]

Well I'm larger than most, so I guess i'm more circumcised

 

[Doc Sprocket]

Umm. Yeah-okay. Whatever you gotta tell yerself...

 

[kaymo]

You should attach the tie rods to the bell crank with one center hole. The way you are set up now you have ackerman at the spindles and you are adding more at the steering shaft bell crank. The stops don't effect ackerman.

ok sorry i didnt mean to say that my steering stops are changing the ackermann, but the ackermann effect gets much much greater at full steering lock, so much that its too much. the steering stops keep it from getting there but still allows plenty of turning. maybe i have dont have it completely right by not having the rods closer at the steering shaft, but i couldnt exactly have them on the same point with those type of rods ends anyway, and its the length my rods are so its where they ended up. Either way, my steering is much better setup than it was before. you can tell simply by rolling the cart around in the shop that it turns better.

 

[kaymo]

For the record-

"Reverse Ackermann" does NOT refer to the condition created when steering arms face forward, and/or measurements/adjustments to suit. The phrase "reverse Ackermann" indicates a steering setup wherein the outside tire steers more sharply than the inside tire- which in almost all situations is entirely UNdesirable.

what i described with the steering arms facing forward is reverse ackermann, which is exactly what you described as well. using the term "anti ackermann" was from another article i read... descibing how to reverse the effects of "reverse ackermann" im sorry that you felt the need to rant, but i think we are saying the same thing different ways. i didnt mean to cause confusion, im simply trying to help.

 

[raposak]

I do appreciate all the info. I think i'll tackle this this weekend. So from what I gather, i run a line from the spindle to the center of the rear axle. Than as long as the attachment point of the steering falls on that line then I should be good.

 

[kaymo]

You can achieve ackerman at the spindles and at the bellcrank. Now if you do both then the inner tire has to much angle and the outer one has not enough. If you look at my steering i have my ackerman in the bell crank. My spindles are from AZUSA and the arms of these come off at 90 deg.

so have you measured your ackermann to see if its correct? ive found that its much easier when building a kart to build the ackermann into the steering arms. im not even sure how you would build the correct ackermann into the bellcrank, but every time i messed with adding ackermann angle with the bellcrank, it would give me reverse ackermann.

 

[Doc Sprocket]

Specifically, from the kingpin to rear axle center.

 

[Doc Sprocket]

its much easier when building a kart to build the ackermann into the steering arms. im not even sure how you would build the correct ackermann into the bellcrank, but every time i messed with adding ackermann angle with the bellcrank, it would give me reverse ackermann.

That was the point I was trying to make earlier (a few posts back). Since none of us know precisely where to locate the rod ends into the pitman arm, it's best to use the above tried-and-true method.

 

[Doc Sprocket]

what i described with the steering arms facing forward is reverse ackermann, which is exactly what you described as well. using the term "anti ackermann" was from another article i read... descibing how to reverse the effects of "reverse ackermann" im sorry that you felt the need to rant, but i think we are saying the same thing different ways. i didnt mean to cause confusion, im simply trying to help.

Lost in translation. I think we all get what we're trying to say...

 

[theo]

so have you measured your ackermann to see if its correct? ive found that its much easier when building a kart to build the ackermann into the steering arms. im not even sure how you would build the correct ackermann into the bellcrank, but every time i messed with adding ackermann angle with the bellcrank, it would give me reverse ackermann.

I put the ackerman into the bell crank because I was using AZUSA spindles.
This is what I did to figure out how to make the bell crank:
Draw a line from the spindle to the center of the axle shaft. Calculate that angle to the centerline of the kart, It might be 15 deg.(Guess) Use this measurement to calculate the holes in the bell crank. Each hole should be 15 deg from center of the steering shaft or 30 deg. apart.

 

[babzog]

I put the ackerman into the bell crank because I was using AZUSA spindles.
This is what I did to figure out how to make the bell crank:
Draw a line from the spindle to the center of the axle shaft. Calculate that angle to the centerline of the kart, It might be 15 deg.(Guess) Use this measurement to calculate the holes in the bell crank. Each hole should be 15 deg from center of the steering shaft or 30 deg. apart.

Is there any rule of thumb by which to set the distance from the center of the steering column to the holes? Is there a relation between that distance and the distance between the kingpin center to the tie rod connection point on the steering arm?

 

[theo]

Here is a drawing of a bell crank to go with AZUSA spindles.

[/IMG]

I don't know the measurement off the AZUSA spindles, someone else might know.

 

[jamyers]

Is there any rule of thumb by which to set the distance from the center of the steering column to the holes? Is there a relation between that distance and the distance between the kingpin center to the tie rod connection point on the steering arm?

I'm still reading up, but here's a website that looks to have some great info, particularly if your kart's steering arms point forwards like mine do.
http://www.eland.org.uk/steering.html